Motivated by the Klebanov-Polyakov conjecture we investigate the O(N) vector model at large N on a squashed three-sphere and its holographic relation to bulk gravity on asymptotically locally AdS4 space. We present analytical results for the action of the field theory as the squashing parameter , alpha→ -1, when the boundary becomes effectively one dimensional. In this limit we solve the theory exactly and show that the action of the boundary theory scales as ln(1 + alpha)/(1 + alpha)[2] which is to be compared and contrasted with the -1/(1 + alpha)[2] scaling of gravity in AdS-Taub-NUT space. These results are consistent with the numerical evidence presented in hep- th/0503238, and the soft logarithmic departure is interpreted as a prediction for the contribution due to higher spin fields in the bulk AdS[4] geometry. We then give an introduction to non relativistic AdS/CFT and numerically compute the inter quark potential in the non relativistic theory obtained by taking the DLCQ of N = 4 SYM theory by considering Wilson loops in the dual string theory via the AdS/CFT correspondence.

Orientador: Nathan Jacob Berkovits / Banca: Victor de Oliveira Rivelles / Banca: Galen Mihaylov Sotkov / Resumo: Será feita uma revisão acerca das simetrias da teoria de corda bosônica e suas anomalias. Este estudo será feito tanto para o caso de cordas movendo-se num espaço-tempo tipo Minkowski, como no caso de cordas acopladas a campos tomando valores no espaço-tempo. Usando teoria de perturbações, será calculada a condição de cancelamento de anomalia a 1-loop. Esta condição estabelecerá vinculos interessantes entre os campos do espaço tempo através de uma equação do tipo da equação de Einstein. Finalmente, será mostrado como calcular condições de cancelamento de anomalia a ordens mais altas em teoria de perturbações usando métodos do grupo de renormalização / Abstract: A review will be made of the symmetries and the anomalies of the bosonic string. It will be considered the case of a string moving in a Minkowskian space- time and also, a string coupled to fields in space-time. Perturbation theory will allow calculation at the one-loop levei of the condition under which the anomaly vanishes. This condition will establish interesting constraints on the background fields since they obey an equation of the Einstein type. Finally, it will be shown how to calculate conditions for anomaly vanishing beyond the one-loop order using renormalization group methods / Mestre

Orientador: Nathan Jacob Berkovits / Banca: Horatiu Nastase / Banca: Andrei Mikhailov / Banca: Victor de Oliveira Rivelles / Banca: Vladimir Perchin / Resumo: Esta tese é baseada em parte do meu trabalho de doutoramento e tem como objetivo apresentar uma análise detalhada de algumas propriedades recém abordadas do fantasma b composto no formalismo de espinores puros. Primeiramente será feita uma revisão dos formalismos mínimo e não-mínimo. Em seguida, será apresentada a construção do fantasma b passo a passo, inlcuindo correções quânticas. Por fim, serão estudadas em detalhes suas propriedades fundamentais, ue vão desde a nilpotência até a definição de um possível conjugado, o fantasma c / Abstract: This thesis is based in part of my work during the Ph.D. and aims to present a detailed analysis of some newly studied properties of the composite non-minimal pure spinor b ghost. First, a review of the minimal and non-minimal pure spinor formalisms will be presented. Then, the construction of the non-minimal b ghost will be done step-by-step, including quantum corrections. Finally, some of its fundamental properties will be studied i detail, ranging from nilpotency until the definition of a possible canonical conjugate, the c ghost / Doutor

The linearized Einstein equation describing graviton propagation through a chiral medium appears to be helicity dependent. We analyze features of the corresponding spectrum in a collision-less regime above a flat background. In the long wave-length limit, circularly polarized metric perturbations travel with a helicity dependent group velocity that can turn negative giving rise to a new type of an anomalous dispersion. We further show that this chiral anomalous dispersion is a general feature of polarized modes propagating through chiral plasmas extending our result to the electromagnetic sector.

We replaced the classical string theory notions of parameter space and world-time with noncommutative tori and consider maps between these spaces. The dynamics of mappings between different noncommutative tori were studied and a noncommutative generalization of the Polyakov action was derived. The quantum torus was studied in detail as well as *-homomorphisms between different quantum tori. A finite dimensional representation of the quantum torus was studied and the partition function and other path integrals were calculated. At the end we proved existence theorems for mappings between different noncommutative tori. / Dissertation (MSc)--University of Pretoria, 2012. / Physics / unrestricted

Intonation is one of the most important issues facing performers of string quartets. Often, string students learn to play in tune strictly in terms of their own melodic line. To play in tune in a string quartet requires an understanding of the underlying harmony and how intonation can be fluid and flexible in an ensemble. This paper offers students an introduction to harmonic intonation and provides exercises to put this knowledge into practice. The text begins with instruction and exercises related to perfect intervals, which form the basis for intonation. Next, consonant intervals are discussed along with exercises for practice and ear training. Chords are constructed and practiced upon the basis of this interval practice. Student quartets are then asked to play excerpts from the repertoire presented as harmonic reductions and as originally written in order to connect the theoretical knowledge to the string quartet repertoire. Finally, chorales by J.S. Bach arranged for string quartet are provided for continuing practice of intonation in tonal harmony. It is not the attempt of this project to teach music theory or present a comprehensive study of the many issues and challenges related to intonation in string quartet playing. The aim of this essay is to provide students with a solid foundation and practical application of basic principles of playing in tune in a string quartet.

The problem of this study was to investigate the resilient effects of selected string tensions in various types of tennis rackets. The rackets selected were the Wilson T-2000, Head Professional, Head Master, Dunlop Fort, Dunlop Austral, and Yamaha Composite. Each racket was randomly strung and tested at 45, 52.5, and 60 pounds of string tension. The testing involved dropping a tennis ball 100 inches onto the racket face, which was stationary, and measuring the height of the ball bounce. The data collected from the rackets and string tensions were analyzed by the analysis of variance and the .05 level of confidence was used to determine significance. A significant difference occurred between the Head Professional and Wilson T-2000 and the Head Professional and Yamaha Composite. Significant differences occurred between all three string tensions.

In this thesis, compactifications of F-theory on six dimensional symmetric toroidalorbifolds are explored. These orbifold geometries have been mathematically classified and it is natural to ask what the physical implications of string theorycompactifications on those geometries are. Since compactifications of string theory to six dimensions describe a sweet spot in terms of developed methods andrich model-building possibilities, it is interesting to investigate the landscape ofthese theories opposed to the swampland of only apparently consistent quantumtheories of gravity. Additionally, superconformal field theories can exist in at mostsix dimensions. These emerge naturally in the considered F-theory constructions. The present work explores effects of compactifications on such orbifolds buildingon the work of [arXiv:1905.00116v1 [hep-th]]. It constitutes a step towards extendingthe geometric classification of these orbifolds to a classification of the physical models. Beyond [arXiv:1905.00116v1 [hep-th]], roto-translations have severe effects on thegeometry and thus the field theory and the spectrum. These effects are discussedin this thesis and include, amongst others, twisted affine folding of gauge groups, the emergence of superconformal points away from intersecting branes as well assuperconformal sectors related to the multiple fibre. / In dieser Thesis werden Kompaktifizierungen von F-Theorie auf sechs dimensionalen symmetrischen, toroidalen Orbifaltigkeiten untersucht. Da diese Orbifaltigkeiten mathematisch klassifiziert wurden, stellt sich auf natürliche Weisedie Frage nach den physikalischen Implikationen von Kompaktifizierungen vonString Theorie auf diesen. In Kompaktifizierungen von String Theorie zu sechs Dimensionen balancieren sich der Fortschritt der Methoden und die Möglichkeitenphysikalische Theorien zu modellieren optimal. Daher ist es wichtig das "Landscape" dieser Theorien zu untersuchen, im Gegensatz zu dem so genannten "Swampland" von vermeintlich konsistenten Quantentheorien der Gravitation. Darüber hinaus stellt sich heraus, dass superkonforme Feldtheorien höchstens insechs Dimensionen existieren können. Die vorliegende Arbeit erkundet die Effekte von Kompaktifizierungen auf solchen Orbifaltigkeiten aufbauend auf der Arbeit von [arXiv:1905.00116v1 [hep-th]]. Sie stellt einen wichtigen Schritt dar auf dem Weg zu einer Ausweitung der geometrischen Klassifikation dieser Orbifaltigkeiten zu einer Klassifikation der physikalischen Modelle. Über [arXiv:1905.00116v1 [hep-th]] hinaus resultieren Roto-Translationen in Effekten auf die Feldtheorie sowie deren Spektrum. Diese Effekte werden in dieser Thesis diskutiert. Beispiele reichen von getwisteten affinen Faltungen von Eichgruppen, zu dem Auftreten von superkonformen Punkten ohne sich schneidende Branen und superkonforme Sektoren in Verbindung mit dem "mehrfach Faser"-Phänomen. / <p>This thesis was conducted under the regulations of Heidelberg University under the joint supervision of Professor Luca Amendola (University of Heidelberg) and Assistant Professor Magdalena Larfors (Uppsala University) during a one-year ERASMUS-exchange.</p>

Repository copy includes the score of 16 pages, including 1 page of performance instruction, in a pdf format from the original, edited in Sibelius 8.2.0. / Barzakh means separation in Arabic. Moreover, in the Islamic eschatology, it is a barrier between the physical and spiritual worlds. In this piece, I am using this idea as an inspiration to my creation so that a disrupting sound and its developments are separating the sound worlds and opening new dimensions for new musical spaces. The piece is composed for string quartet and its duration is approximately 9 minutes.

The problem involved in this project is the composition of a series of selections for string ensemble. The series is comprised of five sections, each to parallel general achievement of the string students at the end of each year for five years. The degree of advancement one year over another is based not upon the slow student, nor the student who learns extremely fast. Nor is it graded to meet achievement of students who have been afforded a large amount of private instruction over the five years. Rather, it is based upon the growth and development, as observed by the writer, in a group of students of the Ogden City Schools. The writer believes that this would be typical of youngsters in other systems. Also, it is generally agreed upon by string music educators that a group of violins will reach a higher degree of proficiency over a given period of time than will the lower strings, viz., cellos and string basses. This fact has been kept in mind in the writing of these ensembles.