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

Title: How delicate is brane-antibrane inflation?

Abstract

We systematically explore the parameter space of the state-of-the-art brane-antibrane inflation model (Baumann et al., arXiv:0706.0360, arXiv:0705.3837) which is one of the most rigorously derived from string theory, applying the cosmic background explorer normalization and constraint on the spectral index. We improve on previous treatments of uplifting by antibranes and show that the contributions from noninflationary throats play an important role in achieving a flat inflationary potential. To quantify the degree of fine-tuning needed by the model, we define an effective volume in the part of parameter space which is consistent with experimental constraints, and using Monte Carlo methods to search for a set of optimal parameters, we show that the degree of fine-tuning is alleviated by 8 orders of magnitude relative to a fiducial point which has previously been considered. In fact, close to the optimal parameter values, fine-tuning is no longer needed for any of the parameters. We show that in this natural region of the parameter space, larger values of n{sub s} close to 0.99 (still within 2{sigma} of the WMAP5 central value) are favored, giving a new aspect of testability to the model.

Authors:
;  [1]
  1. Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, H3A 2T8 (Canada)
Publication Date:
OSTI Identifier:
21308294
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 79; Journal Issue: 8; Other Information: DOI: 10.1103/PhysRevD.79.083537; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BRANES; MONTE CARLO METHOD; POTENTIALS; SIMULATION; SPACE; STRING MODELS; STRING THEORY

Citation Formats

Hoi, Loison, and Cline, James M. How delicate is brane-antibrane inflation?. United States: N. p., 2009. Web. doi:10.1103/PHYSREVD.79.083537.
Hoi, Loison, & Cline, James M. How delicate is brane-antibrane inflation?. United States. https://doi.org/10.1103/PHYSREVD.79.083537
Hoi, Loison, and Cline, James M. Wed . "How delicate is brane-antibrane inflation?". United States. https://doi.org/10.1103/PHYSREVD.79.083537.
@article{osti_21308294,
title = {How delicate is brane-antibrane inflation?},
author = {Hoi, Loison and Cline, James M},
abstractNote = {We systematically explore the parameter space of the state-of-the-art brane-antibrane inflation model (Baumann et al., arXiv:0706.0360, arXiv:0705.3837) which is one of the most rigorously derived from string theory, applying the cosmic background explorer normalization and constraint on the spectral index. We improve on previous treatments of uplifting by antibranes and show that the contributions from noninflationary throats play an important role in achieving a flat inflationary potential. To quantify the degree of fine-tuning needed by the model, we define an effective volume in the part of parameter space which is consistent with experimental constraints, and using Monte Carlo methods to search for a set of optimal parameters, we show that the degree of fine-tuning is alleviated by 8 orders of magnitude relative to a fiducial point which has previously been considered. In fact, close to the optimal parameter values, fine-tuning is no longer needed for any of the parameters. We show that in this natural region of the parameter space, larger values of n{sub s} close to 0.99 (still within 2{sigma} of the WMAP5 central value) are favored, giving a new aspect of testability to the model.},
doi = {10.1103/PHYSREVD.79.083537},
url = {https://www.osti.gov/biblio/21308294}, journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 8,
volume = 79,
place = {United States},
year = {2009},
month = {4}
}