skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Cosmological Aspects of String Compactifications

Abstract

The organization of this work is as follows. In Chapters 2, 3, and 4 they discuss the dynamics of unfixed moduli in quantum field theory and in string theory, with emphasis on applications to cosmological model-building. Moduli-stabilizing effects are not included, because the goal is to understand the evolution of moduli whose potentials remain approximately flat. In Chapter 5 they develop a technique for stabilizing moduli in the heterotic string, and they construct the first stabilized, weakly-coupled heterotic vacua. In Chapter 6 they utilize advances in the stabilization of type IIB compactifications to build the first models of inflation in stabilized string vacua. Finally, in Chapter 7 they examine the effects of volume-stabilization on the inflaton mass in closely-related scenarios of string inflation.

Authors:
;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
877223
Report Number(s):
SLAC-R-750
TRN: US200702%%241
DOE Contract Number:
AC02-76SF00515
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; QUANTUM FIELD THEORY; STABILIZATION; ASTROPHYSICS; Astrophysics,GRQC, HEPTH

Citation Formats

McAllister, Liam Patrick, and /Stanford U., Phys. Dept. /SLAC. Cosmological Aspects of String Compactifications. United States: N. p., 2006. Web. doi:10.2172/877223.
McAllister, Liam Patrick, & /Stanford U., Phys. Dept. /SLAC. Cosmological Aspects of String Compactifications. United States. doi:10.2172/877223.
McAllister, Liam Patrick, and /Stanford U., Phys. Dept. /SLAC. Fri . "Cosmological Aspects of String Compactifications". United States. doi:10.2172/877223. https://www.osti.gov/servlets/purl/877223.
@article{osti_877223,
title = {Cosmological Aspects of String Compactifications},
author = {McAllister, Liam Patrick and /Stanford U., Phys. Dept. /SLAC},
abstractNote = {The organization of this work is as follows. In Chapters 2, 3, and 4 they discuss the dynamics of unfixed moduli in quantum field theory and in string theory, with emphasis on applications to cosmological model-building. Moduli-stabilizing effects are not included, because the goal is to understand the evolution of moduli whose potentials remain approximately flat. In Chapter 5 they develop a technique for stabilizing moduli in the heterotic string, and they construct the first stabilized, weakly-coupled heterotic vacua. In Chapter 6 they utilize advances in the stabilization of type IIB compactifications to build the first models of inflation in stabilized string vacua. Finally, in Chapter 7 they examine the effects of volume-stabilization on the inflaton mass in closely-related scenarios of string inflation.},
doi = {10.2172/877223},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Mar 10 00:00:00 EST 2006},
month = {Fri Mar 10 00:00:00 EST 2006}
}

Technical Report:

Save / Share:
  • Warped compactifications with significant warping provide one of the few known mechanisms for naturally generating large hierarchies of physical scales. We demonstrate that this mechanism is realizable in string theory, and give examples involving orientifold compactifications of IIB string theory and F-theory compactifications on Calabi-Yau four-folds. In each case, the hierarchy of scales is fixed by a choice of RR and NS fluxes in the compact manifold. Our solutions involve compactifications of the Klebanov-Strassler gravity dual to a confining N = 1 supersymmetric gauge theory, and the hierarchy reflects the small scale of chiral symmetry breaking in the dual gaugemore » theory.« less
  • We study the cosmology induced on a brane probing a warped throat region in a Calabi-Yau compactification of type IIB string theory. For the case of a BPS D3-brane probing the Klebanov-Strassler warped deformed conifold, the cosmology described by a suitable brane observer is a bouncing, spatially flat Friedmann-Robertson-Walker universe with time-varying Newton's constant, which passes smoothly from a contracting to an expanding phase. In the Klebanov-Tseytlin approximation to the Klebanov-Strassler solution the cosmology would end with a big crunch singularity. In this sense, the warped deformed conifold provides a string theory resolution of a spacelike singularity in the branemore » cosmology. The four-dimensional effective action appropriate for a brane observer is a simple scalar-tensor theory of gravity. In this description of the physics, a bounce is possible because the relevant energy-momentum tensor can classically violate the null energy condition.« less
  • We describe a new class of supersymmetric string compactifications to 4d Minkowski space. These solutions involve type II strings propagating on (orientifolds of) non Calabi-Yau spaces in the presence of background NS and RR fluxes. The simplest examples have descriptions as cosets, generalizing the three-dimensional nilmanifold. They can also be thought of as twisted tori. We derive a formula for the (super)potential governing the light fields, which is generated by the fluxes and certain ''twists'' in the geometry. Detailed consideration of an example also gives strong evidence that in some cases, these exotic geometries are related by smooth transitions tomore » standard Calabi-Yau or G2 compactifications of M-theory.« less
  • In string compactification on a manifold X, in addition to the string scale and the normal scales of low-energy particle physics, there is a Kaluza-Klein scale 1/R associated with the size of X. We present an argument that generic string models with low-energy supersymmetry have, after moduli stabilization, bulk fields with masses which are parametrically lighter than 1/R. We discuss the implications of these light states for anomaly mediation and gaugino mediation scenarios.
  • We provide a qualitative review of flux compactifications of string theory, focusing on broad physical implications and statistical methods of analysis.