Dissertation/Thesis Abstract

Worldsheet aspects of heterotic string compactifications
by McOrist, Jock, Ph.D., The University of Chicago, 2009, 160; 3369454
Abstract (Summary)

This thesis is devoted to understanding α' corrections in a certain class of heterotic compactifications. These compactifications preserve [special characters omitted] = 1 supersymmetry in four dimensions, and have a worldsheet description with (0, 2) supersymmetry. Such compactifications are thought to be the easiest and most promising route to semi-realistic phenomenology, and yet little is understood about their worldsheet description.

We make some progress in this direction by understanding half-twisted (0, 2) superconformal field theories realized as infrared fixed point of linear sigma models. The particular (0, 2) models we study are constructed by deforming (2, 2) linear sigma models, and are stable against worldsheet instanton effects. At large volume, these compactifications are described by a six-dimensional geometry (a complete intersection Calabi-Yau in a projective toric variety) together with a holomorphic vector bundle constructed by deforming the tangent bundle. At low-energies the compactification is described by an E6 gauge theory, with an E8 hidden sector, matter multiplets in the 27 and 27 of E6 together with complex structure, Kähler and bundle moduli.

By studying the relevant quasi-topological sectors, and using a generalization of techniques familiar from (2, 2) theories, we compute some of the α' corrections to this field theoretic description. First, we elucidate the local parameter space of these (0, 2) models, and compute the dependence of genus zero correlators on these parameters. Second, we show that in these theories the correlators and parameter dependence split into A and B types in a fashion analogous to (2, 2) theories. We present techniques for computing un-normalized Yukawa couplings in general, and illustrate their usage in a variety of examples. At large volume, the Yukawa couplings reduce to the supergravity result together with a series of α' corrections. Our results are also relevant to the mathematics of (0, 2) mirror symmetry.

Indexing (document details)
Advisor: Sethi, Savdeep S.
Commitee: Martinec, Emil, Oreglia, Mark, Santra, Robin
School: The University of Chicago
Department: Physics
School Location: United States -- Illinois
Source: DAI-B 70/08, Dissertation Abstracts International
Subjects: Theoretical physics
Keywords: Mirror symmetry, String compactifications, String theory, Toric geometry
Publication Number: 3369454
ISBN: 978-1-109-31564-6
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