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Guo, Qi. "Minkowski Measure of Asymmetry and Minkowski Distance for Convex Bodies." Doctoral thesis, Uppsala : Matematiska institutionen, Univ. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4286.
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Jin, Limiao. "Formule di Minkowski." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19249/.
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Dopo aver introdotto le quantità fondamentali per lo studio della curvatura delle superfici, mappa di Gauss, curvatura media e gaussiana, ed aver enunciato e provato il teorema della divergenza nello spazio tridimensionale, si dimostreranno le formule di Minkowski; in ultimo saranno presentati come corollari i teoremi di Hilbert-Liebmann e di Jellett.
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Rousset, Mireille. "Sommes de Minkowski de triangles." Phd thesis, Université Joseph Fourier (Grenoble), 1996. http://tel.archives-ouvertes.fr/tel-00005017.
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La modélisation géométrique d'un problème de gestion de la fabrication des mélanges (faisabilité simultanée de deux mélanges) fait apparaître des polytopes nouveaux résultant de la somme de triangles particuliers qui dans ce contexte sont appelés convexes de 2-mélanges. De façon plus générale, la somme de triangles peut être considérée comme la généralisation des zonotopes (somme de segments). De ce point de vue, l'étude menée ici fait apparaître que la propriété de zone associée à un segment du zonotope se généralise à trois demi-zones associées à chaque triangle; et que la complexité combinatoire (nombre de faces du polytope), par rapport au nombre de sommandes, est du même ordre de grandeur que celle des zonotopes. On traite également le problème de la construction de tels polytopes, des algorithmes optimaux en temps sont proposés. Concernant le problème particulier des mélanges, le premier cas non trivial est celui de mélanges à trois composantes qui nous place en dimension 6. L'appartenance d'un point au convexe de 2-mélanges détermine la faisabilité simultanée des mélanges. Les facettes de ce polytope sont décrites, en détail, dans le cas de la dimension 6, dans le but d'obtenir des conditions de faisabilité des deux mélanges. Le problème de la décomposition de polytopes en somme de Minkowski de polytopes plus simples est exposé, ainsi que les principaux résultats existant.
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Düvelmeyer, Nico. "Selected Problems from Minkowski Geometry." Doctoral thesis, Universitätsbibliothek Chemnitz, 2006. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200601961.
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Die Dissertation behandelt zwei Gebiete der Geometrie endlichdimensionaler Banach-Räume (Minkowski-Geometrie). Der erste Schwerpunkt liegt dabei auf Winkelmassen und Winkelhalbierenden. Dafür gibt es verschiedene Verallgemeinerungen dieser Euklidischen Konzepte, die im allgemeinen in Minkowski-Räumen verschieden sind. Es werden alle Minkowski-Räume charakterisiert, in welchen zwei dieser Konzepte für alle möglichen Winkel das selbe Maß oder die selben Winkelhalbierenden liefern. Der zweite Teil der Dissertation behandelt die Einbettung von metrischen Räumen in Minkowski-Räume. Dabei steht die Einbettung in beliebige geeignete Minkowski-Räume fester Dimension im Mittelpunkt. Hauptergebnis ist hier die vollständige Klassifikation aller 2-Abstands-Mengen in Minkowski-Ebenen, d.h., aller möglichen Mengen von Punkten einer Minkowski-Ebene, so dass zwischen diesen Punkten nur zwei verschiedene positive Abstandswerte auftretenThis dissertation deals with two geometric subjects in finite dimensional Banach spaces (Minkowski geometry). The first topics are angle measures and angular bisectors. There are several possibilities to generalize these Euclidean concepts, which yield in general distinct geometrical objects in Minkowski spaces. A characterization is given for Minkowski spaces, for which two such concepts yield for all possible angles the same angular measure or the same angular bisector. The second part of the dissertation deals with embeddings of metric spaces into Minkowski spaces. It focuses on embeddings into some arbitrary suitable Minkowski space of prescribed dimension. The major result is the complete classification of all 2-distance sets in Minkowski planes, i.e., of all subsets of points of a Minkowski plane such that there are only two different positive distance values between these points
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Fankhänel, Andreas. "Metrical Problems in Minkowski Geometry." Doctoral thesis, Universitätsbibliothek Chemnitz, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-95007.
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In this dissertation we study basic metrical properties of 2-dimensional normed linear spaces, so-called (Minkowski or) normed planes.
In the first chapter we introduce a notion of angular measure, and we investigate under what conditions certain angular measures in a Minkowski plane exist. We show that only the Euclidean angular measure has the property that in an isosceles triangle the base angles are of equal size. However, angular measures with the property that the angle between orthogonal vectors has a value of pi/2, i.e, a quarter of the full circle, exist in a wider variety of normed planes, depending on the type of orthogonality. Due to this we have a closer look at isosceles and Birkhoff orthogonality. Finally, we present results concerning angular bisectors.
In the second chapter we pay attention to convex quadrilaterals. We give definitions of different types of rectangles and rhombi and analyse under what conditions they coincide. Combinations of defining properties of rectangles and rhombi will yield squares, and we will see that any two types of squares are equal if and only if the plane is Euclidean. Additionally, we define a ``new\'\' type of quadrilaterals, the so-called codises. Since codises and rectangles coincide in Radon planes, we will explain why it makes sense to distinguish these two notions. For this purpose we introduce the concept of associated parallelograms.
Finally we will deal with metrically defined conics, i.e., with analogues of conic sections in normed planes. We define metric ellipses (hyperbolas) as loci of points that have constant sum (difference) of distances to two given points, the so-called foci. Also we define metric parabolas as loci of points whose distance to a given point equals the distance to a fixed line. We present connections between the shape of the unit ball B and the shape of conics. More precisely, we will see that straight segments and corner points of B cause, under certain conditions, that conics have straight segments and corner points, too. Afterwards we consider intersecting ellipses and hyperbolas with identical foci. We prove that in special Minkowski planes, namely in the subfamily of polygonal planes, confocal ellipses and hyperbolas intersect in a way called Birkhoff orthogonal, whenever the respective ellipse is large enough.
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Taylor, Thomas E. "Differential geometry of Minkowski spaces." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq24990.pdf.
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Troncoso, Rey Perla. "Extending Minkowski norm illuminant estimation." Thesis, University of East Anglia, 2012. https://ueaeprints.uea.ac.uk/41970/.
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The ability to obtain colour images invariant to changes of illumination is called colour constancy. An algorithm for colour constancy takes sensor responses - digital images - as input, estimates the ambient light and returns a corrected image in which the illuminant influence over the colours has been removed. In this thesis we investigate the step of illuminant estimation for colour constancy and aim to extend the state of the art in this field. We first revisit the Minkowski Family Norm framework for illuminant estimation. Because, of all the simple statistical approaches, it is the most general formulation and, crucially, delivers the best results. This thesis makes four technical contributions. First, we reformulate the Minkowski approach to provide better estimation when a constraint on illumination is employed. Second, we show how the method can (by orders of magnitude) be implemented to run much faster than previous algorithms. Third, we show how a simple edge based variant delivers improved estimation compared with the state of the art across many datasets. In contradistinction to the prior state of the art our definition of edges is fixed (a simple combination of first and second derivatives) i.e. we do not tune our algorithm to particular image datasets. This performance is further improved by incorporating a gamut constraint on surface colour -our 4th contribution. The thesis finishes by considering our approach in the context of a recent OSA competition run to benchmark computational algorithms operating on physiologically relevant cone based input data. Here we find that Constrained Minkowski Norms operi ii ating on spectrally sharpened cone sensors (linear combinations of the cones that behave more like camera sensors) supports competition leading illuminant estimation.
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Sacramento, Andrea de Jesus. "Curvas no espaço de Minkowski." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/55/55135/tde-15092015-163612/.
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Nesta tese, investigamos a geometria de curvas no 3-espaço e no 4-espaço de Minkowski usando a teoria de singularidades, mais especificamente, a teoria de contato. Para isto, estudamos as famílias de funções altura e de funções distância ao quadrado sobre as curvas. Os conjuntos discriminantes e conjuntos de bifurcação destas famílias são ferramentas essenciais para o desenvolvimento deste trabalho. Para curvas no 3-espaço de Minkowski, estudamos seus conjuntos focais e conjunto de bifurcação da família de funções distância ao quadrado sobre estas curvas para investigar o que acontece próximo de pontos tipo luz. Estudamos também os conjuntos focais e conjuntos de bifurcação esféricos de curvas nos espaços de Sitter do 3-espaço e do 4-espaço de Minkowski. Definimos imagens normal Darboux pseudo-esféricas de curvas sobre uma superfície tipo tempo no 3-espaço de Minkowski e estudamos as singularidades e propriedades geométricas destas imagens normal Darboux. Além disso, investigamos a relação da imagem normal Darboux de Sitter (hiperbólica) de uma curva tipo espaço em S21 com a superfície tipo luz ao longo desta curva tipo espaço. Definimos as superfícies horoesférica e dual hiperbólica de curvas tipo espaço no espaço de Sitter S31 e estudamos estas superfícies usando técnicas da teoria de singularidades. Damos uma relação entre estas superfícies do ponto de vista de dualidades Legendrianas. Finalmente, consideramos curvas sobre uma hipersuperfície tipo espaço no 4-espaço de Minkowski e definimos a superfície hiperbólica desta curva. Estudamos a geometria local da superfície hiperbólica e da curva hiperbólica, que é definida como sendo o local das singularidades da superfície hiperbólica.We study in this thesis the geometry of curves in Minkowski 3-space and 4-space using singularity theory, more specifically, the contact theory. For this we study the families of height functions and of the distance square functions on the curves. The discriminant sets and bifurcation sets of these families are essential tools in our work. For curves in Minkowski 3-space, we study their focal sets and the bifurcation set of the family of the distance square functions on these curves in order to investigate what happens near the lightlike points. We also study the spherical focal sets and bifurcation sets of curves in the de Sitter space in Minkowski 3-space and 4-space. We define pseudo-spherical normal Darboux images of curves on a timelike surface in Minkowski 3-space and study the singularities and geometric properties of these normal Darboux images. Furthermore, we investigate the relation of the de Sitter (hyperbolic) normal Darboux image of a spacelike curve in S21 with the lightlike surface along this spacelike curve. We define the horospherical and hyperbolic dual surfaces of spacelike curves in de Sitter space S31 and study these surfaces using singularity theory technics. We give a relation between these surfaces from the view point of Legendrian dualities. Finally, we consider curves on a spacelike hypersurface in Minkowski 4-space and define the hyperbolic surface of this curve. We study the local geometry of the hyperbolic surface and of the hyperbolic curve that is defined as being the locus of singularities of the hyperbolic surface.
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Giannerini, Davide. "La disuguaglianza di Brunn-Minkowski." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23711/.
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Questa tesi ha come argomento la disuguaglianza di Brunn-Minkowski, risultato fondamentale nella teoria della geometria convessa.
Essa riguarda la relazione esistente tra i volumi di due corpi convessi (insiemi compatti, convessi e non vuoti) e il volume del corpo convesso ottenuto come "combinazione convessa" dei due. Nella tesi presentiamo una delle dimostrazioni che poggia sulla disuguaglianza di Prèkopa-Leindler.
I primi capitoli della tesi sono rivolti alla presentazione, il più possibile dettagliata, dei prerequisiti. La parte più impegnativa
e più tecnica della tesi è costituita dalla preparazione della dimostrazione della disuguaglianza di Prèkopa-Leindler.
Essa si basa su importanti risultati della teoria della misura, la cui trattazione viene sviluppata nei primi capitoli, riguardanti le
funzioni monotone, le funzioni a variazione limitata e le funzioni assolutamente continue.
Infatti necessitiamo del teorema di derivabilità q.o. delle funzioni monotone, che viene qui dimostrato facendo uso del famoso
lemma di Vitali, del Teorema fondamentale del calcolo integrale di Lebesgue, della formula di derivazione di funzioni composte per
funzioni non regolari, di un risultato di validità della formula della catena e di una opportuna formulazione di integrazione per
sostituzione per l'integrale di Lebesgue. Altro risultato utile è la disuguaglianza tra la media aritmetica e la media geometrica.
Nel capitolo finale, forniamo un'applicazione rilevante, quanto naturale, della disuguaglianza di Brunn-Minkowski:
la disuguaglianza isoperimetrica per i corpi convessi. Essa viene dimostrata utilizzando la cosiddetta formula di Steiner e la prima disuguaglianza di Minkowski per i corpi convessi. Mostriamo inoltre che dalla caratterizzazione degli insiemi che danno l'uguaglianza per la disuguaglianza di Brunn-Minkowski, è possibile dimostrare che i corpi convessi che danno l'uguaglianza per la disuguaglianza isoperimetrica sono tutte e sole le palle euclidee.
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Ramos, Luciano de Melo. "Teorema de Schur no plano de Minkowski e caracterização de hélices inclinadas no espaço de Minkowski." Universidade Federal de São Carlos, 2013. https://repositorio.ufscar.br/handle/ufscar/5893.
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A classical theorem of differential geometry of curves in Euclidean space is the Schur's Theorem, that was proof by A. Schur in 1921, when both curvatures agree pointwise [3]. The proof in the general case was proved in 1925 by E. Schmidt in [4]. The first objective in this dissertation is to present Lorentzian version of Schur's Theorem in the Minkowski plane. Then we will show some applications due to R. López [1]. In the Minkowski space we will see that the Schur's Theorem is false. The second objective is show a characterization of slant helices in the Minkowski space obtained by A. T. Ali and R. López in [2], which extends naturally a characterization of slant helices in Euclidean space obtained in 2004 by S. Izumiya And N. Takeuchi [6]. We conclude with an application that characterization of slant helices [2].
Um resultado clássico da geometria diferencial de curvas no espaço euclidiano é o Teorema de Schur, que primeiro foi provado em 1921 por A. Schur em [3] no caso em que as curvaturas das curvas coincidem pontualmente. O caso geral do teorema foi provado em 1925 por E. Schmidt em [4]. O primeiro objetivo desta dissertação é apresentar uma versão do Teorema de Shur para o plano de Minkowski. Em seguida, mostraremos algumas aplicações desse resultado feitas por R. López em [1]. No caso do espaço de Minkowski veremos que o Teorema de Schur é falso. O segundo objetivo é mostrar uma caracterização das hélices inclinadas no espaço de Minkowski obtidas por A. T. Ali e R. López em [2], a qual estende de forma natural a caracterização de hélices inclinadas no espaço euclidiano obtida em 2004 por S. Izumiya e N. Takeuchi [6]. Concluímos esta dissertação provando uma caracterização de hélices inclinadas obtida em [2].
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Seater, Robert. "Minkowski sum decompositions of convex polygons." Diss., Connect to the thesis, 2002. http://hdl.handle.net/10066/1479.
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SILVA, MARCELO CHAVES. "ISOPERIMETRIC PROBLEMS IN THE MINKOWSKI PLANE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=25618@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
O objetivo principal deste trabalho é resolver o problema isoperimétrico no plano de Minkowski, isto é, determinar dentre todas as curvas convexas, fechadas, simples e suaves de perímetro fixo de um plano munido com uma norma qualquer, qual é aquela que delimita a maior área. Mostraremos que a solução para este problema não é necessariamente o círculo como no caso euclideano e sim uma curva conhecida como isoperimetrix. Para isto, vamos demonstrar a desigualdade de Minkowski a partir do conceito de área mista. Em seguida, vamos determinar se há outros casos (além do caso euclideano) em que o círculo coincide com o isoperimetrix. Também iremos mostrar que o perímetro da bola nestes planos pode assumir qualquer valor real entre seis e oito, sendo seis quando a bola for um hexágono regular afim e oito quando for um paralelogramo.
The main objective of this work is to solve the isoperimetric problem in the Minkowski plane, i. e., determine among all smooth simple closed convex curves of a normed plane with fixed perimeter, what is that which defines the largest area. We will show that the solution to this problem is not necessarily the circle as in the Euclidean case, but a curve known as isoperimetrix. For this, we will demonstrate the Minkowski inequality from the concept of mixed area. Then, we determine if there are other cases (apart from the Euclidean case) in which the circle coincides with the isoperimetrix. We will also show that the ball perimeter in a normed plane can take any real value between six and eight. It is six when the ball is an affine regular hexagon and eight when it is a parallelogram.
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Bizzocchi, Debora. "Einstein e Minkowski sulla relatività ristretta." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/6270/.
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Brunswic, Léo. "Surfaces de Cauchy polyédrales des espaces temps plats singuliers." Thesis, Avignon, 2017. http://www.theses.fr/2017AVIG0420/document.
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L'étude des espaces-temps plats singuliers munis d'une surface de Cauchy polyédrale est motivée par leur rôle de model jouet de gravité quantique proposé par Deser, Jackiw et 'T Hooft. Cette thèse porte sur les paramétrisations de certaines classes d'espaces-temps plat singuliers : les espaces-temps plats avec particules massives et BTZ Cauchy-compacts maximaux. Deux paramétrisations sont proposées, l'une reposant sur une extension du théorème de Mess aux espaces-temps plats avec BTZ et la surface de Penner-Epstein, l'autre reposant sur une généralisation du théorème d'Alexandrov aux espaces-temps plats avec particules massives et BTZ. Ce travail propose également une amorce de cadre théorique permettant de considérer des espaces-temps singuliers plus générauxThe study of singular flat spacetimes with polyhedral Cauchy-surfaces is motivated by the quantum gravity toy model role they play in the seminal work of Deser, Jackiw and 'T Hooft. This thesis study parametrisations of classes of singular flat spacetimes : Cauchy-compact maximal flat spacetimes with massive and BTZ-like singularities. Two parametrisations are constructed. The first is based on an extension of Mess theorem to flat spacetimes with BTZ and Penner-Epstein convex hull construction. The second is based on a generalisation of Alexandrov polyhedron theorem to radiant Cauchy-compact flat spacetimes with massive and BTZ-like singularities. This work also initiate a wider theoretical background that encompass singular spacetimes
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Bachmaier, Fabian. "The free particle on q-Minkowski space." [S.l.] : [s.n.], 2003. http://edoc.ub.uni-muenchen.de/archive/00001917.
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Swanepoel, Konrad Johann. "The local Steiner problem in Minkowski spaces." Doctoral thesis, Universitätsbibliothek Chemnitz, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-201000873.
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The subject of this monograph can be described as the local properties of geometric Steiner minimal trees in finite-dimensional normed spaces. A Steiner minimal tree of a finite set of points is a shortest connected set interconnecting the points. For a quick introduction to this topic and an overview of all the results presented in this work, see Chapter 1. The relevant mathematical background knowledge needed to understand the results and their proofs are collected in Chapter 2. In Chapter 3 we introduce the Fermat-Torricelli problem, which is that of finding a point that minimizes the sum of distances to a finite set of given points. We only develop that part of the theory of Fermat-Torricelli points that is needed in later chapters. Steiner minimal trees in finite-dimensional normed spaces are introduced in Chapter 4, where the local Steiner problem is given an exact formulation. In Chapter 5 we solve the local Steiner problem for all two-dimensional spaces, and generalize this solution to a certain class of higher-dimensional spaces (CL spaces). The twodimensional solution is then applied to many specific norms in Chapter 6. Chapter 7 contains an abstract solution valid in any dimension, based on the subdifferential calculus. This solution is applied to two specific high-dimensional spaces in Chapter 8. In Chapter 9 we introduce an alternative approach to bounding the maximum degree of Steiner minimal trees from above, based on the illumination problem from combinatorial convexity. Finally, in Chapter 10 we consider the related k-Steiner minimal trees, which are shortest Steiner trees in which the number of Steiner points is restricted to be at most kDas Thema dieser Habilitationsschrift kann als die lokalen Eigenschaften der geometrischen minimalen Steiner-Bäume in endlich-dimensionalen normierten Räumen beschrieben werden. Ein minimaler Steiner-Baum einer endlichen Punktmenge ist eine kürzeste zusammenhängende Menge die die Punktmenge verbindet. Kapitel 1 enthält eine kurze Einführung zu diesem Thema und einen Überblick über alle Ergebnisse dieser Arbeit. Die entsprechenden mathematischen Vorkenntnisse mit ihren Beweisen, die erforderlich sind die Ergebnisse zu verstehen, erscheinen in Kapitel 2. In Kapitel 3 führen wir das Fermat-Torricelli-Problem ein, das heißt, die Suche nach einem Punkt, der die Summe der Entfernungen der Punkte einer endlichen Punktmenge minimiert. Wir entwickeln nur den Teil der Theorie der Fermat-Torricelli-Punkte, der in späteren Kapiteln benötigt wird. Minimale Steiner-Bäume in endlich-dimensionalen normierten Räumen werden in Kapitel 4 eingeführt, und eine exakte Formulierung wird für das lokale Steiner-Problem gegeben. In Kapitel 5 lösen wir das lokale Steiner-Problem für alle zwei-dimensionalen Räume, und diese Lösung wird für eine bestimmte Klasse von höher-dimensionalen Räumen (den sog. CL-Räumen) verallgemeinert. Die zweidimensionale Lösung wird dann auf mehrere bestimmte Normen in Kapitel 6 angewandt. Kapitel 7 enthält eine abstrakte Lösung die in jeder Dimension gilt, die auf der Analysis von Subdifferentialen basiert. Diese Lösung wird auf zwei bestimmte höher-dimensionale Räume in Kapitel 8 angewandt. In Kapitel 9 führen wir einen alternativen Ansatz zur oberen Schranke des maximalen Grads eines minimalen Steiner-Baums ein, der auf dem Beleuchtungsproblem der kombinatorischen Konvexität basiert ist. Schließlich betrachten wir in Kapitel 10 die verwandten minimalen k-Steiner-Bäume. Diese sind die kürzesten Steiner-Bäume, in denen die Anzahl der Steiner-Punkte auf höchstens k beschränkt wird
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Bachmaier, Fabian. "The free particle on q-Minkowski space." Diss., lmu, 2004. http://nbn-resolving.de/urn:nbn:de:bvb:19-19176.
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Le, Thanh Hoang Nhat. "Sur la dimension de Minkowski des quasicercles." Phd thesis, Université d'Orléans, 2012. http://tel.archives-ouvertes.fr/tel-00762750.
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Saad, A. "Generalisation of Clairaut's theorem to Minkowski spaces." Thesis, Coventry University, 2013. http://curve.coventry.ac.uk/open/items/0660ac3c-530d-497a-825a-e7a8c0a4eebd/1.
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The geometry of surfaces of rotation in three dimensional Euclidean space has been studied widely. The rotational surfaces in three dimensional Euclidean space are generated by rotating an arbitrary curve about an arbitrary axis. Moreover, the geodesics on surfaces of rotation in three dimension Euclidean space have been considered and discovered. Clairaut's [1713-1765] theorem describes the geodesics on surfaces of rotation and provides a result which is very helpful in understanding all geodesics on these surfaces. On the other hand, the Minkowski spaces have shorter history. In 1908 Minkowski [1864-1909] gave his talk on four dimensional real vector space, with asymmetric form of signature (+,+,+,-). In this space there are different types of vectors/axes (space-like- time-like and null) as well as different types of curves (space-like- time-like and null). This thesis considers the different types of axes of rotations, then creates three different types of surfaces of rotation in three dimensional Minkowski space, and generates Clairaut's theorem to each type of these surfaces, it also explains the analogy between three dimensional Euclidean and Minkowskian spaces. Moreover, this thesis produces different types of surfaces of rotation in four dimensional Minkowski spaces. It also generalises Clairaut's theorem for these surfaces of rotations in four dimensional Minkowski space. Then we see how Clairaut's theorem characterization carries over to three dimensional and four dimensional Minkowski spaces.
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Mullin, Trista A. "The Brunn-Minkowski Inequality and Related Results." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1527246504656487.
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Conley, Randolph M. "A survey of the Minkowski?(x) function." Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=3055.
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Smukler, Micah. "Geometry and Topology of the Minkowski Product." Scholarship @ Claremont, 2003. https://scholarship.claremont.edu/hmc_theses/155.
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The Minkowski product can be viewed as a higher dimensional version of interval arithmetic. We discuss a collection of geometric constructions based on the Minkowski product and on one of its natural generalizations, the quaternion action. We also will present some topological facts about these products, and discuss the applications of these constructions to computer aided geometric design.
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Yepes, Nicolás Jesús. "Desigualdades de tipo Brunn-Minkowski y raíces de polinomios geométricos= From Brunn-Minkowski type inequalities to roots of geometric polynomials." Doctoral thesis, Universidad de Murcia, 2014. http://hdl.handle.net/10803/284792.
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La Tesis Doctoral está dedicada, por un lado, al estudio de desigualdades de tipo Brunn-Minkowski, especialmente cuando se trabaja con hipótesis sobre proyecciones/secciones, y, por otro lado, al estudio de las raíces de polinomios geométricos que surgen de una generalización del denominado funcional de Wills. En medio, nos encontraríamos las salchichas, las cuales resultan ser, salvo cuerpos convexos degenerados, la familia de los ‘conjuntos extremales’ en relación a algunas mejoras lineales de desigualdades tales como la desigualdad de Brunn-Minkowski o la primera desigualdad de Minkowski (y por tanto también de las desigualdades isoperimétrica y de Uryshon). Además esta familia de cuerpos convexos está ampliamente relacionada con algunos problemas relativos al polinomio de Steiner. Comenzamos estableciendo las nociones básicas que se necesitarán en un desarrollo posterior. A continuación, estudiamos mejoras de la desigualdad de Brunn-Minkowski, en el sentido de ‘refinar’ el exponente 1/n, cuando se asume que los cuerpos comparten una proyección común sobre un (n-k)-plano, por un lado, y para familias de cuerpos particulares, por el otro. En el tercer capítulo, abordamos el caso de igualdad en la versión lineal de la desigualdad de Brunn-Minkowski; nuestro enfoque subyace en (el estudio de) una posible caracterización de la linealidad del volumen a través de salchichas. En el último capítulo, investigamos las raíces de una familia de polinomios geométricos de cuerpos convexos asociados a una medida dada en la semirrecta real no-negativa, que surgen de una generalización natural del funcional de Wills.The Doctoral Dissertation is devoted, on the one hand, to the study of Brunn-Minkowski's type inequalities, especially when working with projections/sections assumptions, and, on the other hand, to the study of the roots of geometric polynomials which arise from a generalization of the so-called Wills functional. In the middle, we would find sausages, which turn out to be, up to degenerated convex bodies, the family of ‘extremal sets’ in relation to some linear improvements of inequalities such as Brunn-Minkowski's inequality or Minkowski's first inequality (and thus also the isoperimetric and Urysohn's inequalities). Furthermore, this family of convex bodies is strongly connected to some problems relative to the Steiner polynomial. We start establishing the basic notions that will be needed further on. Next, we study refinements of the Brunn-Minkowski inequality, in the sense of ‘enhancing’ the exponent 1/n, when assuming that the bodies share a common projection onto an (n-k)-plane on the one hand, and for particular families of bodies on the other hand. In the third chapter, we deal with the equality case in the linear version of Brunn-Minkowski’s inequality; our approach relies on (the study of) a possible characterization of the linearity of the volume through sausages. In the last chapter, we investigate the roots of a family of geometric polynomials of convex bodies associated to a given measure on the non-negative real line, which arise from a natural generalization of the Wills functional.
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Berchtold, Maik. "Modelling of random porous media using Minkowski-functionals /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17549.
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Averkov, Gennadiy. "Metrical Properties of Convex Bodies in Minkowski Spaces." Doctoral thesis, Universitätsbibliothek Chemnitz, 2004. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200401537.
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The objective of this dissertation is the application of Minkowskian cross-section measures (i.e., section and projection measures in finite-dimensional linear normed spaces over the real field) to various topics of geometric convexity in Minkowski spaces, such as bodies of constant Minkowskian width, Minkowskian geometry of simplices, geometric inequalities and the corresponding optimization problems for convex bodies. First we examine one-dimensional Minkowskian cross-section measures deriving (in a unified manner) various properties of these measures. Some of these properties are extensions of the corresponding Euclidean properties, while others are purely Minkowskian. Further on, we discover some new results on the geometry of a simplex in Minkowski spaces, involving descriptions of the so-called tangent Minkowskian balls and of simplices with equal Minkowskian heights. We also give some (characteristic) properties of bodies of constant width in Minkowski planes and in higher dimensional Minkowski spaces. This part of investigation has relations to the well known \emph{Borsuk problem} from the combinatorial geometry and to the widely used monotonicity lemma from the theory of Minkowski spaces. Finally, we study bodies of given Minkowskian thickness ($=$ minimal width) having least possible volume. In the planar case a complete description of this class of bodies is given, while in case of arbitrary dimension sharp estimates for the coefficient in the corresponding geometric inequality are foundDie Dissertation befasst sich mit Problemen fuer spezielle konvexe Koerper in Minkowski-Raeumen (d.h. in endlich-dimensionalen Banach-Raeumen). Es wurden Klassen der Koerper mit verschiedenen metrischen Eigenschaften betrachtet (z.B., Koerper konstante Breite, reduzierte Koerper, Simplexe mit Inhaltsgleichen Facetten usw.) und einige kennzeichnende und andere Eigenschaften fuer diese Klassen herleitet
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Shonoda, Emad N. Naseem. "On Ruled Surfaces in three-dimensional Minkowski Space." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-63555.
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In a Minkowski three dimensional space, whose metric is based on a strictly convex and centrally symmetric unit ball , we deal with ruled surfaces Φ in the sense of E. Kruppa. This means that we have to look for Minkowski analogues of the classical differential invariants of ruled surfaces in a Euclidean space. Here, at first – after an introduction to concepts of a Minkowski space, like semi-orthogonalities and a semi-inner-product based on the so-called cosine-Minkowski function - we construct an orthogonal 3D moving frame using Birkhoff’s left-orthogonality. This moving frame is canonically connected to ruled surfaces: beginning with the generator direction and the asymptotic plane of this generator g we complete this flag to a frame using the left-orthogonality defined by ; ( is described either by its supporting function or a parameter representation). The plane left-orthogonal to the asymptotic plane through generator g(t) is called Minkowski central plane and touches Φ in the striction point s(t) of g(t). Thus the moving frame defines the Minkowski striction curve S of the considered ruled surface Φ similar to the Euclidean case. The coefficients occurring in the Minkowski analogues to Frenet-Serret formulae of the moving frame of Φ in a Minkowski space are called “M-curvatures” and “M-torsions”. Here we essentially make use of the semi-inner product and the sine-Minkowski and cosine-Minkowski functions. Furthermore we define a covariant differentiation in a Minkowski 3-space using a new vector called “deformation vector” and locally measuring the deviation of the Minkowski space from a Euclidean space. With this covariant differentiation it is possible to declare an “M-geodesicc parallelity” and to show that the vector field of the generators of a skew ruled surface Φ is an M-geodesic parallel field along its Minkowski striction curve s. Finally we also define the Pirondini set of ruled surfaces to a given surface Φ. The surfaces of such a set have the M-striction curve and the strip of M-central planes in common
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Keil, Werner H. "Perturbative finite temperature field theory in Minkowski space." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/29127.
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This thesis contains a perturbative analysis of decay and scattering rates in finite temperature and density environments. The discussion is based on the Niemi-Semenoff real-time formulation of quantum field theory at finite temperature. Two systems are investigated: neutron β decay at finite density, and Higgs boson decay with radiative QED corrections, at finite temperature.
For neutron β decay, a fully relativistic analysis at tree level is presented. An analytic formula for the free neutron decay rate is derived, and subsequently generalized to a finite-density environment. The decay rates are obtained from the imaginary part of the neutron self-energy. This method turns out to be very straightforward and elegant, since it includes all relevant decay and inverse decay modes in a nontrivial way.
The decay of a Higgs boson into two fermions, with one-loop QED corrections, is used to discuss the problem of renormalization at finite temperature. It is found that the finite-temperature part of the self-energy corrections cannot be absorbed into temperature dependent mass and wave function renormalization counterterms, due to the lack of Lorentz invariance, and it is argued that finite-temperature renormalization is not an appropriate concept for decay and scattering rate calculations. A general algorithm for the calculation of thermal self-energy corrections is derived, and applied to the Higgs-fermion system. The result is explicitly shown to be free of infrared and mass singularities. Previous work on the subject is compared to this general approach, and possible applications in cosmology and astrophysics are discussed.Science, Faculty of
Physics and Astronomy, Department of
Graduate
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Saloom, Amani Hussain. "Curves in the Minkowski plane and Lorentzian surfaces." Thesis, Durham University, 2012. http://etheses.dur.ac.uk/4451/.
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We investigate in this thesis the generic properties of curves in the Minkowski plane R2 1 and of smooth Lorentzian surfaces. The generic properties of curves in R2 1 are obtained by studying the contacts of curves in R2 1 with lines and pseudo-circles. These contacts are captured by the singularities of the families of height and distancesquared functions on the curves. On the other hand, the generic properties of smooth Lorentzian surfaces are obtained by studying certain Binary Differential Equations defined on the surfaces.
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Alkauskas, Giedrius. "Integral transforms of the Minkowski question mark function." Thesis, University of Nottingham, 2008. http://eprints.nottingham.ac.uk/10641/.
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The Minkowski question mark function F(x) arises as a real distribution function of rationals in the Farey (alias, Stern-Brocot or Calkin-Wilf) tree. In this thesis we introduce its three natural integral transforms: the dyadic period function G(z), defined in the cut plane; the dyadic zeta function zeta_M(s), which is an entire function; the characteristic function m(t), which is an entire function as well. Each of them is a unique object, and is characterized by regularity properties and a functional equation, which reformulates in its own terms the functional equation for F(x). We study the interrelations among these three objects and F(x). It appears that the theory is completely parallel to the one for Maass wave forms for PSL_2(Z). One of the main purposes of this thesis is to clarify the nature of moments of the Minkowski question mark function.
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Trezzi, Elisabetta. "Minkowski lP norms in estimating the scene illuminant." Thesis, University of East Anglia, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.445208.
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SOUZA, Danillo Flugge de. "Superfícies Helicoidais no espaço Euclidiano e de Minkowski." Universidade Federal de Goiás, 2012. http://repositorio.bc.ufg.br/tede/handle/tde/1958.
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Previous issue date: 2012-05-31In this work, based in [2] and [6] we studies helicoidal surfaces of the Euclidean space and Minkowski space R31 with prescribed Gaussian or mean curvature given by smooth functions. In the Minkowski space we consider three especial kinds of helicoidal surfaces, corresponding to the space-like, time-like or light-like axes of revolution and show some geometric meanings of the helicoidal surfaces of the space-like type. We also define certain solinoid (tubular) surfaces around a hyperbolic helix in R31and we study some of their geometric properties.
Neste trabalho, baseado nos artigos [2] e [6] estudamos superfícies helicoidais no Espaço Euclidiano e no Espaço de Minkowski R31 com curvatura média ou Gaussiana dada por funções diferenciáveis. No Espaço de Minkowski R31 , consideramos três tipos especiais de superfícies helicoidais, correspondendo aos eixos de revolução space-like, time-like ou light-like e apresentamos alguns significados geométricos de superfícies helicoidais do tipo space-like. Também definimos superfícies (tubulares) solenóides em torno de uma hélice hiperbólica em R31 e estudamos algumas de suas propriedades geométricas.
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Gutiérrez, Gómez Cristian Leonardo [UNESP]. "Minkowski space Bethe-Salpeter equation within Nakanishi representation." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/144735.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O trabalho apresentado nessa tese foi dedicado em explorar soluções de estado ligado para a equação de Bethe-Salpeter, obtidas diretamente no espaço de Minkowski. Para isso, consideramos um procedimento que combina a representação integral de Nakanishi para a amplitude Bethe-Salpeter, desenvolvido por N. Nakanishi na década de sessenta, em conjunto com a projeção da amplitude de Bethe-Salpeter no plano nulo, também conhecida como a projeção na frente de luz. Este método, além de permitir calcular as energias de ligação, que são acessíveis a partir de cálculos bem conhecidos no espaço Euclidiano, permite que se obtenha a amplitude Bethe-Salpeter no espaço de Minkowski e a função de onda de valência na frente de luz. A verificação da validade desse procedimento foi confirmada através de comparação da amplitude de Bethe-Salpeter obtida diretamente no espaço Euclidiano com a amplitude correspondente derivada da equação de Bethe-Salpeter, usando a representação integral de Nakanishi, uma vez a rotação de Wick é realizada. O sucesso dessa abordagem, quando aplicado ao problema do estado ligado de duas partículas escalares trocando uma outra partícula escalar no estado fundamental, assim como o estudo correspondente no limite de energia zero, nos motivou a ampliar a aplicação do procedimento para o estudo de outros problemas de interesse. Em particular, o método foi estendido para o estudo de sistemas com duas dimensões espaciais e uma temporal (2+1), considerando o interesse crescente que surgiu em Física da matéria condensada, onde podemos destacar o caso de elétrons de Dirac no grafeno. Nessa análise preliminar, nos restringimos ao modelo escalar que nos permitiu acessar as principais dificuldades que deverão ser enfrentadas ao estudar o problema do estado ligado entre dois férmions. Dessa forma, este tratamento pode ser considerado como um primeiro passo para a implementação de um método mais realístico em um problema fermiônico. Os cálculos anteriores que consideramos em nossos estudos foram realizados através da aproximação de escada para o kernel de interação irredutível para os estados de onda-s. Portanto, uma das extensões que exploramos nesta tese foi o efeito de se introduzir a contribuição de ordem seguinte no kernel de interação, conhecida como a contribuição de escada-cruzada (cross-ladder). Os efeitos nas energias de ligação e na função de onda na frente de luz é foram analisados de forma detalhada, através dos resultados apresentados. Um estudo particularmente interessante, que foi extensivamente estudado nesta tese, se refere ao problema do espectro da equação Bethe-Salpeter para o estado ligado escalar-escalar. O espectro de estados excitados foi obtido com a abordagem da representação integral Nakanishi, sendo comparado com o obtido no espaço Euclidiano. Além disso, as raçoes excitado/fundamental do espectro relativístico foram reduzidas para às não-relativístico através da escolha de energias de ligação pequenas e considerando a massa do bóson trocado sendo próxima de zero. A função de onda de valência na frente de luz e a função de onda no parâmetro de impacto são apresentadas mostrando as principais características dos estados excitados conhecidos da estrutura não relativística. Na análise do espectro, também são estudadas as amplitudes de momentum-transverso para o estado fundamental e o primeiro estado excitado, que podem ser obtidos, de forma equivalente, no espaço de Minkowski assim como no espaço Euclidiano. Finalmente, focamos o estudo nos fatores de forma eletromagnéticos elásticos na abordagem da Bethe-Salpeter. Consciente de que o cálculo correto dos fatores de forma deve ser feito no espaço de Minkowski, o fator de forma elástico foi calculado levando-se em consideração a aproximação de impulso padrão. Além disso, foi também estudado o efeito da contribuição de ordem superior no fator de forma.
The work presented in this thesis was dedicated in exploring bound-state solutions of the Bethe-Salpeter equation directly in the Minkowski space. For that, we consider a method that combines the Nakanishi integral representation for the Bethe-Salpeter amplitude, developed by Noboru Nakanishi in the sixties, together with the projection of the Bethe-Salpeter amplitude onto the null-plane, also known as the light-front projection. This approach, besides of allowing to compute the binding energies, which are accessible from the usual Euclidean calculation, enables to obtain the Bethe-Salpeter amplitude in the Minkowski space and the light-front wave function. The feasibility of such an approach is further verified by comparing the Bethe-Salpeter amplitude obtained directly in the Euclidean space with the corresponding amplitude obtained by solving the Bethe-Salpeter equation, using the Nakanishi integral representation, once the Wick rotation is performed to this latter. The success of the approach when applied to study the bound state problem of two-scalar particles exchanging another scalar particle in the ground state, as well as the corresponding study at the zero-energy limit, has encouraged us to extend this method to another interesting problems. In particular, we start by extending the method to study problems in (2+1) dimensions due to the increasing interest in the condensed-matter physics, like the study of Dirac electrons in graphene. In this initial examination we restrict to the scalar model, which enables us to access to the main difficulties that we will face when studying the fermion-fermion bound state problem. Hence, this calculation can be considered as the first step towards the implementation of the method to real fermionic problems. The previous calculations have been performed by considering the ladder approximation for the irreducible interacting kernel for s-wave states. Therefore, one of the extensions that is explored in this thesis is the effect of introducing the next contribution in the interacting kernel, known as the scalar-scalar cross-ladder contribution. The effects in the eigenvalues and the light-front wave functions are analyzed in detail, by considering the computed results. A particular interesting subject, extensively studied in this thesis, is concerned to the spectrum of the Bethe-Salpeter equation for the scalar-scalar bound-state problem. The spectrum of excited states obtained with the Nakanishi integral representation approach is compared with that obtained in the Euclidean calculation. Besides, the ratio energies excited/ground of the relativistic spectrum is reduced to the non-relativistic one by choosing small binding energies and the mass of the exchanged boson approaching to zero. The valence light-front wave function and the impact-parameter space valence wave function are displayed, revealing the main features of excited states known from the non-relativistic framework. In the analysis of the spectrum, we also studied the transverse-momentum amplitudes for the ground and first-excited state, which can be equivalently obtained in the Minkowski or Euclidean spaces. Finally, we focus on the study of electromagnetic elastic form factors within the Bethe-Salpeter approach. Aware that the correct calculation of form factors should be performed in the Minkowski space, the calculation of the elastic form factor is carried out with the standard impulse approximation and in addition the effect of the next contribution to the form factor is studied.
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Gutiérrez, Gómez Cristian Leonardo. "Minkowski space Bethe-Salpeter equation within Nakanishi representation /." São Paulo, 2016. http://hdl.handle.net/11449/144735.
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Orientador: Lauro TomioCoorientador: Tobias Frederico
Banca: Vladimir Karmanov
Banca: Kazuo Tsushima
Banca: Alfredo Takashi Suzuki
Banca: Waynei Leonardo da Silva de Paula
Resumo: O trabalho apresentado nessa tese foi dedicado em explorar soluções de estado ligado para aequação de Bethe-Salpeter, obtidas diretamente no espaço de Minkowski. Para isso, consideramos um procedimento que combina a representação integral de Nakanishi para a amplitude Bethe-Salpeter, desenvolvido por N. Nakanishi na década de sessenta, em conjunto com a projeção da amplitude de Bethe-Salpeter no plano nulo, também conhecida como a projeção na frente de luz. Este método, além de permitir calcular as energias de ligação, que são acessíveis a partir de cálculos bem conhecidos no espaço Euclidiano, permite que se obtenha a amplitude Bethe-Salpeter no espaço de Minkowski e a função de onda de valência na frente de luz. A verificação da validade desse procedimento foi confirmada através de comparação da amplitude de Bethe-Salpeter obtida diretamente no espaço Euclidiano com a amplitude correspondente derivada da equação de Bethe-Salpeter, usando a representação integral de Nakanishi, uma vez a rotação de Wick é realizada. O sucesso dessa abordagem, quando aplicado ao problema do estado ligado de duas partículas escalares trocando uma outra partícula escalar no estado fundamental, assim como o estudo correspondente no limite de energia zero, nos motivou a ampliar a aplicação do procedimento para o estudo de outros problemas de interesse. Em particular, o método foi estendido para o estudo de sistemas com duas dimensões espaciais e uma temporal (2+1), considerando o interesse cresc... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The work presented in this thesis was dedicated in exploring bound-state solutions of the Bethe-Salpeter equation directly in the Minkowski space. For that, we consider a method that combines the Nakanishi integral representation for the Bethe-Salpeter amplitude, developed by Noboru Nakanishi in the sixties, together with the projection of the Bethe-Salpeter amplitude onto the null-plane, also known as the light-front projection. This approach, besides of allowing to compute the binding energies, which are accessible from the usual Euclidean calculation, enables to obtain the Bethe-Salpeter amplitude in the Minkowski space and the light-front wave function. The feasibility of such an approach is further verified by comparing the Bethe-Salpeter amplitude obtained directly in the Euclidean space with the corresponding amplitude obtained by solving the Bethe-Salpeter equation, using the Nakanishi integral representation, once the Wick rotation is performed to this latter. The success of the approach when applied to study the bound state problem of two-scalar particles exchanging another scalar particle in the ground state, as well as the corresponding study at the zero-energy limit, has encouraged us to extend this method to another interesting problems. In particular, we start by extending the method to study problems in (2+1) dimensions due to the increasing interest in the condensed-matter physics, like the study of Dirac electrons in graphene. In this initial examination we restrict to the scalar model, which enables us to access to the main difficulties that we will face when studying the fermion-fermion bound state problem. Hence, this calculation can be considered as the first step towards the implementation of the method to real fermionic problems. The previous calculations have been performed by considering the ladder approximation for the... (Complete abstract click electronic access below)
Doutor
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SILVA, Patrício José Félix da. "Referenciais não-inerciais no Espaço-Tempo de Minkowski." Universidade Federal de Campina Grande, 2009. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1453.
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CNPq
Capes
Um sistema de coordenadas tem a função de localizar os eventos do espaço-tempo com respeito a um sistema de referência. A construção do sistema de coordenadas depende crucialmente da noção de simultaneidade associada ao referencial. No entanto, não existe uma maneira natural, ou privilegiada, de definir simultaneidade para referenciais não inerciais, mesmo no espaço-tempo de Minkowski. Cada procedimento conduz a diferentes sistemas de coordenadas. Neste trabalho, discutimos alguns métodos bem conhecidos da literatura especializada. Estudamos as coordenadas de Rindler, de Fermi-Walker, as coordenadas de Radar e as coordenadas de Emissão (ou GPS). O sistema de coordenadas de Rindler é um dos sistemas de grande destaque porque permite simular algumas propriedades da geometria do Buraco Negro num espaço-tempo plano. As coordenadas de Rindler estão associadas a uma família de observadores uniformemente acelerados que obedecem à relação a=1/ρ, onde a é a aceleração própria do observador e ρ a sua posição inicial com respeito a algum sistema de referência inercial. Neste trabalho, propomos um método para construção de sistemas de coordenadas adaptados a observadores cuja a celeração depende da posição inicial segundo a regra a=a0/ρn, onde n ∈ N e a0 é uma constante, usando o princípio da localidade. O caso n = 1 recupera as coordenadas de Rindler. Os outros casos nos permitem discutir a relação entre a geometria não-Euclidiana das secções espaciais e referenciais acelerados,como originariamente proposto por Einstein. Além disso, com a generalização podemos simular o comportamento de observadores estáticos tanto nas proximidades do horizonte de um Buraco Negro (n=1) quanto em regiões afastadas (n=2).
The main role of a coordinate systein is to localize the event-s of spacetime with respect to a frame of reference. The construetion of a coordinate systein depeuds crucially on the notíon of simultaneity associated to the frame of reference. However, there is no natural manner of defining simultaneity adapted to non-inertial frames of reference, even in the case of Minkowski spacetime. Each procedure leads to different coordinate systems. In thls work. we discuss some well-known methods found in the Literatura. We study the Rindler coordinates. Fermi-Walker coordinates. Radar coodinadates and Emission (or GPS) coordinates. The system of Rindler coordinates has great interest because it simulates in a flat spacetime some aspects of a Black Hole's geometry. We can say that Rindler coordinates are adapted to a family of uniformly accelerated observeis which obey the relatiou a = i, where a is the proper acceieration and p is the initial position with respect to some inertial system. In this work, we also propose a method in order to construct coordinate systems adapted to observers whose accelerations depend on the initial position according to the formula a = where n e N and a» is a constant, by using the locality principie. The case TI = 1 reproduces the Rindler coordinates. The other cases allow us to verify a connection between non-Euciideaii geometry of the spatial sections and non-inertial frames of reference, as it was originally suggested by Einstein. With this generalization we can also simulate the behavior of static observers in the vicinity of a Black Hole"s Horizon (TI = 1) and also in distant regions (n - 2)
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Furlan, Manuel. "The Minkowski and conformal spaces as homogeneous spaces." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
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Lo scopo principale di questa tesi è quello di studiare lo spazio-tempo di Minkowski come spazio omogeneo. In altre parole, vogliamo vedere tale spazio come spazio omogeneo per un gruppo di simmetria, prima, per il gruppo di Lorentz e poi più in generale per il gruppo di Poincaré.
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Wu, Senlin. "Geometry of Minkowski Planes and Spaces -- Selected Topics." Doctoral thesis, [S.l. : s.n.], 2009. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200900226.
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Sushkoff, Kira. "Minkowski Actions of Quaternion Sets and their Applications." Scholarship @ Claremont, 2003. https://scholarship.claremont.edu/hmc_theses/156.
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Applications of Laguerre geometry to computer aided geometric design are presented, realized through Minkowski actions. Basic Laguerre geometry is first discussed. Then quaternions, set multiplication, and the use of quaternion sets to define Minkowski actions are described and used to achieve results used in geometric design.
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Müller, Oliver. "Numerik für Minimalflächen im Minkowskiraum." [S.l. : s.n.], 2003. http://www.freidok.uni-freiburg.de/volltexte/764.
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FERNANDES, Marco Antônio do Couto. "Conjectura de Carathéodory para Superfícies em 3-espaço Minkowski." reponame:Repositório Institucional da UNIFEI, 2017. http://repositorio.unifei.edu.br:8080/xmlui/handle/123456789/685.
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O objetivo deste trabalho é o estudo da conjectura de Carathéodory adaptada para o espaço de Minkowski, ℝ³₁. A conjectura de Carathéodory é ainda hoje um problema em aberto no espaço Euclidiano e se enuncia da seguinte forma “Toda superfície fechada e convexa possui no mínimo 2 pontos umbílicos”, onde uma superfícies fechada é uma superfície compacta e sem bordo. Farid Tari demonstrou esta conjectura para superfícies em ℝ³₁. Para tanto, realizamos um estudo sobre equações diferenciais binárias da forma a(x,y)dy² + 2b(x; y)dxdy + c(x; y)dx² = 0, quando σ = b² – ac possui uma singularidade de Morse na origem, e também um estudo sobre as linhas de curvatura de superfícies em ℝ³ e ℝ³₁.
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Papuico, Bernardo Victor Johnny. "Sobre el álgebra geométrica del espacio-tiempo de Minkowski." Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2012. https://hdl.handle.net/20.500.12672/4729.
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En este trabajo presentamos AG(4, 1), el álgebra geométrica del espacio-tiempo de Minkowski R4,1, adaptando el caso euclidiano tridimensional. En este contexto AG(4, 1) contiene una subálgebra, AG(4, 1)+, isomorfa a AG(3), y esto permite obtener varios resultados interesantes. Palabras claves: PRODUCTO GEOMÉTRICO, ÁLGEBRA GEOMÉTRICA, ESPACIO-TIEMPO DE MINKOWSKI, SUBÁLGEBRA PAR.--- This work introduce AG(4, 1), the geometric algebra of Minkowski space-time R 4,1 , adapting the euclidean three dimensional case. In this context AG(4, 1) contain a subalgebra, AG(4, 1)+, isomorphic to AG(3), and this permit to obtain many interesting resoults. Key words: GEOMETRIC PRODUCT, GEOMETRIC ALGEBRA, MINKOWSKI SPACE-TIME, EVEN SUBÁLGEBRA
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Tola, Pasquel José. "Espacios seudoeuclideanos, Espacios de Minkowski y Transformaciones de Lorentz." Pontificia Universidad Católica del Perú, 2013. http://repositorio.pucp.edu.pe/index/handle/123456789/96015.
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Esta nota trata acerca de los espacios vectoriales sobre el campo de los números reales, asociados a formas cuadráticas no degeneradas, es decir acerca de los espacios cuadráticos repulares; y tiene, además, el propósito de mostrar cómo dichos espacios tienen aplicación en la teoría especial de la relatividad, razón por la cual la nomenclatura se inspira en esa aplicación. Así, por ejemplo, se llama aquí vectores lumínicos a los que, en contexto estrictamente algebraico se denomina vectores isotrópicos.
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Hoehner, Steven D. "The Hasse-Minkowski Theorem in Two and Three Variables." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338317481.
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Eisenschmidt, Elke. "Integer Minkowski programs and an application in network design." Tönning Lübeck Marburg Der Andere Verl, 2009. http://d-nb.info/998007692/04.
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Barki, Hichem. "Analyse de maillages 3D par morphologie mathématique." Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10226.
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La morphologie mathématique est une théorie puissante pour l’analyse d’images 2 D. Elle se base sur la dilatation et l’érosion, qui correspondent à l’addition et la soustraction de Minkowski. Afin d’analyser des maillages 3D par morphologie mathématique, on doit disposer d’algorithmes performants et robustes pour le calcul exact de l’addition et de la soustraction pour ces maillages. Malheureusement, les travaux existants sont, soit approximés, soit non robustes ou limités par des contraintes. Aucun travail n’a traité la différence. Ces difficultés sont dues au fait qu’un maillage représente une surface linéaire par morceaux englobant un ensemble contenu et non dénombrable. Nous avons introduit la notion de sommets contributeurs et nous avons développé un algorithme efficace et robuste pour le calcul de la somme de polyèdres convexes. Nous l’avons par la suite adapté et proposé deux algorithmes performants pour la somme d’une paire de polyèdres non convexe/convexe, tout en gérant correctement les polyèdres complexes, les situations de non-variété ainsi que les changements topologiques. Nous avons également démontré la dualité des sommets contributeurs et nous l’avons exploité pour développer la première approche du calcul exact et efficace de la différence de polyèdres convexes. La dualité des sommets contributeurs ainsi que la robustesse et l’efficacité de nos approches motivent le développement d’une approche unifiée pour l’addition et la soustraction de polyèdres quelconques, ce qui permettra d’appliquer des traitements morphologiques à des maillages 3D. D’autres domaines tels que l’imagerie médicale, la robotique, la géométrie ou la chimie pourront en tirer profitMathematical morphology is a powerful theory for the analysis of 2D digital images. It is based on dilation and erosion, which correspond to Minkowski addition and subtraction. To be able to analyze 3D meshes using mathematical morphology, we must use efficient and robust algorithms for the exact computation of the addition and subtraction of meshes. Unfortunately, existing approaches are approximated, non-robust or limited by some constraints. No work has addressed the difference. These difficulties come from the the fact that a mesh represents a piecewise linear surface bounding a continuous and uncountable set. We introduced the concept of contributing vertices and developed an efficient and robust algorithm for the computation of the Minkowski sum of convex polyhedra. After that, we adapted and proposed two efficient algorithms for the computation of the Minkowski sum of a non-convex/convex pair of polyhedra, while properly handling complex polyhedra, non-manifold situations and topological changes. We also demonstrated the duality of the contributing vertices concept and exploited it to develop the first approach for the efficient and exact computation of the Minkowski difference of convex polyhedra. The duality of the contributing vertices concept as well as the robustness and efficiency of our approaches motivate the development of a unified approach for the Minkowski addition and subtraction of arbitrary polyhedral, which will permit the morphological analysis of 3D meshes. Other areas such as medical imaging, robotics, geometry or chemistry may benefit from our approaches
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Alves, Filipe Kelmer. "Transformações de Backlund no espaço-tempo de Minkowski 3-dimensional." reponame:Repositório Institucional da UnB, 2017. http://repositorio.unb.br/handle/10482/23221.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Matemática, 2017.Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2017-03-15T19:13:23Z No. of bitstreams: 1 2017_FilipeKelmerAlves.pdf: 1271841 bytes, checksum: 6c82110fc4366084dfa12e4a17b31ae5 (MD5)
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Nesta dissertação discutiremos sobre Transformações de Bäcklund entre superfícies no espaço-tempo de Minkowski. Apresentaremos a versão clássica da Transformação de Bäcklund no Espaço Euclidiano e vamos generalizá-la para o Espaço de Minkowski e analisar suas propriedades. Mostraremos que existem análogos, no Espaço de Minkowski do Teorema de Bäcklund, Teorema de Integrabilidade, relações entre superfícies e soluções de equações diferenciais parciais e existência de família das soluções.
In this work we shall discuss about Bäcklund's Transformation in Minkowski Space-Time. Our main goal is to establish, in Minkowski Space, the Euclidian classical results such as Bäcklund's Theorem, Integrability Conditions and their relation between existence of surfaces related to Partial Differential Equations solutions.
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Gomez, Gomez Jhon Elver. "Superficies de curvatura media constante en el espacio de Minkowski." Master's thesis, Pontificia Universidad Católica del Perú, 2019. http://hdl.handle.net/20.500.12404/15628.
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El trabajo trata sobre encontrar una representación para superficies espaciales inmersas en L3 con curvatura media constante y con métrica de Lorentz. Basado en el paper [1], esto conlleva a estudiar la aplicación de Gauss, la ecuación de Beltrami y la fórmula de representación para la superficie espaciales inmersa en L3, en función de la aplicación de Gauss y la curvatura media de la superficie. Entre otros, se ha utilizado principalmente las bibliografías [2], [3], [7], [13], [14].Tesis
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Fernandes, Luiz Carlos. "Desigualdades de Sobolev euclidianas ótimas via desigualdade de Brunn-Minkowski." Universidade Federal de Minas Gerais, 2010. http://hdl.handle.net/1843/EABA-8AEMEC.
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Apresentaremos neste trabalho a estraégia proposta em [4] com os detalhes necessários a uma boa compreensão. Esta dissertação está dividida da seguinte maneira: no Capítulo 2, são apresentados três resultados importantes que serão aplicados na demonstração da desigualdade de Sobolev ótima e também suas respectivas demonstrações. Na seção 2.1, provamos a desigualdade de Brunn-Minkowki, na seção 2.2, demonstramos o teorema de Prékopa-Leindler, que deriva diretamente de (1.5) e, na seção 2.3, apresentamos um estudo sucinto da equação de Hamilton-Jacobi. No
Capítulo 3, demonstramos o resultado principal deste trabalho, explicitando os pontos em que são utilizadas as ferramentas do capítulo 2. Há ainda um apêndice destinado à prova de algumas desigualdades elementares que serão necessárias na demonstração e outro em que demonstramos a desigualdade de Sobolev clássica (1.1).
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Jia, Shaoyang. "Formulating Schwinger-Dyson Equations for Qed Propagators in Minkowski Space." W&M ScholarWorks, 2017. https://scholarworks.wm.edu/etd/1516639559.
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The Schwinger-Dyson equations (SDEs) are coupled integral equations for the Green's functions of a quantum field theory (QFT). The SDE approach is the analytic nonperturbative method for solving strongly coupled QFTs. When applied to QCD, this approach, also based on first principles, is the analytic alternative to lattice QCD. However, the SDEs for the n-point Green's functions involves (n+1)-point Green's functions (sometimes (n+2)-point functions as well). Therefore any practical method for solving this infinitely coupled system of equations requires a truncation scheme. When considering strongly coupled QED as a modeling of QCD, naive truncation schemes violate various principles of the gauge theory. These principles include gauge invariance, gauge covariance, and multiplicative renormalizability. The combination of dimensional regularization with the spectral representation of propagators results in a tractable formulation of a truncation scheme for the SDEs of QED propagators, which has the potential to preserve the aforementioned principles and renders solutions obtainable in the Minkowski space. This truncation scheme is the main result of this dissertation.
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Ait, Haddou Rachid. "Courbes à Hodographe Pythagorien en Géométrie de Minkowski et Modélisation Géométrique." Phd thesis, Université Joseph Fourier (Grenoble), 1996. http://tel.archives-ouvertes.fr/tel-00345362.
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La construction des courbes parallèles est fondamentale pour différentes applications en modélisation géométrique, telles que l'étude des trajectoires d'outils pour les machines à commande numérique ou pour la définition des zones de tolérance. En général, la courbe parallèle d'une courbe rationnelle n'est pas rationnelle, ce qui conduit à déterminer une approximation de cette courbe parallèle par une courbe spline. Récemment, J. C. Fiorot et T. Gensane et indépendamment H. Pottmann ont donné la forme générale de toutes les courbes rationnelles à parallèles rationnelles (courbes à hodographe pythagorien). Dans cette dernière famille figurent les quartiques de Tschirnhausen. Ces courbes ont même flexibilité que les coniques, leurs courbes parallèles sont rationnelles de degré quatre et sont exactement les développantes des cubiques de Tschirnhausen. En se basant sur cette caractérisation, nous présentons un algorithme d'approximation, avec un contact d'ordre deux, d'une courbe et de ses parallèles par des quartiques de Tschirnhausen préservant la variation de la courbure. Par ailleurs, le caractère judicieux de la représentation Bézier duale des courbes à hodographe pythagorien et de leurs parallèles, nous a permis de construire des ovales et des rosettes rationnelles à largeur constante qui jouent un rôle important en mécanique des cames. Enfin, suite aux travaux de H. Busemann et H. Guggenheimer sur la géométrie plane de Minkowski, nous généralisons la notion de courbes parallèles ainsi que les résultats de H. Pottmann (concernant la caractérisation Bézier duale et la caractérisation géométrique des courbes à hodographe pythagorien) au plan de Minkowski
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Dutriaux, Antoine. "Analyse et modèles dynamiques non commutatifs sur l'espace de q-Minkowski." Phd thesis, Université de Valenciennes et du Hainaut-Cambresis, 2008. http://tel.archives-ouvertes.fr/tel-00289899.
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Cette thèse se place dans le cadre du vaste domaine s'intitulant géométrie non commutative, domaine dont l'étude est motivée par l'opinion courante des mathématiciens et physiciens selon laquelle les méthodes de la géométrie non commutative peuvent être utiles pour décrire certains processus dynamiques à l'échelle de Planck. Aussi l'objectif principal de cette thèse est de généraliser quelques modèles dynamiques définis sur l'espace de Minkowski sur son q-analogue. Des tentatives d'introduire des modèles dynamiques qui seraient covariants par rapport à l'action de groupes quantiques ont été entrepris juste après la création de la théorie sur les groupes quantiques par Drinfeld. Les modèles les plus intéressants sont ceux qui sont liés au q-analogue de l'espace de Minkowski. C'est P. Kulish qui définit cette algèbre comme étant un cas particulier d'une algèbre appelée modified Reflection Equation Algebra (mREA) elle-même liée à un opérateur appelé symétrie de Hecke. Nous définissons donc certains modèles dynamiques qui sont des déformations de modèles classiques, l'espace des phases de nos modèles déformés n'est autre alors que notre espace de q-Minkowski. Nous recherchons par la suite des intégrales de mouvement de ces dynamiques, ce qui nous amène à définir des analogues de l'énergie et du vecteur de Runge-Lenz. Nous généralisons pour terminer les équations aux dérivées partielles de la théorie des champs et en particulier l'opérateur de Maxwell.