Dissertations / Theses on the topic 'Monopoles'
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Nouri-Zonoz, Mohammad. "Gravomagnetic monopoles." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624957.
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Hawksley, Ruth. "Hyperbolic monopoles." Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/14019.
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A Euclidean SU(2) monopole consists of a connection and Higgs field on an SU(2) bundle over π3, satisfying certain partial differential equations. Monopoles may equivalently be described in terms of holomorphic vector bundles on twistor space, algebraic curves in twistor space, rational maps, or solutions to Nahm's equations (a set of ODEs for matrix-valued functions), all satisfying some further conditions. Research by Atiyah, Donaldson, Hitchin, Nahm and others has provided a beautiful and relatively complete picture of these different viewpoints and the links between them. Monopoles have also been studied on hyperbolic space π3, although the corresponding picture in this case is less well understood. One difficulty is that the conditions which must be imposed in order for all the various correspondences to be valid have not yet been completely determined. A partial answer is given in Chapter 2, where it is proved that any hyperbolic monopole arising from a spectral curve satisfies a certain natural boundary condition. The proof uses the algebraic geometry of the spectral curve and is similar to Hurtubise's proof of the analogous result in the Euclidean case. A large part of this thesis concentrates on the "Braam-Austin" description of hyperbolic monopoles. This is the hyperbolic version of Nahm's description of Euclidean monopoles; a monopole corresponds to a pair of discrete matrix-valued functions satisfying some difference equations. Euclidean monopoles appear as limits of hyperbolic monopoles as the curvature of π3 tends to zero. This "Euclidean limit" is described geometrically and is studied in terms of Braam-Austin data. Explicit conditions are given for such a sequence to have a subsequence converging to a Euclidean monopole. The result depends on a conjecture (§ 4.5) about properties of Braam-Austin monopole solutions.
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Maldonado, Rafael. "Periodic monopoles." Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10729/.
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This thesis discusses periodic one dimensional arrays of BPS monopoles. An approximation based on the spectral curve is shown to provide an increasingly accurate description of the monopole fields in the limit of large monopole size to period ratio. Away from this limit the periodic monopole is studied by means of the Nahm transform, which leads to a dual system of Hitchin equations on a cylinder. A combination of analytical and numerical techniques is used to study the spatial symmetries of the periodic 2-monopole and its moduli space. In particular, the asymptotic moduli space metric is determined from the Nahm data, and symmetric one parameter families of monopole scattering processes are identified through the core of the moduli space. These ideas are readily applicable to higher charge periodic monopoles.
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Pires, dos Santos Rodrigo. "Monopoles on R⁵." Thesis, University of Leeds, 2015. http://etheses.whiterose.ac.uk/12561/.
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This thesis is motived by the wish to understand the structure of the moduli space of monopoles on R^5. Our approach to define monopoles is twistorial and we start by developing the twistor theory of R^5, which is an analogue of the twistor theory for R^3 developed by Hitchin. Using this, we describe a Hitchin-Ward transform for R^5, giving monopoles for the group SU(2). In order for us to construct monopoles we make use of spectral curves. Then, using those spectral curves we find a new system of equations, analogue to the Nahm's equations. Lastly, we prove that the geometry of the moduli space of solutions to this Nahm's equations carries a 2-symplectic structure.
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López, Bara Fernando Ignacio. "Electrodynamics and phase transitions in materials with magnetic monopoles." Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/665231.
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El trabajo está dirigido a analizar dos aspectos que están intrínsecamente relacionados. El primero se refiere al estudio de los estados globales y característicos de las estructuras magnéticas de los compuestos denominados “spin-ices” y el segundo se analizan los comportamientos bajo interacción electromagnética en medios infinitos y en sistemas confinados.
La principal novedad de estos compuestos es la existencia de estados excitados globales a bajas temperaturas en los cuales surgen entidades estructurales que mimetizan el comportamiento de monopolos magnéticos. En la primera parte del trabajo, los estados excitados de baja temperatura son estudiados en compuestos del tipo (ETR)₂Ti₂ O₇, dónde ETR se refiere a uno de los diversos lantánidos, principalmente Dy₂Ti₂O₇ y Ho₂Ti₂O₇ . A temperaturas comprendidas entre 0.05K a 0.17K, hay una transición de fase con características similares a un condensado Bose-Einstein cuyos componentes individuales están constituidos por dipolos magnéticos (dos monopolos, una carga magnética positiva y la otra negativa conectados por la interacción Coulombiana y separados por una distancia equivalente a la altura de cada tetraedro de la estructura cristalina la cual es descrita en el texto). Al incrementar la temperatura, dichos dipolos se rompen formando un plasma magnético de cargas positivas y negativas libres o cuasi libres cuya estadística es del tipo Fermi-Dirac. Los procesos de transición termodinámica son descritos por modelos analíticos para estados excitados de baja energía y la descripción de las sucesivas transiciones de fase. Se han determinado los potenciales termodinámicos, calor específico y entropía con los cuales se pueden mostrar las posibles transiciones de fase que ocurren en estos compuestos.
En la segunda parte, se realiza un análisis de las ecuaciones de Maxwell modificadas, así como de la fuerza de Lorentz generalizada ante la presencia de estas cargas magnéticas. La solución de estas ecuaciones nos permite obtener resultados que podrían tener interés empírico con tal de detectar monopolos magnéticos en otros compuestos naturales. Se ha estudiado la propagación transversal electromagnética en estos materiales al añadir un intenso campo eléctrico externo que permite deducir la densidad de monopolos por unidad de volumen y la masa efectiva de los mismos.
Hemos deducido las soluciones de las ecuaciones duales de Maxwell en medios confinados con simetrías rectangular y cilíndrica. En dichos medios en fase de plasma magnético, se ha obtenido la ecuación no lineal del parámetro de orden del sistema. Las características y propiedades de las soluciones de las ecuaciones de Maxwell modificas han sido determinados en los modos TM, obteniendo la conductividad magnética como una función dependiente de la frecuencia (llamada Magnetricidad); susceptibilidad magnética, tanto como picos de absorción electromagnética, y otras variables como la frecuencia de precesión y la frecuencia característica del plasma o frecuencia del plasmón. El poder obtener dichas frecuencias no ha permitido determinar la masa específica de estas cuasi partículas, siendo básica esta magnitud física para determinar y justificar las propiedades de conducción.
El objetivo fundamental de esta parte ha sido poder realizar un análisis sistemático para detectar en otros materiales la presencia de posibles cargas magnéticas efectivas que pudieran aparecer en otros compuestos artificiales a temperatura ambiente, con el interés práctico que esta novedad podría implicar. Por tanto, la finalidad de la segunda parte de la tesis es encaminar un futuro estudio de posibles nuevos materiales que permitiesen construir dispositivos “magnetrónicos” que posibilitaran la transmisión de energía e información.The work is addressed to analyze two parts that are intimately related. The first one refers to studying the global states and characteristics of their magnetic structures of the compounds called spin-ices and in the second part the behaviors under the electromagnetic interaction in infinite media and in confined systems are analyzed. The main novelty in these compounds is the existence of excited global states at low-temperatures in which structural entities that mimic the behavior of magnetic monopoles arise. In the first part, the low temperature excited states or quasiparticles are studied in compounds of the type (REE)₂Ti₂ O₇, where REE refers to one of the 15 lanthanides, fundamentally Dy₂Ti₂O₇ andHo₂Ti₂O₇. At these temperatures (between 0.05 K and 0.17 K) there is a phase transition with characteristics similar to a Bose Einstein condensate whose individual components are in the form of magnetic dipoles (two monopoles, one with positive magnetic charge and the other negative connected by the "Coulomb interaction" and separated by a distance equivalent to the high of each tetrahedron of the crystalline structure which we described in the text). By increasing the temperature, said dipoles are broken forming a magnetic plasma of free and quasi-free positive and negative magnetic charges whose statistic is of the Fermi-Dirac type. The thermodynamic transition processes are described by analytical models for low energy excitation states and we describe the successive phase transitions. We determine the thermodynamic potentials, specific heat and entropy in which we can show the two possible phase transitions that occur in these compounds. In the second part, we make an analysis of the modified Maxwell equations as well as the generalized Lorentz force in the presence of these magnetic charges. The solution of these equations allows us to obtain data that may have empirical interest in order to detect magnetic monopoles in other natural compounds. We study the transverse electromagnetic propagation in these materials by adding a strong external electric field with which we deduce the density of monopoles per unit volume and the effective mass of the same. We deduce the solutions of these dual Maxwell equations in confined media with rectangular and circular symmetries. In these media in the magnetic plasma phase we obtain the non-linear equation of the system order parameter. The characteristics and properties of the solutions of the modified Maxwell equations are determined in the form of TM modes, obtaining magnetic conductivity as a function of frequency (called magnetricity), magnetic susceptibility, as well as peaks in electromagnetic absorption and other data such as the frequencies of precession and the characteristic frequency of plasma or frequency of plasmon. The achieving of these two frequencies allows us to determine the specific mass assigned to these quasiparticles, being physical magnitude is basic for determining and justifying the conduction properties. The fundamental objective of this part is to perform a systematic analysis to detect in other materials the presence of these possible effective magnetic charges that may appear and have appeared in other artificial compounds even at room temperature, with the practical interest that this novelty may have. The last objective of this second part of the thesis is to make a prospective to study the possibilities of new materials with which to build "magnetronic" devices that allow to transmit energy and information.
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Jarvis, Stuart. "Monopoles on 3-manifolds : the classification of monopoles on R'3." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294344.
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McAllister, Ian. "Monopoles on 3-manifolds." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318849.
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Marques, Fernandes Oliveira Goncalo. "Monopoles in higher dimensions." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/23570.
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The Bogomolnyi equation is a PDE for a connection and a Higgs field on a bundle over a 3 dimensional Riemannian manifold. Possible extensions of this PDE to higher dimensions preserving the ellipticity modulo gauge transformations require some extra structure, which is available both in 6 dimensional Calabi-Yau manifolds and 7 dimensional G2 manifolds. These extensions are known as higher dimensional monopole equations and Donaldson and Segal proposed that 'counting' solutions (monopoles) may give invariants of certain noncompact Calabi-Yau or G2 manifolds. In this thesis this possibility is investigated and examples of monopoles are constructed on certain Calabi-Yau and G2 manifolds. Moreover, this thesis also develops a Fredholm setup and a moduli theory for monopoles on asymptotically conical manifolds.
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Mahassen, Nadim. "Monopoles and complex curves." Thesis, Swansea University, 2002. https://cronfa.swan.ac.uk/Record/cronfa42518.
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In this thesis I study the geometry of the monopole equations on complex curves. The moduli space is shown to be compact and carries a Kahler structure. Zero dimensional moduli spaces are investigated along with their relation to the uniformization theorem. I then study the non-abelian analogue of the equations which can be regarded as a generalization of Yang-Mills theory on Riemann surfaces. Possible relations with three dimensional topology are discussed. Some background material is provided, including an introduction to differential and spin geometry on complex curves and four-manifolds.
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Bisiou, Yann. "Les monopoles des stupéfiants." Paris 10, 1994. http://www.theses.fr/1994PA100118.
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Cette thèse est consacrée à l'étude des monopoles de l'opium et du cannabis dans les colonies françaises entre 1850 et 1954. Les monopoles de l'opium et du cannabis ont été créés dans un but fiscal, en Indochine, au Maroc, en Tunisie, en inde et en Océanie. La première partie de cette thèse en explique les causes, l'organisation administrative et juridique. La seconde partie permet de souligner les limites de ce mode de contrôle des stupéfiants. L'importance des marges bénéficiaires provoque une contrebande importante. Le droit pénal fiscal et la procédure pénale fiscale mis en œuvre pour lutter contre la fraude s'avère, impuissante. L'action internationale en faveur de la prohibition des stupéfiants conduit à la suppression progressive de ces monopoles. La conclusion de la thèse tire les enseignements de l'échec des monopoles fiscaux des stupéfiants dans les colonies françaises. Dans le cadre du débat sur la lutte contre l'abus de stupéfiants, elle propose de créer des monopoles sanitaires et sociaux des stupéfiantsThis thesis concerns the study of opium and marijuana monopolies in French colonies between the years 1850 and 1954. Its presents the administrative and material organization of the monopolies and try to explain the failure of this system. Smuggling development, inefficiency of the penal law and international movement against narcotics drugs abuses make up limits of the tax monopolies of drugs. Conclusion proposes a new type of drug's control based on health and social monopoly of drugs to fight against drug abuse
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Deger, Sinan. "Geometrical Phases And Magnetic Monopoles." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12612989/index.pdf.
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In this thesis, we study the subject of geometrical phases in detail by considering its various forms. We focus primarily on the relation between quantum geometrical phases and magnetic monopoles, and study how one can make use of the concepts of geometrical phases to define magnetic monopoles.
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D'Avanzo, Antonella. "On charge 3 cyclic monopoles." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4728.
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Monopoles are solutions of an SU(2) gauge theory in R3 satisfying a lower bound for energy and certain asymptotic conditions, which translate as topological properties encoded in their charge. Using methods from integrable systems, monopoles can be described in algebraic-geometric terms via their spectral curve, i.e. an algebraic curve, given as a polynomial P in two complex variables, satisfying certain constraints. In this thesis we focus on the Ercolani-Sinha formulation, where the coefficients of P have to satisfy the Ercolani-Sinha constraints, given as relations amongst periods. In this thesis a particular class of such monopoles is studied, namely charge 3 monopoles with a symmetry by C3, the cyclic group of order 3. This class of cyclic 3-monopoles is described by the genus 4 spectral curve X , subject to the Ercolani-Sinha constraints: the aim of the present work is to establish the existence of such monopoles, which translates into solving the Ercolani-Sinha constraints for X . Exploiting the symmetry of the system,we manage to recast the problem entirely in terms of a genus 2 hyperelliptic curve X, the (unbranched) quotient of X by C3 . A crucial step to this aim involves finding a basis forH1( X; Z), with particular symmetry properties according to a theorem of Fay. This gives a simple formfor the period matrix of X ; moreover, results by Fay and Accola are used to reduce the Ercolani-Sinha constraints to hyperelliptic ones on X. We solve these constraints onX numerically, by iteration using the tetrahedral monopole solution as starting point in the moduli space. We use the Arithmetic-GeometricMean method to find the periods onX: this method iswell understood for a genus 2 curve with real branchpoints; in this work we propose an extension to the situation where the branchpoints appear in complex conjugate pairs, which is the case for X. We are hence able to establish the existence of a curve of solutions corresponding to cyclic 3-monopoles.
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Nordström, Axel. "Magnetic Monopoles in Spin Ice." Thesis, KTH, Teoretisk fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145891.
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Faridani, Jacqueline. "Dynamics of nonabelian Dirac monopoles." Thesis, University of Oxford, 1994. http://ora.ox.ac.uk/objects/uuid:71be8f51-cab2-48dc-bb7c-fb0274851c97.
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Ribosomal RNA genes (rDNA) exist in yeast both as a single chromosomal array of tandemly repeated units and as extrachromosomal units named 3um plasmids, although the relationship between these two forms is unclear. Inheritance of rDNA was studied using two systems. The first used a naturally occuring rDNA restriction enzyme polymorphism between two strains to distinguish between their rDNA arrays, and the second involved cloning a tRNA suppressor gene into rDNA to label individual rDNA units. An added interest to the study of the inheritance of rDNA in yeast was the possible association between it and the inheritance of the Psi factor, an enigmatic type of nonsense suppressor in yeast which shows extra-chromosomal inheritance. In a cross heterozygous for the rDNA polymorphism and the psi factor, tetrad analysis suggested that the psi factor had segregated 4:0. The majority of the rDNA units segregated in a 2:2 fashion, which suggested that reciprocal recombination in the rDNA of psi+ diploids is heavily suppressed as was previously shown for psi- diploids. A heterologous plasmid containing the tRNA suppressor gene was constructed and transformed into haploid and diploid hosts. A series of transformants was obtained and physical and genetic analysis suggested that they contained tRNA suppressor gene(s) integrated into their rDNA. In a cross heterozygous for rDNA-tRNA gene insert(s), 6% of the tetrads dissected showed a meiotic segregation of the suppressed phenotype which could most probably be accounted for by inter-chromosomal gene conversion. This observation could be interpreted in two ways. Firstly, recombination intermediates between rDNA on homologues may occur in meiosis, but they are mostly resolved as gene conversions without reciprocal cross-over. Alternatively, gene conversion tracts in rDNA are rare but very long so that the tRNA gene insert was always included in the event. 3um rDNA plasmids containing the tRNA gene marker were not detected in any of the transformants analysed. An extensive quantitative analysis of the rate of reversion of the suppressed phenotype amongst these transformants identified a particulary unstable transformant group. It was proposed that the mechanism of reversion was loss of the tRNA gene insert by unequal sisterstrand exchange, and the mechanism was shown to be independent of the recombination/repair genes RAD1, RAD52, and RAD51. A genetic analysis of stability suggested that there may have been at least two loci segregating in the host strains with additive effects on stability.
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Lin, Francesco Ph D. Massachusetts Institute of Technology. "Monopoles and Pin(2)-symmetry." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104585.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mathematics, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 321-326).
In this thesis we generalize the construction of monopole Floer homology due to Kronheimer and Mrowka to the case of a gradient flow with Morse-Bott singularities. Focusing then on the special case of a three-manifold equipped equipped with a spinc structure which is isomorphic to its conjugate, we define the counterpart in this context of Manolescu's recent Pin(2)-equivariant Seiberg-Witten-Floer homology. In particular, we provide an alternative approach to his disproof of the celebrated Triangulation conjecture. Furthermore, we discuss the analogue in this setting of the surgery exact triangle, and perform some sample computations.
by Francesco Lin.
Ph. D.
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Howes, Stephen John. "Lumps, rational maps and monopoles." Thesis, Swansea University, 2001. https://cronfa.swan.ac.uk/Record/cronfa43020.
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Kronenberger, Vincent. "Le monopole des alcools en Finlande : exemple de la mutation des monopoles publics en droit communautaire." Toulouse 1, 1999. http://www.theses.fr/1999TOU10001.
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Le monopole public des alcools en Finlande a connu une transformation sans précédents depuis l'adhésion de la Finlande à la communauté européenne en 1995. Poursuivant un objectif de protection de la santé publique, l'entreprise monopolistique fut dotée d'un large éventail d'exclusivités et de privilèges. Ne subsiste aujourd'hui que le monopole de commercialisation au détail, structurellement séparé des autres activités de l'ancien monopole intégré. Cette étude sur le monopole finlandais, particulièrement intéressant, dresse une typologie puis érige un modèle de la mutation des monopoles publics en droit communautaire, applicable à tous les secteurs monopolistiques actuellement en cours de libéralisation (postes, ferroviaire, électricité. . . ). Retenant une acception fonctionnelle et institutionnelle du monopole public, cette recherche isole quatre modalités de mutation regroupées en deux catégories. D'une part, une mutation fonctionnelle par un processus de libéralisation puis la séparation des activités économiques et de police spéciale du monopole. Le monopole est circonscrit, mais pas nécessairement condamné : la jurisprudence récente l'atteste. D'autre part, une mutation institutionnelle par la désintégration puis la distanciation du monopole de l'État. L'isolement devient alors plus prononcé. Au final, par delà les bases juridiques du traité CE, l'exemple du monopole finlandais des alcools rend compte d'une véritable politique juridique des institutions communautaires. L'interprétation audacieusement libérale du traité laisse aujourd'hui la place à une approche qui tolère davantage le monopole, tout en l'isolant. Cette phase ne saurait cependant constituer l'aboutissement de l'évolution du droit communautaireThe Finnish alcohol monopoly has gone through an unprecedented transformation following Finland’s accession to the European community in 1995. Pursuing a public health mission, the state monopoly had obtained extensive exclusive rights and privileges. Today, there remains only the retail sale monopoly which is entirely independent from other parts of the formerly integrated monopoly. This research on the particularly interesting example of the Finnish monopoly, draws up a typology and sets a model for transformation of state monopolies in EC law, which is applicable to all monopolistic sectors currently under liberalisation (postal services, railways, electricity. . . ). This study retains both a functional and institutional definition of state monopolies and therefore of their transformation. First, a functional transformation consisting in both liberalisation and separation of economical and regulatory functions of the monopoly. The shape of the monopoly is reduced but its existence is not necessarily condemned, as recent case-law indicates. Second, an institutional transformation: unbundling and + distanciation; from the state. The monopoly is even more isolated. In the end, besides the EC treaty's legal basis, the Finnish monopoly example reveals a genuine judicial policy of community institutions towards monopolies. The former daringly liberal interpretation of the treaty has been replaced today by a more neutral approach which tolerates monopolies, provided their + confinement. However this phase is expected not to be the final step of EC law
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Yang, Fangyun Ph D. Massachusetts Institute of Technology. "Dirac operators and monopoles with singularities." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41723.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2007.Includes bibliographical references (p. 75-77).
This thesis consists of two parts. In the first part of the thesis, we prove an index theorem for Dirac operators of conic singularities with codimension 2. One immediate corollary is the generalized Rohklin congruence formula. The eta function for a twisted spin Dirac operator on a circle bundle over a even dimensional spin manifold is also derived along the way. In the second part, we study the moduli space of monopoles with singularities along an embedded surface. We prove that when the base manifold is Kahler, there is a holomorphic description of the singular monopoles. The compactness for this case is also proved.
by Fangyun Yang.
Ph.D.
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Cockburn, Alexander Hugh. "Aspects of vortices and hyperbolic monopoles." Thesis, Durham University, 2015. http://etheses.dur.ac.uk/11107/.
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This thesis discusses BPS monopoles in hyperbolic space and BPS vortices in the presence of magnetic impurities. We prove explicit formulae for the spectral curve and rational map of a JNR-type hyperbolic monopole, and we use these to study some Platonic examples as well as some new 1-parameter families analogous to Euclidean monopole scattering. Explicit fields and Braam-Austin data for axial hyperbolic monopoles of a particular mass are derived using a correspondence to 1-monopoles, and this data is deformed to give new 1-parameter families. Numerical techniques are used to study the effect of magnetic impurities on vortices on a flat background. Analytic results for vortices with magnetic impurities are found by adapting previous results on vortices on the hyperbolic plane and the 2-sphere.
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Braam, Peter J. "Magnetic monopoles and hyperbolic three-manifolds." Thesis, University of Oxford, 1987. http://ora.ox.ac.uk/objects/uuid:daa73d43-6d58-404c-9926-ebf23f59cfc6.
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Let M = H3/Γ be a complete, non-compact, oriented geometrically finite hyperbolic 3-manifold without cusps. By constructing a conformal compactification of M x S1 we functorially associate to M an oriented, conformally flat, compact 4-manifold X (without boundary) with an S1-action. X determines M as a hyperbolic manifold. Using our functor and the differential geometry of conformally flat 4-manifolds we prove that any Γ as above with a limit set of Hausdorff dimension ≤ 1 is Schottky, Fuchsian or extended Fuchsian. Furthermore, the Hodge theory for H2 (X;R) carries over to H1(M, δM;R) and H2(M;R) which correspond to the spaces of harmonic L2-forms of degree 1 and 2 on M. Comparison of lattices through the Hodge star gives an invariant h(M) ε GL(H2(M;R)/GL(H2(M;Z)) of the hyperbolic structure. Secondly we pay attention to magnetic monopoles on M which correspond to S1invariant solutions of the anti-self-duality equations on X. The basic result is that we associate to M an infinite collection of moduli spaces of monopoles , labelled by boundary conditions. We prove that the moduli spaces are not empty (under reasonable conditions), compute their dimension , prove orientability , the existence of a compactification and smoothness for generic S1-invariant conformal structures on X. For these results one doesn't need a hyperbolic structure on M , the existence of a conformal compactification X suffices. A twistor description for monopoles on a hyperbolic M can be given through the twistor space of X , and monopoles turn out to correspond to invariant holomorphic bundles on twistor space. We analyse these bundles. Explicit formulas for monopoles can be found on handlebodies M , and for M = surface x R we describe the moduli spaces in some detail.
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Rychenkova, Paulina. "Geometry of monopoles and domain walls." Thesis, University of Cambridge, 1999. https://www.repository.cam.ac.uk/handle/1810/270438.
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Gharamti, Moustafa. "Supersymmetry and geometry of hyperbolic monopoles." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/10479.
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This thesis studies the geometry of hyperbolic monopoles using supersymmetry in four and six dimensions. On the one hand, we show that starting with a four dimensional supersymmetric Yang-Mills theory provides the necessary information to study the geometry of the complex moduli space of hyperbolic monopoles. On the other hand, we require to start with a six dimensional supersymmetric Yang-Mills theory to study the geometry of the real moduli space of hyperbolic monopoles. In chapter two, we construct an off-shell supersymmetric Yang-Mills-Higgs theory with complex fields on three-dimensional hyperbolic space starting from an on-shell supersymmetric Yang-Mills theory on four-dimensional Euclidean space. We, then, show that hyperbolic monopoles coincide precisely with the configurations that preserve one half of the supersymmetry. In chapter three, we explore the geometry of the moduli space of hyperbolic monopoles using the low energy linearization of the field equations. We find that the complexified tangent bundle to the hyperbolic moduli space has a 2-sphere worth of integrable structures that act complex linearly and behave like unit imaginary quaternions. Moreover, we show that these complex structures are parallel with respect to the Obata connection, which implies that the geometry of the complexified moduli space of hyperbolic monopoles is hypercomplex. We also show, as a requirement of analysing the geometry, that there is a one-to-one correspondence between the number of solutions of the linearized Bogomol’nyi equation on hyperbolic space and the number of solutions of the Dirac equation in the presence of hyperbolic monopole. In chapter four and five, we shift the focus to supersymmetric Yang-Mills theories in six dimensional Minkowskian spacetime. Via dimensional reduction we construct a supersymmetric Yang-Mills Higgs theory on R3 with real fields which we then promote to H3. Under certain supersymmetric constraints, we show that hyperbolic monopoles configurations of this theory preserve, again, one half of the supersymmetry. Then, through investigating the geometry of the moduli space we showthat the moduli space is described by real coordinate functions (zero modes), and we construct two sets of 2-sphere of real complex structures that act linearly on the tangent bundle of the moduli space, but don’t behave like unit quaternions. This result coincides with the result of Bielawski and Schwachhöfer, who called this new type of geometry pluricomplex geometry. Finally, we show that in the limiting case, when the radius of curvature H3 is set to infinity, the geometry becomes hyperkähler which is the geometry of the moduli space of Euclidian monopoles.
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Wang, Bai-Ling. "Seiberg-Witten monopoles on three-manifolds /." Title page, abstract and contents only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phw2455.pdf.
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Somogyi, Robert. "Essays on capacity-constrained pricing." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX024/document.
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Cette thèse est composée de trois chapitres. Le premier chapitre, "Bertrand-Edgeworth Competition with Substantial Product Differentiation", étudie le comportement d'un duopole lorsque les deux entreprises sont caractérisées par des contraintes de capacité et produisent un bien différencié à la Hotelling. En limitant l'analyse au cas d'un degré élevé de différentiation du produit, je démontre l'existence d'au moins un équilibre en stratégie pure pour tous les niveaux de capacités. Le deuxième chapitre, "Monopoly Pricing with Dual Capacity Constraints" analyse un monopole qui est contraint par deux types de contraintes de capacité: un sur la quantité produite, l'autre sur le nombre des consommateurs. Je démontre que les prix optimaux choisis par les entreprises en court terme ne sont pas monotones dans le niveau des contraintes de capacité. En outre, le bien-être agrégé des consommateurs peut décroître si une des contraintes de capacité est augmentée. Le troisième chapitre, "Competition with Dual Capacity Constraints", étend l'analyse du deuxième chapitre au cas du duopole symétrique dans lequel les deux entreprises font face aux mêmes niveaux de capacité. Je démontre l'existence de conditions sous lesquelles la non-monotonicité des prix et du bien-être des consommateurs observée dans le 2ème chapitre est également présente dans le cas du duopole. Certains équilibres donnent naissance à des prix de duopole égaux au prix de monopole. En outre, les entreprises peuvent choisir des prix d'équilibre identiques sur les deux marchés malgré leur pouvoir de discrimination des prixThis Ph.D. thesis is composed of three chapters. Since Kreps and Scheinkman's seminal article (1983) a large number of papers have analyzed capacity constraints' potential to relax price competition. However, the majority of the ensuing literature has assumed that products are either perfect or very close substitutes. Therefore very little is known about the interaction between capacity constraints and local monopoly power. The aim of the present paper is to shed light on this question using a standard Hotelling setup. The high level of product dierentiation results in a variety of equilibrium firm behavior and it generates at least one pure-strategy equilibrium for any capacity level. The second chapter, "Bertrand-Edgeworth Competition with Substantial Product Differentiation", studies the price-setting behavior of a monopoly facing two capacity constraints: one on the number of consumers it can serve, the other on the total amount of products it can sell. Facing two consumer groups that difer in their demands and the distribution of their willingness-to-pay, the monopoly's optimal non-linear pricing strategy consists of offering one or two price-quantity bundles. The characterization of the firm's optimal pricing as a function of its two capacities reveals a rich structure that also gives rise to some surprising results. In particular, I show that prices are non-monotonic in capacity levels. Moreover, there always exists a range of parameters in which weakening one of the capacity constraints decreases consumer surplus. In the long run, when the firms can choose how much capacity to build, prices and consumer surplus are monotonic in capacity costs. The third chapter, "Competition with Dual Capacity Constraints", studies duopoly pricing under dual capacity constraints, limiting both the total quantity and the number of consumers served. It extends both the analysis of monopoly pricing with dual capacity constraints and the symmetric models of Bertrand-Edgeworth competition with a singular capacity. By isolating parameter regions where a symmetric pure-strategy equilibrium exists, I nd that several types of equilibria are possible, depending on the model's specications. For some of them, duopoly prices are identical to monopoly prices. Equilibrium prices are non-monotonic in capacity levels if consumers' valuations are suciently heterogeneous. Moreover, I show that despite their ability to price discriminate, competition may lead firms to charge identical prices across markets
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Tong, D. M. "Instantors, monopoles, and three dimensional gauge theories." Thesis, Swansea University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.639250.
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In this thesis we develop semi-classical techniques in three-dimensional gauge theories and apply them to models with extended supersymmetry. We investigate extensively the correspondence between three-dimensional gauge thesis with N = 4 supersymmetry and monopole moduli spaces. In the case of SU(z) gauge theory, we prove that the Coulomb branch is equivalent to the centred moduli space of two BPS monopoles constructed by Atyah and Hitchin. For SU(z) gauge groups, the results give new information about the moduli space of n BPS monopoles. We further extend the correspondence to include monopole moduli spaces of all simply-laced Lie groups. We also consider instanton effect in N=2 and N=8 theories.
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Barrett, Jessica K. "Aspects of D-branes as BPS monopoles." Thesis, Durham University, 2004. http://etheses.dur.ac.uk/3160/.
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We investigate some of the properties of D-brane configurations which behave as BPS monopoles. The two D-brane configurations we will study are the enhançon and D-strings attached to D3-branes.We will start by investigating D3-branes wrapped on a K3 manifold, which are known as enhançons. They look like regions of enhanced gauge symmetry in the directions transverse to the branes, and therefore behave as BPS monopoles. We calculate the metric on moduli space for n enhançons, following the methods used by Ferrell and Eardley for black holes. We expect the result to be the higher-dimensional generalisation of the Taub-NUT metric, which is the metric on moduli space for n BPS monopoles. Next we will study D-strings attached to D3-branes; the ends of the D-strings behave as BPS monopoles of the world volume gauge theory living on the D3-branes. In fact the D-string/D3-brane system is a physical realisation of the ADHMN construction for BPS monopoles. We aim to test this correspondence by calculating the energy radiated during D-string scattering, working with the non-Abelian Born-Infeld action for D-strings. We will then compare our result to the equivalent monopole calculation of Manton and Samols.
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Mulhearn, Michael James. "A direct search for Dirac magnetic monopoles." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32420.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, June 2005.Includes bibliographical references (p. 159-164).
Magnetic monopoles are highly ionizing and curve in the direction of the magnetic field. A new dedicated magnetic monopole trigger at CDF, which requires large light pulses in the scintillators of the time-of-flight system, remains highly efficient to monopoles while consuming a tiny fraction of the available trigger bandwidth. A specialized offline reconstruction checks the central drift chamber for large dE/dx tracks which do not curve in the plane perpendicular to the magnetic field. We observed zero monopole candidate events in 35.7 pb⁻¹ of proton-antiproton collisions at ... = 1.96 TeV. This implies a monopole production cross section limit [sigma] < 0.2 pb for monopoles with mass between 100 and 700 GeV, and, for a Drell-Yan like pair production mechanism, a mass limit m > 360 GeV.
by Michael James Mulhearn.
Ph.D.
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Mountain, Arthur James. "Studies of supersymmetry, symmetry groups and monopoles." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624126.
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Retterer, Stéphane. "Monopoles publics et démonopolisation en droit communautaire." Toulon, 1995. http://www.theses.fr/1995TOUL0020.
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Lalanne, Bertin. "Analyse économique de l'efficacité des sanctions antitrust." Montpellier 1, 2000. http://www.theses.fr/2000MON10060.
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L'action des autorites antitrust vise a etablir les conditions propices au developpement d'une concur♭ rence saine, en sanctionnant et dissuadant les pratiques illicites. Elle se heurte notamment a deux obstacles: l'asymetrie informationnelle et la limite reglementaire des sanctions. Nous etudions l'effi♭ cacite de la politique antitrust quand la sanction ne suffit pas a dissuader la collusion. Dans le pre♭ mier chapitre, nous mettons en perspective les contributions de differents auteurs a la definition d'une politique antitrust optimale. Nous soulignons la difficulte de la prise en compte de la recidive et la revelation d'information induite par l'enquete des autorites avec ses eventuelles consequences sur la strategie de prix limite. Dans le deuxieme chapitre, nous montrons qu'avec unesanction limi♭ tee, les autorites ont interet a la fixer au maximum des la premiere condamnation. Nous considerons dans le troisieme chapitre que la sanction est reglementairement limitee et que toute enquete des autorites revele l'information sur la profitabilite des entreprises et induit l'entree. Dans ce cadre, une politique antitrust declic est optimale, laissant un leger profit collusoire aux entreprises. Nous tes♭ tons dans le quatrieme chapitre l'impact d'une telle politique antitrust sur un cartel qui desire mettre en place une strategie de prix limite. L'action des autorites contribue a rendre le marche plus trans♭ parent et assure un niveau de production minimum. Le cinquieme chapitre est consacre a l'etude de l'efficacite de la politique antitrust europeenne et plus precisementa l'action de la commission. Les evolutions actuelles de la politique antitrust vont dans le sens d'une efficacite accrue mais la com♭ mission gagnerait a etre plus severe. L'efficacite etant egalement liee a une meilleure comprehen♭ sion de l'organisation et du fonctionnement des ententes, nous proposons une typologie de la struc♭ ture et des agissements des cartels.
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Bonsdorff, Juhani. "A Fourier transform for Higgs bundles." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249510.
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Gbaguidi, David Sedo. "Réseaux, réglementation et risques." Sherbrooke : Université de Sherbrooke, 2003.
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Rens, Bram Antonius Philomena van. "Detection of magnetic monopoles below the Cherenkov limit." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2006. http://dare.uva.nl/document/23682.
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Hart, A. "Magnetic monopoles and confinement in lattice gauge theory." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337718.
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Khandhawit, Tirasan. "Twisted Manolescu-Floer spectra for Seiberg-Witten monopoles." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82439.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 123-125).
In this thesis, we extend Manolescus and Kronheimer-Manolescus construction of Floer homotopy type to general 3-manifolds. This Floer homotopy type is a candidate for an object whose suitable homology groups recover Floer homology. The main idea is to apply finite dimensional approximation technique and Conley index theory to Seiberg-Witten theory of 3-manifolds. Another part of the construction involves a concept of twisted parametrized spectra introduced by Douglas. We also provide explicit computation for the manifolds S 1 x S 2 and T 3 .
by Tirasan Khandhawit.
Ph.D.
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Dyer, Ethan Stanley. "Strings and monopoles in strongly interacting gauge theories." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91077.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2014.127
Title as it appears in MIT commencement exercises program, June 6, 2014: Few uses of low-dimensional gauge theory Cataloged from PDF version of thesis.
Includes bibliographical references (pages 201-209).
In this thesis we discuss aspects of strongly coupled gauge theories in two and three dimensions. In three dimensions, we present results for the scaling dimension and transformation properties of monopole operators in gauge theories with large numbers of fermions. In two dimensions, we study (0,2) gauge theories as a tool for constructing string backgrounds with non trivial H-flux. We demonstrate how chiral matter content in the gauge theory allows the construction of infrared fixed points outside of the usual Calabi-Yau framework, and further derive consistency relations for a special class of torsional models.
by Ethan Stanley Dyer.
Ph. D.
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Striebel, Martin. "Magnetic monopoles in a constant background gauge field /." [S.l : s.n.], 1987. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Striebel, Michael. "Magnetic monopoles in a constant background gauge field." Bern, 1987. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Nießen, Peter. "Search for relativistic magnetic monopoles with the AMANDA detector." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2001. http://dx.doi.org/10.18452/14579.
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Diese Arbeit beschreibt die Suche nach relativistischen magnetischen Monopolen mit dem AMANDA Detektor. Die Methoden der Simulation und der Untergrundseparation werden erläutert. Keine Spuren mit der Signatur eines magnetischen Monopols wurden gefunden. Das sich ergebende Flusslimit von 0.61x10^-16 1/(cm^2 sr s) für Monopole, die sich nahe der Lichtgeschwindigkeit bewegen, liegt um einen Faktor 3-4 besser als die Ergebnisse vergleichbarer Untergrundexperimente und einen Faktor 16 unterhalb der Grenze, die aus der beobachteten Stabilität der galaktischen Magnetfelder liegt.This thesis describes the search for relativistic magnetic monopoles with the AMANDA detector. The methods of their simulation and their separation from the background are given. No tracks with the signature of a magnetic monopoles are found, resulting in an upper limit on the flux of 0.61x10^-16 1/(cm^2 sr s) for monopoles with velocities close to the speed of light. This is better by a factor of 3-4 compared to results from other underground detectors and a factor of 16 below the limit derived from the observed stability of the galactic magnetic fields.
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Niessen, Peter. "Search for relativistic magnetic monopoles with the AMANDA detector." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=961695013.
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Pande, Ashwin S. "Topological T-duality KK-monopoles, g erbes and automorphisms /." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/6835.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Mathematics. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Fraser, C. "Supersymmetric monopoles and duality in non-abelian gauge theories." Thesis, Swansea University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637008.
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The principal subject of this thesis is the study of various aspects of supersymmetric magnetic monopoles in four dimensional gauge theories, with particular emphasis on gauge theories with gauge groups larger than SU(2). The classical theory of bosonic magnetic monopoles is reviewed in some detail, as well as the basics of four dimensional supersymmetry, with emphasis on the role of central charges. The generalisations of electric-magnetic duality to Yang-Mills theory with N = 2 and N = 4 supersymmetries and with higher rank gauge group are presented. The approach relies on analyses of the massive BPS spectrum of dyonic states. Finally, applications of these results upon dimensional reduction to three dimensions are presented, in particular in the determination of new exponential corrections to the SU(2) multi-monopole moduli space metric.
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Curley, D. P. "Non-abelian monopoles and their interactions with charged particles." Thesis, University of Kent, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356566.
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Koratzinos, Michael. "Charmed particle photoproduction and a search for magnetic monopoles." Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/46873.
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Kottke, Christopher N. (Christopher Nicholas). "Index theorems and magnetic monopoles on asymptotically conic manifolds." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/60193.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 101-102).
In this thesis, I investigate the index of Callias type operators on asymptotically conic manifolds (also known as asymptotically locally Euclidean manifolds or scattering manifolds) and give an application to the moduli space of magnetic monopoles on these spaces. The index theorem originally due to C. Callias and later generalized by N. Anghel and others concerns operators of the form ... is a family of Hermitian invertible matrices. The first result is a pseudodifferential version of this index theorem, in the spirit of of the K-theoretic proof of the Atiyah-Singer index theorem, using the theory of scattering pseudodifferential operators. The second result is an extension to the case where [Iota] has constant rank nullspace bundle at infinity, using a b-to-scattering transition calculus of pseudodifferential operators. Finally I discuss magnetic monopoles, which are solutions to the Bogomolny equation ... principal bundle over a complete 3-manifold, and I show how the previous results can be applied to compute the dimension of the moduli space of monopoles over asymptotically conic manifolds whose boundary is homeomorphic to a disjoint union of spheres.
by Christopher N. Kottke.
Ph.D.
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Foscolo, Lorenzo. "On moduli spaces of periodic monopoles and gravitational instantons." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/14270.
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The topic of this thesis is the study of moduli spaces of periodic monopoles (with singularities), i.e. (singular) solutions to the Bogomolny equation (the dimensional reduction of the anti-self-duality equation to 3 dimensions) on R2 x S1. Using arguments from physics, Cherkis and Kapustin gave strong evidence that 4–dimensional moduli spaces of (singular) periodic monopoles yield examples of gravitational instantons (i.e. complete hyperkähler 4–manifolds with decaying curvature) of type ALG. Recently, Hein constructed ALG metrics by solving a complex Monge- Ampère equation on the complement of a fibre in a rational elliptic surface. The thesis is the first step in a programme aimed to verify Cherkis and Kapustin’s predictions and understand them in relation to Hein’s construction. More precisely: (i) We construct moduli spaces of periodic monopoles (with singularities) and show that they are smooth hyperkähler manifolds for generic choices of parameters. (ii) For each admissible choice of charge and number of singularities (and under additional conditions on the parameters in certain cases), we show that moduli spaces of periodic monopoles (with singularities) are non-empty by gluing methods. After presenting these results, we will conclude the thesis with an outline of the other steps in the programme.
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Dar, Shahida. "TeV scale leptogenesis, primordial monopoles, and supersymmetry at LHC." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 129 p, 2008. http://proquest.umi.com/pqdweb?did=1601522291&sid=3&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Alvarez, José Luis Alejo. "Electric-magnetic duality in N = 2 supersymmetric gauge theory /." São Paulo, 2015. http://hdl.handle.net/11449/154699.
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Orientador: Nathan Jacob BerkovitsBanca: Horatiu Stefan Nastase
Banca: Diego Trancanelli
Resumo: Nesta dissertação apresentamos uma descrição da dualidade elétrica-magnética e seus aspectos clássicos e quânticos. Nosso análise se inicia com os monopolos magéticos sugeridos por Dirac em 1931[1] e vai até o trabalho do Seiberg e Witten em 1994 [27]. Na descrição clássica, precisamos introduzir os monopolos magnéticos a fim de obter a dualidade elétrica-magnética manifesta. Mais tarde, a origem dos monopolos se mais torna mais clara quando começamos com uma teoria de Yang-Mills. Os aspectos clássicos da teoria foram explicados pela conjetura de Montonen e Olive 1977 [7]. Explorando os aspectos quânticos da teoria, notamos a importância de introduzir supersimetria, principalmente supersimetria estendida, onde tiramos vantagem da propiedade de holomorficidade, a qual nos leva aos teoremas não renormalizáveis, onde o cálculo é mais simples. Focamos na teoria de gauge supersimétrica N = 2 SU(2). A teoria é completamente resolvível para baixas energias. A maior parte do conteúdo deste trabalho é baseada nas várias revisões da dualidade de Seiberg-Witten [30],[31],[32]
Abstract: In this dissertation we present a description of the electric-magnetic duality and their classical and quantum aspects. Our analysis starts from the suggested magnetic monopoles by Dirac in 1931 [1] and goes until the work of Seiberg and Witten in 1994 [27]. In the classical description, we need to introduce the magnetic monopoles in order to make manifest the electricmagnetic duality. Later, the origin of monopoles becomes clear when we start from a Yang-Mills theory. The classical aspects of the E-M duality are covered in the Montonen-Olive conjecture 1977[7]. Working on the quantum aspects of the theory, we note the importance of introducing supersymmetry. Specially for extended supersymmetry, where we take advantage of the holomorphicity property, which leads us to the non-renormalizable theorems, where the computation is easier. We focus on theN = 2SU(2) supersymmetric gauge theories. It turns out that the theory is fully solvable at the low energies regime[27]. Most of this work is based on reviews about the Seiberg and Witten duality [30],[31],[32]
Mestre
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Alvarez, José Luis Alejo [UNESP]. "Electric-magnetic duality in N = 2 supersymmetric gauge theory." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/154699.
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Nesta dissertação apresentamos uma descrição da dualidade elétrica-magnética e seus aspectos clássicos e quânticos. Nosso análise se inicia com os monopolos magéticos sugeridos por Dirac em 1931[1] e vai até o trabalho do Seiberg e Witten em 1994 [27]. Na descrição clássica, precisamos introduzir os monopolos magnéticos a fim de obter a dualidade elétrica-magnética manifesta. Mais tarde, a origem dos monopolos se mais torna mais clara quando começamos com uma teoria de Yang-Mills. Os aspectos clássicos da teoria foram explicados pela conjetura de Montonen e Olive 1977 [7]. Explorando os aspectos quânticos da teoria, notamos a importância de introduzir supersimetria, principalmente supersimetria estendida, onde tiramos vantagem da propiedade de holomorficidade, a qual nos leva aos teoremas não renormalizáveis, onde o cálculo é mais simples. Focamos na teoria de gauge supersimétrica N = 2 SU(2). A teoria é completamente resolvível para baixas energias. A maior parte do conteúdo deste trabalho é baseada nas várias revisões da dualidade de Seiberg-Witten [30],[31],[32]
In this dissertation we present a description of the electric-magnetic duality and their classical and quantum aspects. Our analysis starts from the suggested magnetic monopoles by Dirac in 1931 [1] and goes until the work of Seiberg and Witten in 1994 [27]. In the classical description, we need to introduce the magnetic monopoles in order to make manifest the electricmagnetic duality. Later, the origin of monopoles becomes clear when we start from a Yang-Mills theory. The classical aspects of the E-M duality are covered in the Montonen-Olive conjecture 1977[7]. Working on the quantum aspects of the theory, we note the importance of introducing supersymmetry. Specially for extended supersymmetry, where we take advantage of the holomorphicity property, which leads us to the non-renormalizable theorems, where the computation is easier. We focus on theN = 2SU(2) supersymmetric gauge theories. It turns out that the theory is fully solvable at the low energies regime[27]. Most of this work is based on reviews about the Seiberg and Witten duality [30],[31],[32]
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Schlub, Robert Walter, and n/a. "Practical Realization of Switched and Adaptive Parasitic Monopole Radiating Structures." Griffith University. School of Microelectronic Engineering, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040610.112148.
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Switched and adaptive parasitic monopole array radiating structures are investigated. Antenna design is orientated toward increasing practicability for implementation in terrestrial wireless communication systems. A number of antennas are designed with the aid of optimization and commercial simulation software. Simulation procedure was verified with the experimental manufacture and measurement of the arrays. The antennas presented in this thesis comprise an active monopole surrounded by a ring of parasitic monopoles. Parasitic radiators are constructed with static loading to enable simple experimental realization. Beam positions of an electrically steered equivalent antenna are thus simulated. Antenna symmetry ensures the beam can be reproduced throughout the azimuth. Complex antenna geometries require antenna design through optimization. A genetic algorithm is employed with HFSS and NEC for electromagnetic analysis. The robust optimization method couples with simulation software flexibility to provide an effective design tool for arbitrary structures. The genetic algorithm is employed strictly for design and not complete structural optimization. Dual band, five and six element switched parasitic antennas are presented. Lumped elemental loading along the radiators provide resonance and directed radiation at two GSM frequencies. Load value, radiator dimension and spacing are incorporated as design parameters. Experimentally built, 10dB return loss bandwidths of 17.2% and 9.6% and front to back ratios of 12.6dB and 8.4dB at 900MHz and 1900MHz respectively are measured. To reduce the ground requirements of monopole arrays, a skirted ground structure for switched parasitic antennas is analyzed. A six element switched parasitic monopole array with conductive ground skirt exhibits a front to back ratio of 10.7dB and main lobe gain of 6.4dBi at 1.575GHz. Radiation is not elevated despite lateral ground terminating at the parasitic elements. Skirt height is observed to linearly control radiation elevation, depressing the principal lobe through 40 degrees from 23 degrees above the horizontal. The Electronically Steerable Passive Array Radiator or ESPAR antenna is an adaptive parasitic monopole array. An ESPAR radiating structure incorporating a conductive ground skirt is designed for operation at 2.4GHz. Utility is confirmed with a frequency sensitivity analysis showing consistent electrical characteristics over an 8.1% bandwidth. The antenna design is improved with optimization to reduce average principal lobe elevation from 25 degrees to 9.7 degrees.