Spelling suggestions: "subject:"superstructure theories.""
1 |
Cosmic superstrings and bimetric gravityRajamanoharan, Senthooran January 2012 (has links)
No description available.
|
2 |
The crumpling transition in four dimensionsStillwell, William Schell 01 January 1998 (has links)
No description available.
|
3 |
Duality and extended geometry in string theory and M-theoryBlair, Christopher David Andrew January 2015 (has links)
No description available.
|
4 |
Anomalies and symmetries of M-theory /Ruchayskiy, Oleg M. January 2003 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Physics, December 2003. / Includes bibliographical references. Also available on the Internet.
|
5 |
Superstrings : topology, geometry and phenomenology and astrophysical implications of supersymmetric modelsGreene, Brian Randolph January 1986 (has links)
Much of the low energy phenomenology which can be extracted from the field theory limit of the intrinsically ten dimensional E 8 ® E 8 heterotic superstring depends upon the topological and geometrical properties of the six dimensional compactified component of spacetime. After briefly reviewing the topological constraints on the latter manifold which ensure the survival of N=l four dimensional supersymmetry, we present and apply the mathematics necessary for the rigorous construction of vacuum solutions and the determination of the four dimensional massless field content. Two phenomenologically attractive classes of solutions, with unbroken E<sub>8</sub> ⨂ SU(5) and E<sub>8</sub> ⨂ SO(10) gauge groups, arise if the vacuum configuration contains a Ricci flat Kahler manifold with SU(3) holonomy (Calabi-Yau manifold), which admits certain SU(5) or SU(4) vector bundles. Further reduction of the gauge group and emergence of naturally light weak Higgs doublets may also occur by flux breaking if the Calabi Yau manifold is multiply connected. We analyse the feasibility of such scenarios for Calabi Yau manifolds with any possible fundamental group. Phenomenological considerations place severe constraints on the dimensions and transformation properties of certain cohomology groups and thereby lead to a highly restricted class of acceptable models. We then present the mathematical analysis of a three generation heterotic superstring inspired model, with E<sub>8</sub> ⨂ E<sub>6</sub> gauge symmetry. A detailed description of the manifold of compactification is given, along with a determination of its Hodge numbers and of the associated light supermultiplet structure. For a particular choice of vacuum moduli we derive this manifold's symmetry group, and determine its action on the massless fields in the theory. Preliminary investigation indicates that these transformation properties give rise to a remarkably realistic model. In the second volume we derive cosmological constraints on a supersymmetric extension of the standard model in which weak gauge symmery breaking is triggered at the tree level by a Higgs singlet superfield. The fermionic component of this gauge singlet (the "nino") is shown to be the lightest supersymmetric particle with a relic abundance near the critical closure density for a surprisingly wide range of the unconstrained parameters. The previously favoured photino dark matter scenario has been eliminated by the non observation of high energy solar neutrinos. After briefly reviewing this argument, we extend the analysis to eliminate Higgsino dark matter scenarios with and#60H<sub>1</sub>°and#62 ≠ and#60H<sub>2</sub>°and#62. We show that the nino produces an acceptably low level of solar neutrinos and that it may also account for the anomalously high level of cosmic ray antiproton flux.
|
6 |
Warped throat geometries and low-energy spectrum of confining gauge theoriesMelnikov, Dmitry. January 2008 (has links)
Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Physics and Astronomy." Includes bibliographical references (p. 92-96).
|
7 |
Topics in flux compactifications of type IIA superstring theoryIhl, Matthias, 1977- 03 June 2010 (has links)
Realistic four-dimensional model building from string theory has been a focus of the string theory community ever since its inception. Toroidal orientifold constructions have emerged as a technically simple class of candidate models. Novel ingredients, such as background fluxes, have been discovered and intensely studied over the past few years. They allow for a (partial) solution of several long standing problems associated with model building in this framework. In this thesis, I summarize progress
that has been made in toroidal orientifold constructions in type IIA string theory.This includes a detailed discussion of moduli stabilization and (non-) supersymmetric AdS and Minkowski vacua. Furthermore I commence a systematic study of generalized NSNS, i.e., metric and non-geometric, fluxes. The emergence of novel D-terms is presented in detail. While most of the discussion applies to generic orientifolds of T⁶, most features are exemplified by and studied in terms of a certain orientifold of T⁶/ℤ₄ owing to its somewhat richer structure compared to simpler models studied before. It is also briefly reported on efforts of finding de Sitter vacua and inflation in this class of models. / text
|
8 |
A study of giant graviton dynamics in the restricted schur polynomial basisDe Comarmond, Vincent 07 October 2011 (has links)
MSc., Faculty of Science, University of the Witwatersrand, 2011 / Anomalous dimensions are calculated for a certain class of operators in the restricted
Schur polynomial basis in the large N limit. A new computationally
simple form of the dilatation operator is derived and used in this dissertation.
The class of operators investigated have bare dimension of O(N). Thus the calculation
necessarily sums non-planar Feynmann diagrams as the planar approximation
has broken down for operators of this size. The operators investigated
have two long columns and the operators mix under the action of the dilatation
operator, however the mixing of operators having a different number of columns
is suppressed and can be neglected in the large N limit. The action of the one
loop dilatation operator is explicitly calculated for the cases where the operators
have two, three and four impurities and it is found that in a particular limit
the action of the one loop dilatation operator reduces to that of a discrete second
derivative. The lattice on which the discretised second derivative is defined
is provided by the Young tableaux itself. The one loop dilatation operator is
diagonalised numerically and produces a surprisingly simple linear spectrum,
with interesting degeneracies. The spectrum can be understood in terms of
a collection of harmonic oscillators. The frequencies of the oscillators are all
multiples of 8g2Y
M and can be related to the set of Young tableaux acted upon
by the dilatation operator. This equivalence to harmonic oscillators generalises
on previously found results in the BPS sector, and suggests that the system is
integrable. The work presented here is based primarily on research carried out
by R.de Mello Koch, V De Comarmond, and K. Jefferies in [1].
|
9 |
Two scale compactification of the E(8)xE(8) heterotic string / 2 scale compactification of E(8)xE(8) heterotic string.Walton, Mark, 1960- January 1987 (has links)
A simple two scale compactification scheme for the E(8) x E(8) heterotic string is studied. The internal space used is a direct product of two compact spaces, each with its own length scale. Compactification on the smaller 4-dimensional (4d) manifold is carried out to obtain 6d theories with simple supersymmetry (SUSY). Assuming the background torsion vanishes, we show that this manifold must be K3. Compactification on K3 is studied in detail. Also analyzed are the two possible torsion-free compactifications on the orbifold K3$ sp prime$ (the limit of the manifold K3). The compactification from 6d to 4d on the larger scale 2d manifold results in Grand Unified Theories (GUT's) with broken SUSY. We show that it is not possible to generate a realistic theory using our scheme. Strings exclude what is conceivable from the perspective of point field theories: getting a realistic GUT from a 6d theory with simple SUSY.
|
10 |
Topics in flux compactifications of type IIA superstring theoryIhl, Matthias, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.
|
Page generated in 0.1216 seconds