Дисертації: "String and Branes Theory"

1

Stefański, Bogdan. "String theory, dirichlet branes and K-theory." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621023.

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2

Sigalov, Ilya. "D-branes and string field theory." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/39560.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2006.
Includes bibliographical references (p. 115-127).
In this thesis we study the D-brane physics in the context of Witten's cubic string field theory. We compute first few terms the low energy effective action for the non-abelian gauge field A, from Witten's action. We show that after the appropriate field redefinition which relates the string field theory variables to the worldsheet variables one obtains the correct Born-Infeld terms. We then compute the rolling tachyon solution in the context of string field theory. We show that after the appropriate field redefinition we obtain the rolling tachyon solution of Sen.
by Ilya Sigalov.
Ph.D.

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3

Ng, Selena Kim Leng. "Aspects of branes in string theory." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620652.

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4

Feng, Bo 1971. "D-branes, gauge theory and string field theory." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8491.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 2002.
Includes bibliographical references (p. 245-262).
In this thesis, we present several works done in last three years. They include three directions in the string theory. In the first direction, we use the brane setup to find mirror pairs of SO(n) and Sp(k) gauge groups for N = 4 three-dimensional gauge field theories. To reach this result, we analyze carefully the s-configuration and predict a nontrivial string dynamics, i.e., the splitting of branes on the orientifold planes. In the second direction, we develop the "inverse algorithm" and use it to get nontrivial world volume theories of D-branes probing more exotic singularities. In this process, we find the "toric duality" which relates different phases of D-brane probe theories. We realize later that the toric duality is an example of the more powerful Seiberg-duality so these different phases are related by the Seiberg duality. In the third direction, by using numerical calculation we get a strong evidence to support the second conjecture of Sen's three conjectures. We show that if the identity field is BRST exact state around the tachyon vacuum, the open string spectrum will decouple from the physics and leave only the closed string spectrum.
by Bo Feng.
Ph.D.

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5

Karch, Andreas. "Field Theory Dynamics from branes in String Theory." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 1998. http://dx.doi.org/10.18452/14371.

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Nach jahrelanger Suche hat sich bis heute Stringtheorie als einziger Kandidat einer konsistenten Quantentheorie der Gravitation herauskristallisiert. Um aus der Stringtheorie präzise Vorhersagen für unsere Niederenergiewelt zu gewinnen, ist es notwendig, das Vakuumproblem zu lösen, das heißt einen Mechanismus zu finden, der aufzeigt, in welchem Stringvakuum wir leben und warum die Natur dieses ausgewählt hat. Die Beantwortung dieser Frage benötigt nicht-perturbative Informationen.Diese wurden erst in jüngster Zeit zugänglich. Eine besondere Rolle in dieser Entwicklung spielten die sogenannten D-branes. Sie stellen mögliche nicht-perturbative Beiträge zu Stringamplituden dar. Die Identifizierung, daß D-branes einfach Objekte sind, auf denen Strings enden können, ermöglicht sie zu handhaben und zu zeigen, daß ihre Dynamik im wesentlichen durch Eichtheorien erfaßt wird. D-branes erlaubten, zahlreiche Dualit\ätssymmetrien zu etablieren, deren Haupta ussage zu sein scheint, daß alle 5 Stringtheorien sowie 11d Supergravitation nur verschiedene perturbative Limites einer fundamentalen 11d Theorie sind, T-Theorie. In dieser Arbeit habe ich mich mit einigen Anwendungen dieser Ideen beschäftigt. Die Tatsache, daß D-branes durch Super Yang-Mills Theorien beschrieben werden, erlaubt uns einen Stringhintergrund derart zu präparieren, daß wir nahezu jede Eichtheorie als relevante Niederenergiebeschreibung erhalten können. Eine besonders verbreitete Variante dieser Idee sind die sogenannten ``Hanany Witten setups'', in denen dieser Stringhintergrund nur aus flachen branes im flachen Raum besteht. Mit Hilfe dieser Technik habe ich verschiedene Dualitätssymmetrien in Feldtheorien auf Stringdualitäten zurückgeführt. Ferner ist es möglich, mit Hilfe der branes die Existenz nicht trivialer Fixpunkt Theorien in sechs Dimensionen zu beweisen und einige ihrer Eigenschaften zu analysieren. Einige dieser Fixpunkte beschreiben Phasenübergänge zwischen verschiedenen brane Hintergründen. Unter anderem läßt es sich auf diese Weise zeigen, daß es in 4 Dimensionen Übergänge zwischen chiralen und nicht chiralen Vacua gibt. Ferner wurde gezeigt, daß alle anderen Zugänge zu dem Problem, Eichtheorien in Stringtheorie einzubetten, im wesentlichen äquivalent zum HW Ansatz sind, in dem Sinn, daß die entsprechenden Stringhintergründe dual zueinander sind. Dadurch können neue Aspekte der String T-Dualität verstanden werden, so wie z.B. T-Dualitäat für brane Segmente und gebogene branes.Außerdem erlaubt uns diese Verbindung, die Phasenübergänge, die wir im HW Bild entdeckt haben, tatsächlich als Übergänge zwischen topologisch verschiedenen Stringkompaktifizierungen zu verst ehen.
In this thesis I discussed several applications of the connection of non-perturbative string theory and SYM theory. In Chapter 1 I reviewed the physics of D-branes as one example of a non-perturbative effect in string theory. Their dynamics is dominated by gauge theory. This fact can be used to engineer certain string backgrounds which yield interacting SYM theories as their low-energy description. In Chapter 2 I then introduced one of the approaches in detail, the HW setup. I gave a summary of the identification of the classical gauge theory, showed how quantum effects manifest themselves in the brane picture and how to solve them. This way of embedding gauge theories into string theories has several interesting applications. These were the topic of Chapter 3. First I discussed dualities in field theory and showed how they arise as a natural consequence of string duality. As a second application I used branes to prove the existence of non-trivial fixed point theories in 6 dimensions and to study their properties. Some of these fixed points describe phase transitions between two different brane configurations. From a 4d point of view these 6d transitions can induce a chiral non-chiral transition. In Chapter 4 I discussed the relation of the HW setup with the other approaches of embedding gauge theory into string theory, especially the branes as probes approach. The different ways of embedding gauge theories in string theory are shown to be actually T-dual as string backgrounds. For one this allowed us to explore several new aspects of T-duality, like T-duality for bended branes and branes endin g on branes. In addition this relation can be used to show that the transitions found in the brane picture can as well be understood as transitions between topologically distinct compactifications of string theory. Some open problems and directions for further research were mentioned in Chapter 5.

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6

O'Driscoll, D. C. "D-branes and orientifolds in string theory." Thesis, Swansea University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638350.

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We examine the interplay of supersymmetry and compactification on D-branes and orientifold planes using the framework of superstring theory. We explore issues pertinent to geometrical descriptions of these theories and dualities among them.

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7

da, Costa M. S. "Branes and black holes in string theory." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598237.

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The goal of this thesis is to address several issues in gravitational physics, in particular black hole physics, within a quantum mechanical framework. Of course this requires the existence of such a quantum mechanical theory of gravity. Superstring theory is a consistent perturbative theory of gravity. However, many aspects of the theory turn out to be non-perturbative and in this sense the theory is still under construction. The theory of strings contains a large variety of p-dimensional spatially extended objects, now called p-branes. These p-branes are dynamical objects embedded in space-time: they interact between each other, intersect each other and bound themselves together. In this thesis I shall study some of these p-brane configurations. I shall start by using supergravity which is a large distance (low energy) approximation to string theory, to construct many new p-brane configurations. The emphasis will be on the technics to construct the supergravity solutions describing these configurations and on the symmetries of the underlying theory that render their existence. I shall not attempt to give a complete classification of the p-brane configurations folklore nor shall I address issues related to the global structure of the corresponding gravitational geometry. In turn, the focus will be on the microscopic and quantum mechanical description of some of these p-brane configurations, namely the D-brane bound states. In particular, I shall study in detail a D-5 brane configuration with a constant magnetic field on its worldvolume. The gravitational counterpart is a five-dimensional black hole. The quantum mechanical description of this system will allow the calculation of the Bekenstein-Hawking entropy from counting microscopic states of the D-brane system. The scattering of a scalar particle off the black hole (and therefore Hawking radiation) are also studied. I end by making a proposal for an effective string description of black hole dynamics. In the process I shall use results in perturbative string theory, gauge theory and gravitational theory. In this sense, this thesis is rather interdisciplinary which is a remarkable characteristic acquired by superstring theory.

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8

Vanichchapongjaroen, Pichet. "Branes and applications in string theory and M-theory." Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10552/.

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This thesis discusses branes in string theory and M-theory. In chapter 1, we present background materials. In chapters 2 and 3, we discuss an application of a D3/D7 model in the framework of gauge/gravity duality, which uses the results of a gravity theory calculation to obtain informations about the corresponding gauge theory. Gauge/gravity duality is usually studied in a non-compact space. This thesis, however, focuses on the duality in a compact space. In chapter 2, we study a strongly coupled gauge theory in a compact space. We find that a homogeneous ground state is unstable at a sufficiently large isospin chemical potential. We then construct a new ground state which corresponds to a scalar meson condensate charged under a global SO(4) symmetry. In chapter 3, we discuss an on-going work. We study a strongly-coupled gauge theory living in a compact space with a generic value of quark mass at zero temperature in the presence of an external magnetic field. We are investigating the phase diagram of the external magnetic field and quark mass. In chapter 4 and 5, we move to M-theory. In chapter 4, we construct a complete non-linear theory of a supersymmetric single M5-brane with a 3+3 splitting. The M5-brane lives in a general background of M-theory. The idea of our construction is to get equations of motion that agree with that obtained from the superembedding approach. In chapter 5, we consider a model which attempts to describe a theory on multiple M5-branes. Using this model, we construct self-dual string solutions which describes M2/M5 branes intersection. These solutions are supported by magnetic monopoles. For self-dual strings with large number of M2 and M5-branes, we obtain the required radius-distance relationship and energy.

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9

Sehmbi, Gurdeep Singh. "Branes and geometry in string and M-theory." Thesis, Durham University, 2012. http://etheses.dur.ac.uk/3900/.

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This thesis is based on two papers by the author and consists of two parts. We review the recent developments in the theory of multiple M2-branes and 3-algebras leading to multiple D2-brane theories. The inclusion of flux terms for the supersymmetric BLG and ABJM theories of closed M2-branes is discussed and then generalised to open M2-branes. Here the boundary condition is derived and different BPS configurations are examined where we find a mass deformed Basu-Harvey equation for the M2-M5 system. The Lorentzian 3-algebra is then employed for obtaining a theory of D2-branes in a flux background, we then obtain the new fuzzy funnel solution of the system of D2-D4 branes in a flux. Matrix theories and their compactifications as well as noncommutative geometry and noncommutative gauge theories are reviewed with a discussion of their generalisations to three dimensions to be used to describe the M-theory three form potential. A new feature of string theory is then obtained called the quantum Nambu geometry (QNG). It is found by considering the action for D1-strings in a RR flux background and we demonstrate that there is a large flux double scaling limit where the action is dominated by a Chern-Simons-Myers coupling term. A classical solution to this is the quantised spacetime known as the quantum Nambu geometry. Various matrix models are obtained from this action, these are the large flux dominated terms of the full actions for the corresponding matrix models. The QNG gives rise to an expansion of D1-strings to D4-branes in the IIA theory, so we obtain an action for the large flux terms for this action which is verified by a dimensional reduction of the PST action describing M5-branes. We make a generalisation of the D4-brane action to describe M5-branes using a duality. We are describing the 3-form self-dual field strength of a non-abelian generalisation of the PST action.

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10

Prezas, Nikolas 1973. "Aspects of branes and orbifolds in string theory." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8486.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 2002.
Includes bibliographical references (p. 245-268).
The main theme of this thesis is branes and orbifolds in string theory, with some digression towards other directions in the final chapters. After reviewing background material on D-branes and orbifolds, along with some mathematical fundamentals, I describe the following results. First, a classification of discrete torsion for a large class of orbifolds and a technique for extracting the matter content of D-brane probe gauge theories on orbifolds with discrete torsion. Subsequently, I discuss an algorithm, called stepwise projection, that illuminates the structure of the so-called exceptional quivers, and hints towards the brane realization of the associated gauge theories. Next, I present the computation of the partition function of the coset conformal field theory describing the two-dimensional black hole. This computation confirms earlier results concerning the spectrum of the black hole and it enable us to identify the physical Hilbert space. This theory appears in the exact string theory description of configurations of Neveu-Schwarz 5-branes and in the conformal field theory description of certain orbifolds in singular limits; thus, it is only a mild digression from the main theme of the thesis. This is not so, however, for the last topic discussed here. We will change gears completely and discuss our extension of Witten's construction of boundary string field theory to the superstring. As in the bosonic case, the main tool we use is the Batalin-Vilkovisky formalism. Our construction proves a recent conjecture regarding the spacetime action of the supersymmetric theory and a related conjecture concerning quantum field theories on two-dimensional spaces with boundaries.
by Nikolas Prezas.
Ph.D.

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11

Jia, Bei. "D-branes and K-homology." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/32039.

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In this thesis the close relationship between the topological $K$-homology group of the spacetime manifold $X$ of string theory and D-branes in string theory is examined. An element of the $K$-homology group is given by an equivalence class of $K$-cycles $[M,E,\phi]$, where $M$ is a closed spin$^c$ manifold, $E$ is a complex vector bundle over $M$, and $\phi: M\rightarrow X$ is a continuous map. It is proposed that a $K$-cycle $[M,E,\phi]$ represents a D-brane configuration wrapping the subspace $\phi(M)$. As a consequence, the $K$-homology element defined by $[M,E,\phi]$ represents a class of D-brane configurations that have the same physical charge. Furthermore, the $K$-cycle representation of D-branes resembles the modern way of characterizing fundamental strings, in which the strings are represented as two-dimensional surfaces with maps into the spacetime manifold. This classification of D-branes also suggests the possibility of physically interpreting D-branes wrapping singular subspaces of spacetime, enlarging the known types of singularities that string theory can cope with.
Master of Science

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12

Wulff, Linus. "Strings, boundary fermions and coincident D-branes." Doctoral thesis, Stockholm : Department of Physics, Stockholm University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-6576.

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13

Pawelczyk, Jacek, Soo-Jong Rey, and jacek pawelczyk@physik uni-muenchen de. "Ramond--Ramond Flux Stabilization of D--Branes." ESI preprints, 2000. ftp://ftp.esi.ac.at/pub/Preprints/esi955.ps.

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14

Wurtz, Albrecht. "Conformal Field Theory and D-branes." Doctoral thesis, Karlstad University, Faculty of Technology and Science, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-1346.

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The main topic of this doctoral thesis is D-branes in string theory, expressed in the language of conformal field theory. The purpose of string theory is to describe the elementary particles and the fundamental interactions of nature, including gravitation as a quantum theory. String theory has not yet reached the status to make falsifiable predictions, thus it is not certain that string theory has any direct relevance to physics. On the other hand, string theory related research has led to progress in mathematics.

We begin with a short introduction to conformal field theory and some of its applications to string theory. We also introduce vertex algebras and discuss their relevance to conformal field theory. Some classes of conformal field theories are introduced, and we discuss the relevant vertex algebras, as well as their interpretation in terms of string theory.

In string theory, a D-brane specifies where the endpoint of the string lives. Many aspects of string theory can be described in terms of a conformal field theory, which is a field theory that lives on a two-dimensional space. The conformal field theory counterpart of a D-brane is a boundary state, which in some cases has a natural interpretation as constraining the string end point. The main focus of this thesis is on the interpretation of boundary states in terms of D-branes in curved target spaces.

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15

Berenstein, David Eliecer. "Dynamical aspects of D-branes and matrix theory /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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16

Condeescu, Cezar. "Non-perturbative effects in string theory." Palaiseau, Ecole polytechnique, 2010. http://pastel.archives-ouvertes.fr/docs/00/56/57/62/PDF/Phd-thesis.pdf.

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On étudie les effets non-perturbatifs généré par des branes instantoniques Euclidiens en compactifications de la théorie des cordes de type I/II avec orientifolds et D-branes magnétisées. Le focus est sur les instantons qui peuvent générer des corrections au superpotentiel. Une condition nécessaire est que les instantons doivent enrouler des cycles rigides. On considère la compactification de la théorie de Type I (IIB) sur l'orientifold T^6/Z_2xZ_2 avec torsion discrète et D-branes magnétisées. Les instantons enroulant le même cycle que l'O-plane exotique (requis par la torsion discrète) ont la structure désiré de modes zéro pour générer des corrections au superpotentiel. On construit des modèles globales basée sur cet orientifold ou les instantons génère des termes linaires et de termes de masse dans le superpotentiel. En théorie des cordes on calcule un couplage physique duquel on doit extraire la partie olomorphique pour obtenir le superpotentiel non-perturbatif. Les facteurs non-olomorphiques sont absorbés dans le potentiel de Kähler et dans redéfinitions des champs chiraux et modules des cordes fermées. On a dérivé ces redéfinitions pour les compactifications toroïdales (avec orientifolds) de la théorie de Type I avec branes magnétisées et lignes Wilson. Finalement, on a considéré des modèles globales avec des termes linéaires. On a calculé explicitement le superpotentiel non-perturbatif pour les orientifolds toroïdales. On a montré comment faire la somme sur les contributions a un instanton. Les modèles analysées possédaient des vides non-perturbatifs supersymétriques ou le group de jauge était brisé et certains modules des cordes ouvertes étaient stabilisés
We study non-perturbative effects generated by Euclidean brane instantons in compactifications of Type I/II string theory with orientifolds and magnetized D-branes. The focus is on instantons which can generate corrections to the superpotential. A necessary condition is that the instantons have to wrap rigid cycles. We consider the compactification of Type I (IIB) on the T^6/Z_2xZ_2 orientifold with discrete torsion and magnetized branes. The instantons wrapping the same cycle as the exotic O-planes (required by the presence of discrete torsion) have the desired uncharged zero-mode structure in order to generate corrections to the superpotential. We build global models based on this orientifold where stringy instantons generate linear terms and mass terms in the superpotential. Typically, in string theory one computes a physical coupling from which one has to extract a holomorphic part in order to obtain the non-perturbative superpotential. Various non-holomorphic factors are absorbed into the Kähler potential and redefinitions of chiral fields and closed string moduli. We have derived these redefinitions in the context of toroidal (orientifold) compactifications of Type I with magnetized branes and continuous Wilson lines. Finally, we have considered global models with linear terms in the superpotential generated non-perturbatively. We have computed explicitly the non-perturbative superpotential for toroidal orientifolds. We show how to sum coherently over the various one-instanton contributions. The explicit models analyzed possessed a non-perturbative supersymmetric vacuum where the gauge group was broken and certain open-string moduli were stabilized

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17

Srivastava, Yogesh K. "Dynamics of black holes and black rings in string theory." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1181586688.

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18

Braun, Volker Friedrich. "K-theory and exceptional holonomy in string theory." Doctoral thesis, [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965401650.

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19

Wilshin, Simon. "Identifiable branes and their realisation in toy models of string theory." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534180.

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20

Witkowski, Lukas Thomas. "Sequestering of Kähler moduli in type IIB string theory." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:6f5c8a99-26ca-401b-ad42-7bd3bf873f80.

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In this thesis we employ string perturbation theory in toroidal orbifold models to study aspects of supersymmetry breaking in type IIB string theory. First, we determine the dependence of physical Yukawa couplings on blow-up moduli in models with D3-branes at orbifold singularities. Blow-up moduli are scalar fields describing the size of small blow-up cycles in the compactification geometry. In models implementing moduli stabilisation these fields can acquire F-terms and break supersymmetry. We examine the moduli-dependence of physical Yukawa couplings at string tree-level by computing disk correlation functions involving a Yukawa interaction of visible sector fields and an arbitrary number of blow-up moduli. We perform the calculation for one blow-up insertion explicitly and find that the correlation function vanishes if the blow-up modulus is associated with a small cycle distant to the visible sector. For more than one blow-up insertion we show that all such correlation functions are exponentially suppressed by the compactification volume. We explain how these results are relevant to suppressing soft terms to scales parametrically below the gravitino mass. Further, we determine corrections to holomorphic Yukawa couplings on D3-branes at an orbifold singularity due to non-perturbative effects such as gaugino condensation on a stack of D7-branes. This can be done by calculating a one-loop threshold correction to the gauge coupling on the D7-branes. We show that, if present, the new contributions to Yukawa couplings are not aligned with the tree-level couplings. As the new Yukawa couplings contribute to soft A-terms they are sources of flavour-changing neutral currents. Last we discuss an effect unrelated to supersymmetry breaking. We show that orbifold models with D3-branes at orbifold singularities can exhibit kinetic mixing of different massless Abelian factors. For this to be possible, the relevant U(1) factors have to be associated with more than one orbifold singularity.

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21

Dawson, Peter Dale. "Effective actions and charges of D-branes in curved space-time." Title page, abstract and contents only, 2003. http://web4.library.adelaide.edu.au/theses/09PH/09phd2727.pdf.

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Bibliography: leaves 181-190. This thesis firstly investigates K-invariant and supersymmetric actions of D-branes in curved space-time. Following this, research into charges of D-branes in a group manifold are studied. In particular, the charge groups are determined for the symmetry preserving (or untwisted) D-branes on a compact, simple, connected, simply connected group manifold. The purpose of this research is to determine these charge groups in order that they can be compared to the charge groups predicted by twisted K-theory for D-branes in a group manifold, thus providing a future important check to the theorem that D-brane charges are determined by twisted K-theory, one of the most important recent ideas in string theory.

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22

Stiffler, Kory M. "A walk through superstring theory with an application to Yang-Mills theory: k-strings and D-branes as gauge/gravity dual objects." Diss., University of Iowa, 2010. https://ir.uiowa.edu/etd/744.

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Superstring theory is one current, promising attempt at unifying gravity with the other three known forces: the electromagnetic force, and the weak and strong nuclear forces. Though this is still a work in progress, much effort has been put forth toward this goal. A set of specific tools which are used are gauge/gravity dualities. This thesis consists of a specific implementation of gauge/gravity dualities to describe k-strings of strongly coupled gauge theories as objects dual to Dpbranes embedded in confining supergravity backgrounds from low energy superstring field theory. Along with superstring theory, k-strings are also commonly investigated with lattice gauge theory and Hamiltonian methods. A k$string is a colorless combination of quark-anti-quark source pairs, between which a color flux tube develops. The two most notable terms of the k-string energy are, for large quark anti-quark separation L, the tension term, proportional to L, and the Coulombic 1/L correction, known as the Luscher term. This thesis provides an overview of superstring theories and how gauge/gravity dualities emerge from them. It shows in detail how these dualities can be used for the specific problem of calculating the k-string energy in 2+1 and 3+1 space-time dimensions as the energy of Dp-branes in the dual gravitational theory. A detailed review of k-string tension calculations is given where good agreement is found with lattice gauge theory and Hamiltonian methods. In reviewing the k-string tension, we also touch on how different representations of k-strings can be described with Dp-branes through gauge/gravity dualities. The main result of this thesis is how the Luscher term is found to emerge from the energy calculation of Dp-branes. In 2+1 space-time dimensions, we have Luscher term data to compare with from lattice gauge theory, where we find good agreement.

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23

Reimers, D. T. "Superalgebras and brane actions." University of Western Australia. School of Physics, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0045.

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The Noether charge algebra of brane actions is typically modified by a topological anomalous term. The underlying cohomology of this anomalous term is investigated, and it is shown that the anomalous term possesses a gauge freedom. The result is that the anomalous term generates a parameterized family of topological charge algebras. When fermionic charges are taken to be nonvanishing, the known algebras underlying extended superspace formulations of the action appear in these families. This phenomena is investigated for minimal p-branes, Dp-branes and (p, q)-strings. The algebras resulting from the D-brane actions are shown to allow the construction of extended superspace actions without worldvolume gauge fields. It is shown that the actions are !-symmetric, and that the symmetry is generated by a right action. The global and local symmetry transformations of the Born-Infeld gauge field are thus shown to be described geometrically by left/right actions of the underlying extended supertranslation group. An equivalence class construction is proposed for the description of compact fermionic dimensions. In this construction, open strings in extended superspace translate to closed strings in compact superspace, and fermionic topological charges may be realized by closed strings. The differential underlying the descent construction for Noether charge algebras is shown to be naturally described as a dual of the de Rham differential. The ghost fields used in the construction are shown to be described geometrically as a vielbein with respect to this differential.

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24

Miemiec, André. "Branes between geometry and gauge theory." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2000. http://dx.doi.org/10.18452/14507.

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Der Gegenstand dieser Arbeit ist Bestandteil der Stringtheorie und betrifft insbesondere die geometrischen Aspekte der Realisierung von Eichtheorien innerhalb der Stringtheorie. Wir studieren die Eichtheorie von D3-Branes an verallgemeinerten Singularitaeten wie der Orbifold- oder Conifold-Singularitaet. Die Einfuehrung der sogenannten Branediamanten fuehrt auf ein konsistentes Bild. Fuer diese Klasse von Modellen wird die Wirkung der Mirrorsymmetrie diskutiert. Im zweiten Teil untersuchen wir die Feldtheorie der M5-Brane auf der Grundlage des Supereinbettungsformalismus. Das Hauptresultat dieses Kapitels ist eine explizite Identifikation der selbstdualen 3-Form mit den Parametern der komplexen Struktur des Einbettungsraumes. Das heuristische Material, das in den vorangegangenen Kapiteln angesammelt wurde, weist darauf hin, dass die Informationen, die ein supersymmetrischer 3-Zykel enthaelt, zumindest teilweise auf supersymmetrische 2-Zykel zurueckgefuehrt werden koennen. Daher studieren wir den Fall von Brane-Boxen, die durch Ueberlagerung von gewoehnlichen N=2 Systemen aus D4 und NS5-Branes gewonnen werden koennen. Diese Konfigurationen erfuellen die Bedingung des `uniform bending' und der Lift auf einen supersymmetrischen 3-Zykel kann explizit ausgefuehrt werden. Im letzten Teil konstruieren wir eine neue superkonforme N=1 Eichtheorie, die aus einer Massendeformation der N=4 SYM entsteht und eine duale Supergravitationsbeschreibung durch die AdS/CFT-Korrespondenz besitzt.
The subject of this work is part of the theory of strings and in particular concerned with geometrical aspects of the realization of gauge theory within string theory. In particular we study the gauge theory of D3-branes at generalised singularities like orbifolds and the orbifolded conifold singularities. The introduction of the so called diamonds leads to a consistent picture. The action of mirror symmetry for this class of models is discussed. In a second part the field theory of the M5-brane will be investigated on the basis of the superembedding approach. The main result here will be a rather explicit identification of the self dual three form field with the parameters of the complex structure of the embedding space. The heuristic material collected from the previous chapters states that the information contained in supersymmetric 3-cycles can be partially extracted from supersymmetric 2-cycles. Thus we study the case of brane boxes, which can be obtained by sewing together usual N=2 setups of D4 and NS5-branes. These systems satisfy the condition of uniform bending and the lift to a supersymmetric 3-cycle can be performed explicitly. In the last part a new superconformal N=1 gauge theories will be constructed which arise as certain deformations of N=4 SYM and have a dual description due to the AdS/CFT correspondence.

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25

Krippendorf, Sven-Ludwig. "D-brane model building and moduli stabilisation in type IIB string theory." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609632.

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26

Michishita, Yoji. "D0-branes in SO(32)×SO(32)open type 0 string theory." 京都大学 (Kyoto University), 2001. http://hdl.handle.net/2433/150826.

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27

Goodsell, Mark Dayvon. "One loop phenomenology of type II string theory : intersecting d-branes and noncommutativity." Thesis, Durham University, 2007. http://etheses.dur.ac.uk/2915/.

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We examine one loop amplitudes for open and closed strings in certain D-brane configurations, and investigate the consequences for phenomenology. Initially we consider open strings at D6-brane intersections. We develop techniques for one-loop diagrams. The one-loop propagator of chiral intersection states is calculated exactly and its finiteness is shown to be guaranteed by RR tadpole cancellation. The result is used to demonstrate the expected softening of power law running of Yukawa couplings at the string scale. We also develop methods to calculate arbitrary TV-point functions at one-loop, including those without gauge bosons in the loop. These techniques are also applicable to heterotic orbifold models. One issue of the intersecting D6-brane models is that the Yukawa couplings of the simpler models suffer from the so-called "rank one" problem - there is only a single non-zero mass and no mixing. We consider the one-loop contribution of E2-instantons to Yukawa couplings on intersecting D6-branes, and show that they can provide a solution. In addition they have the potential to provide a geometric explanation for the hierarchies observed in the Yukawa couplings. In order to do this we provide the necessary quantities for instanton calculus in this class of background. We then explore how the IR pathologies of noncommutative field theory are resolved when the theory is realized as open strings in background B-fields: essentially, since the IR singularities are induced by UV/IR mixing, string theory brings them under control in much the same way as it does the uv singularities. We show that at intermediate scales (where the Selberg-Witten limit is a good approximation) the theory reproduces the noncommutative field theory with all the (un)usual features such as UV/IR mixing, but that outside this regime, in the deep infra-red, the theory flows continuously to the commutative theory and normal Wilsoman behaviour is restored. The resulting low energy physics resembles normal commutative physics, but with additional suppressed Lorentz violating operators. We also show that the phenomenon of UV/IR mixing occurs for the graviton as well, with the result that, in configurations where Planck's constant receives a significant one-loop correction (for example brane-induced gravity), the distance scale below which gravity becomes non-Newtonian can be much greater than any compact dimensions.

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28

Irie, Hirotaka. "String fields, matrix models and D-branes in (p,q) minimal superstring theory." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/136869.

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29

Pasukonis, Jurgis. "BPS operators and brane geometries." Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8614.

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In this thesis we explore the finite N spectrum of BPS operators in four-dimensional supersymmetric conformal field theories (CFT), which have dual AdS gravitational descriptions. In the first part we analyze the spectrum of chiral operators in the free limit of quiver gauge theories. We find explicit counting formulas at finite N for arbitrary quivers, construct an orthogonal basis in the free inner product, and derive the chiral ring structure constants. In order to deal with arbitrarily complicated quivers, we develop convenient diagrammatic techniques: the results are expressed by associating Young diagrams and Littlewood-Richardson coefficients to modifications of the original quiver. We develop the notion of a "quiver character", which is a generalization of the symmetric group character, obeying analogous orthogonality properties. In the second part we analyze how the BPS spectrum changes at weak coupling, focusing on the N = 4 supersymmetric Yang-Mills. We find a formal expression for the complete set of eighth-BPS operators at finite N, and use it to derive corrections to a near-BPS operator. In the third part of this thesis we move on to the strong coupling regime, where the dual gravitational description applies. The BPS spectrum on the gravity side includes D3-branes wrapping arbitrary holomorphic surfaces, a generalization of the spherical giant gravitons. Quantizing this moduli space gives a Hilbert space, which, via duality and nonrenormalization theorems, should map to the space of BPS operators derived in the weak coupling regime. We apply techniques from fuzzy geometry to study this correspondence between D3-brane geometries, quantum states, and BPS operators in field theory.

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30

Rovai, Antonin. "Emergent geometry from D-Branes." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209425.

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In this thesis, we explain and illustrate on several examples how to derive supergravity solutions by computing observables in the corresponding dual, lower-dimensional field theory.

In particular, no a priori knowledge on the gravitational dual is assumed, including its dimensionality. The basic idea to construct the pre-geometric models is to consider the world-volume theory of probe D-branes in the presence of a large number N of higher-dimensional background branes. In the standard decoupling limit, the probes are moving only in the flat directions parallel to the background D-branes. We show however that the quantum effective action of the probe world-volume theory, obtained at large $N$ using standard vector model techniques, has the required field content to be interpreted as the action describing the probes in a higher-dimensional, curved and classical spacetime. The properties of the emerging supergravity solution are easily found by comparing the quantum effective action of the pre-geometric model with the non-abelian D-brane action. In all the examples we consider, this allows us to derive the metric, the dilaton and various form fields, overall performing exclusively field theoretic computations.

The first part of the thesis consists of introductory chapters, where we review vector models at large N, aspects of brane physics in supergravity and string theory and the gauge/gravity correspondence. The second part contains the original contributions of this thesis, consisting of various explicit emergent geometry examples.

Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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31

Quella, Thomas. "Asymmetrically gauged coset theories and symmetry breaking D-branes." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2003. http://dx.doi.org/10.18452/14909.

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Auf sehr kleinen Längenskalen erlaubt die Weltflächenbeschreibung über zweidimensionale konforme Feldtheorien eine störungstheoretische Definition der String-Theorie. Viele strukturelle Eigenschaften und phänomenologische Implikationen der letzteren können mit Hilfe von D(irichlet)-Branen untersucht werden, die in der zugrunde liegenden Weltflächentheorie durch konforme Randbedingungen beschrieben werden. Etliche interessante Hintergründe für die String-Theorie erhält man über Gruppenmannigfaltigkeiten und Coset-Modelle. Neben wichtigen Beispielen wie SL(2,R), SU(2) und Gepner-Modellen, die für AdS- und Calabi-Yau-Kompaktifizierungen eine Rolle spielen, beinhalten sie außerdem weitere Beispiele wie den Nappi-Witten-Hintergrund oder den Raum T^11, die über eine asymmetrische Wirkung der Eichgruppe definiert sind und eine kosmologische Raumzeit mit Urknall- und Weltsturz-Singularitäten bzw. die Basis des Conifolds beschreiben. Die vorliegende Arbeit bietet eine umfassende, auf den exakten Methoden der konformen Feldtheorie beruhende Analyse von asymmetrischen Coset-Modellen. Wegen der heterotischen Natur der zugrundeliegenden Symmetriealgebra erlauben diese Modelle nur Randbedingungen, die einen Teil der Symmetrie brechen. Nach einer allgemeinen Erläuterung der Grundidee für die Konstruktion von symmetriebrechenden Randbedingungen richtet sich das Hauptaugenmerk auf WZNW- und asymmetrische Coset-Modelle, die das Fundament nahezu aller bekannten konformen Feldtheorien bilden. Mit Hilfe der erzielten Ergebnisse werden die Struktur sowie die Geometrie von D-Branen in den Gruppen SL(2,R) und SU(2), im Hintergrund AdS_3 x S^3, in der kosmologischen Nappi-Witten-Raumzeit und in T^pq-Räumen untersucht. Die Techniken, die in dieser Arbeit entwickelt werden, erlauben jedoch ebenso die Behandlung von Rändern und Kontaktstellen in (1+1)- oder 2-dimensionalen kritischen Systemen, die in der Festkörpertheorie oder der statistischen Physik auftreten. Insbesondere können Defektlinien beschrieben werden, die weder totale Reflexion noch völlige Transmission aufweisen.
At very small length scales, the world sheet approach in terms of two-dimensional conformal field theories provides a perturbative definition of string theory. Many structural properties and phenomenological implications of the latter can be explored using D(irichlet)-branes which may be identified with conformal boundary conditions in the underlying world sheet theory. Several interesting backgrounds in string theory arise from group manifolds and coset theories. Apart from prominent examples such as SL(2,R), SU(2) and Gepner models which play a role in AdS and Calabi-Yau compactifications, they also include further instances like the Nappi-Witten background or the space T^11 which are constructed using an asymmetric action of the gauge group and which describe a cosmological space-time with big-bang and big-crunch singularities and the base of the conifold, respectively. The present thesis provides a comprehensive analysis of asymmetric cosets based on the exact methods of boundary conformal field theory. Due to the heterotic nature of the underlying symmetry algebra, the models only allow for conformal boundary conditions which break parts of the bulk symmetry. The universal ideas for the construction of symmetry breaking boundary conditions are indicated and applied in detail to WZNW and asymmetric coset theories which provide the basic building blocks of almost all known conformal field theories. The general results are used to investigate the structure and shape of D-branes in the group manifolds SL(2,R) and SU(2), the background AdS_3 x S^3, the cosmological Nappi-Witten space-time and T^pq-spaces. The techniques developed in this thesis also allow for a treatment of boundaries and junctions in (1+1)- or 2-dimensional critical systems in condensed matter theory and statistical physics. In particular, they enable us to describe defect lines which go beyond full reflection or transmission.

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32

Mayes, Van Eric. "Phenomenology of heterotic and type II orientifold string models." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1597.

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33

Closset, Cyril. "Studies of fractional D-branes in the gauge/gravity correspondence & flavored Chern-Simons quivers for M2-branes." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210125.

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Cette thèse intitulée « Studies of fractional D-branes in the gauge/gravity correspondence & Flavored Chern-Simons quivers for M2-branes » se place dans le cadre de la théorie des cordes, en physique théorique. Elle consiste en une introduction suivie de deux parties. Dans l'introduction sont résumés les différents outils de théorie des cordes qui seront utilisés.

\
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34

Björnsson, Jonas. "Strings, Branes and Non-trivial Space-times." Doctoral thesis, Karlstad University, Faculty of Technology and Science, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-1619.

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This thesis deals with different aspects of string and /p/-brane theories. One of the motivations for string theory is to unify the forces in nature and produce a quantum theory of gravity. /p/-branes and related objects arise in string theory and are related to a non-perturbative definition of the theory. The results of this thesis might help in understanding string theory better. The first part of the thesis introduces and discusses relevant topics for the second part of the thesis which consists of five papers.

In the three first papers we develop and treat a perturbative approach to relativistic /p/-branes around stretched geometries. The unperturbed theory is described by a string- or particle-like theory. The theory is solved, within perturbation theory, by constructing successive canonical transformations which map the theory to the unperturbed one order by order. The result is used to define a quantum theory which requires for consistency d = 25 + p dimensions for the bosonic /p/-branes and d = 11 for the supermembrane. This is one of the first quantum results for extended objects beyond string theory and is a confirmation of the expectation of an eleven-dimensional quantum membrane.

The two last papers deal with a gauged WZNW-approach to strings moving on non-trivial space-times. The groups used in the formulation of these models are connected to Hermitian symmetric spaces of non-compact type. We have found that the GKO-construction does not yield a unitary spectrum. We will show that there exists, however, a different approach, the BRST approach, which gives unitarity under certain conditions. This is the first example of a difference between the GKO- and BRST construction. This is one of the first proofs of unitarity of a string theory in a non-trivial non-compact space-time. Furthermore, new critical string theories in dimensions less then 26 or 10 is found for the bosonic and supersymmetric string, respectively.

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35

Smedbäck, Mikael. "Topics on D-branes and Holography." Doctoral thesis, Uppsala University, Department of Theoretical Physics, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4478.

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We discuss various aspects of D-branes in string theory and holography in string theory and loop quantum gravity.

One way to study D-branes is from a microscopic perspective, using conformal field theory techniques. For example, we investigate the question of how D-branes can be introduced into orbifolded theories. Another way to study D-branes is from a space-time perspective. An example is provided by unstable D-branes, where we compute an effective action describing the decay of a bosonic D-brane.

The holographic principle is a proposed duality which suggests that a theory in any region has a dual description on the boundary. We explore two examples: (1) The area law for the entropy of a black hole in the framework of loop quantum gravity, related to particular regularizations of the area operator. (2) The AdS/CFT correspondence proposal, where we investigate a string pulsating on AdS using spin chains.

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36

Rajan, Peter. "Spin-offs from Stretching a Point : Strings, Branes and Higher Spin." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4521.

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37

Mattiello, Luca [Verfasser], and Ivo [Akademischer Betreuer] Sachs. "On instantons and finite-size D-Branes in string theory / Luca Mattiello ; Betreuer: Ivo Sachs." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2019. http://d-nb.info/1196968578/34.

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38

Bevilaqua, Leandro Ibiapina. "\"Branas em supergravidade\"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-29032007-211600/.

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Este trabalho tem o objetivo de rever a obtenção das soluções do tipo brana em supergravidade e contém uma dedução detalhada das soluções extrema e negra. A fim de motivar algumas escolhas feitas ao longo do cálculo, o trabalho inclui uma breve revisão dos conceitos advindos da teoria de cordas e supersimetria. Esta revisão nos permitirá ainda relacionar as soluções da supergravidade com as branas da teoria de cordas e tecer considerações sobre o papel desta relação na dualidade entre teoria de calibre e gravitação.
This work intends to review the brane solutions of supergravity and contains a datailed deduction of the extremal and black solutions. In order to provide some motivations to the choices through the calculation, this work includes a brief review of some concepts from string theory and supersymmetry. This review will enable us to relate the supergravity solutions to string theory\'s branes and to make considerations about the role of this relationship in the duality between gauge and gravity theories.

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39

Ecker, Jill [Verfasser]. "Type IIA string theory on T 6/(Z2 × Z6 × OmegaR) : Model building and string phenomenology with intersecting D6-branes / Jill Ecker." Mainz : Universitätsbibliothek Mainz, 2016. http://d-nb.info/1110986408/34.

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40

Görlich, Lars. "N = 1 and non-supersymmetric open string theories in six and four space-time dimensions." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2003. http://dx.doi.org/10.18452/14978.

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Die vorliegende Arbeit beinhaltet ein einführendes Kapitel über Orbifold-Konstruktionen in dem neben rudimentären Grundlagen bereits speziellere Themen wie Diskrete Torsion und asymmetrische Orbifold-Gruppen behandelt werden. Als Beispiele für Orbifolde werden Kompaktifizierungen auf Tori sowie das asymmetrische T^4/Z(3)^L x Z(3)^R Orbifold behandelt. Danach wird eine allgemein gehaltene Einführung in Orientifolde gegeben, einschließlich des offenen String Sektors samt Chan-Paton Freiheitsgraden. Die darauf folgenden Kapitel 4-7 behandeln von mir durchgeführte Forschungsarbeiten. Kapitel 4 beschäftigt sich mit der Quantisierung des offenen Strings mit linearen Randbedingungen, wie sie bei Strings in elektro-magnetischen Feldern auftreten. Weiterhin wird die Quantisierung der Null- und Impuls-Moden des offenen Strings in Torus-Kompaktifizierungen durchgeführt. Außerdem wird für den Fall allgemeiner konstanter Hintergrund Neveu-Schwarz U(1)-Hintergrundfelder der Kommutator der Stringkoordinaten berechnet. Dieser stützt bisherige Resultate zur Nicht-Kommutativität von offenen Stringtheorien in Neveu-Schwarz Hintergründen. Kapitel 5 gibt, zusammen mit einigen neuen Erkenntnissen, Resultate von [1] über asymmetrische Orientifolde, insbesondere deren D-Branen Inhalt wieder. Kapitel 6 faßt die Veröffentlichung [2] zusammen, in der untersucht wurde, inwieweit sich phänomenolgisch interessante Modelle in Orientifolden von Torus-Kompaktifizierungen finden lassen. Insbesondere tragen die D9-Branen magnetische Flüsse, womit chirale Fermionen im Spektrum auftreten. Die Rechnungen werden größtenteils im gleichwertigen, T-dualen Bild ausgeführt. In diesem ist die Anzahl der chiralen Fermionen durch die topologische Schnittzahl der D-Branen gegeben. Existieren auf Torus-Kompaktifizierungen entweder nur nicht-chirale oder nicht-supersymmetrische Modelle, so lassen sich auf gewissen Orbifolden beide Eigenschaften miteinander vereinbaren. Kapitel 7 behandelt das "sigma Omega"-Orientifold auf einem T^6/Z(4) Orbifold. Als besonders interessantes Beispiel wird ein supersymmetrisches U(4) x U(2)^3_L x U(2)^3_R Modell vorgestellt, daß durch Einschalten geeigneter Hintergrundfelder in der effektiven Niederenergie-Wirkung auf ein Modell gebrochen wird, daß dem MSSM (minimalem supersymmetrischen Standard Modell) sehr ähnlich ist. Dieses Kapitel basiert auf unserer Publikation [3]. Ferner ist der Arbeit ein Anhang beigefügt, der einige der verwendeten Formeln sowie Beweise zu zwei Sätzen enthält, die im Text verwendet wurden.
This thesis contains an introductory chapter on orbifolds. Besides rudimentary basics we discuss more advanced topics like discrete torsion and asymmetric orbifold groups. As examples we investigate torus compactifications and an asymmetric T^4/Z(3)^L x Z(3)^R orbifold. The following chapter explains the foundations of orientifolds, including open strings with Chan-Paton degrees of freedom. Chapters 4-7 present own research. In chapter 4 we quantize open strings with linear boundary conditions, as they show up in electro-magnetic fields. We quantize the zero- and momentum-modes for toroidal compactifications, too. As an application we calculate the commutator of the coordinate fields in the case of general constant Neveu-Schwarz U(1)-field strengths. Thereby we confirm previous results on non-commutativity of open string theories in Neveu-Schwarz backgrounds. Chapter 5 reviews the results of a former publication [1] on asymmetric orientifolds, supplemented by some recent insights in connection with the preceeding chapter. Chapter 6 is a summary of [2]. In this publication we investigated to what extend one can build phenomenologically interesting models from toroidal orientifolds. By turning on magnetic fluxes on D9-branes we induce chiral fermions. Most calculations are performed in an (equivalent) T-dual picture. Here the number of chiral fermions is given by the topological intersection number of D-branes. In orientifolds of toroidal compactifications one obtains either non-chiral or non-supersymmetric orientifold solutions. However both properties can be reconciled in orientifolds that are obtained from specific supersymmetric orbifold compactifications. In chapter 7 we present the "sigma Omega"-Orientifold on a T^6/Z(4) orbifold. As a very attractive example we investigate a supersymmetric U(4) x U(2)^3_L x U(2)^3_R model that is broken to an MSSM-like model by switching on suitable background fields in the low energy effective action. This chapter is based on our publication [3]. The thesis is supplemented by an appendix with formulas applied in the text, as well as proofs to two theorems that were used as well.

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41

Zavala, Carrasco Erica Ivonne. "Brane cosmology aspects of string theory." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619911.

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42

Ott, Tassilo. "Aspects of stability and phenomenology in type IIA orientifolds with intersecting D6-branes." Doctoral thesis, [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968772889.

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43

Fredenhagen, Stefan. "Dynamics of D-branes in curved backgrounds." Doctoral thesis, [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965704017.

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44

Copland, Neil Barclay. "Aspects of M-theory brane interactions and string theory symmetries." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613011.

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45

Breckenridge, Jason C. "Black holes and Dirichlet branes in the theory of strings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ36960.pdf.

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46

Kristiansson, Fredric. "Torn, Spun and Chopped : Various Limits of String Theory." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3930.

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47

Tallarita, Gianni. "Aspects of brane world-volume dynamics in string theory." Thesis, Queen Mary, University of London, 2012. http://qmro.qmul.ac.uk/xmlui/handle/123456789/2535.

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This thesis investigates the non-abelian dynamics of D-Brane systems in String Theory, specifically focussing on the fate of the open string Tachyon. Starting from the action of two coincident non-BPS D9-branes, we investigate kink configurations of the U(2) matrix tachyon field, considering both symmetrised (Str) and conventional (Tr) prescriptions for the trace over gauge indices of the non-BPS action. Non-abelian tachyon condensation in the theory with Tr prescription, and the resulting fluctuations about the kink profile, are shown to give rise to a theory of two coincident BPS D8-branes. Next we investigate magnetic monopole solutions of the non-abelian Dirac- Born-Infeld (DBI) action describing two coincident non-BPS D9-branes in flat space. These monopole configurations are singular in the first instance and require regularization. We discuss a suitable non-abelian ansatz which describes a pointlike magnetic monopole and show it solves the equations of motion to leading order in the regularization parameter. Fluctuations are studied and shown to describe a codimension three BPS D6-brane, a formula is derived for its tension. Finally, we investigate the dynamics of a pair of coincident D5 branes in the background of k NS5 branes. We extend Kutasov's original proposal to the nonabelian case of multiple D-Branes and find that the duality still holds provided one promotes the radial direction to a matrix valued field associated with a nonabelian geometric tachyon and a particular parametrization for the transverse scalar fields is chosen. Analytic and numerical solutions for the pair's equations of motion are found in certain simplified cases in which the U(2) symmetry is broken to U(1) U(1). For certain range of parameters these solutions describe periodic motion of the centre of mass of the pair bouncing off a finite sized throat whose minimum size is limited by the D5 branes separation.

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48

Ghosh, Rhea. "On intersecting 2-brane solutions in Type IIA supergravity theory /." Connect to online version, 2005. http://ada.mtholyoke.edu/setr/websrc/pdfs/www/2005/123.pdf.

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49

Moskovic, Micha. "Holographic backgrounds from D-brane probes." Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209307.

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The gauge/string correspondence provides a non-perturbative definition of string theory and hence quantum gravity in some backgrounds, making it possible to translate statements about strongly coupled quantum field theories into results about gravity.

In this thesis, we focus on the derivation of holographic backgrounds from the field theory, without using any supergravity input. Instead, we rely crucially on the addition of probe D-branes to the stack of D-branes generating the background.

From the field theory description of the probe branes in the presence of the background branes, one can compute an effective action for the probes (in a suitable low-energy/near-horizon limit) by integrating out the background branes. Comparing this action with the D-brane probe action in a generic supergravity background then allows to determine the holographic background dual to the considered field theory vacuum.

In the first part, the required pre-requisites of field and string theory are recalled and this strategy to derive holographic backgrounds is explained in more detail on the basic case of D3-branes in flat space probed by a small number of D-instantons.

The second part contains the original results of this thesis, obtained by applying this strategy to several specific examples. We first derive the duals to three continuous deformations (Coulomb branch, β and non-commutative deformations) of the basic case, in the limit in which the D-instantons can probe the full geometry. We then derive the enhançon mechanism in a dual to a simple N=2 quiver gauge theory by using a fractional D-instanton as a probe and exploiting recent exact results on the Coulomb branch of N=2 quivers.

Finally, we obtain the near-horizon D4-brane geometry by probing the D4-branes with a small number of D0-branes.

Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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50

Jusinskas, Renann Lipinski. "Supercordas e Aspectos da Correspondência AdS/CFT." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-14102010-151117/.

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Este é um trabalho de revisão. Os principais formalismos no desenvolvimento da teoria de cordas são introduzidos e discutidos: a corda bosônica e as supercordas no formalismo de Ramond-Neveu-Schwarz e no formalismo de Green-Schwarz. São introduzidas também as açôes efetivas no limite de baixas energias das D-branas (ação DBI) e das teorias de supergravidade (D=10,11). Por fim, são analisados alguns aspectos da correspondência AdS/CFT, enunciando a conjectura e introduzindo algumas das entradas do dicionário. Os apêndices contêm tópicos de grande relevância para o texto e podem ajudar a esclarecer vários raciocínios e passagens ao longo do mesmo.
This is a review work. The main formalisms on the development of string theory are introduced and discussed: the bosonic string and the superstrings formalisms of Ramond-Never-Schwarz and Green-Schwarz. The effective actions in the low energy limit of the D-branes (DBI action) and supergravity theories (D=10,11) are introduced as well. Finally, some aspects of the AdS/CFT correspondence are analised, enunciating the conjecture and introducing some entries of the dictionary. The appendices contains some topics that are highly relevant for the whole text and may help clarify several ideas and arguments through it.

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