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Title: Duality cascade in brane inflation

Abstract

We show that brane inflation is very sensitive to tiny sharp features in extra dimensions, including those in the potential and in the warp factor. This can show up as observational signatures in the power spectrum and/or non-Gaussianities of the cosmic microwave background radiation (CMBR). One general example of such sharp features is a succession of small steps in a warped throat, caused by Seiberg duality cascade using gauge/gravity duality. We study the cosmological observational consequences of these steps in brane inflation. Since the steps come in a series, the prediction of other steps and their properties can be tested by future data and analysis. It is also possible that the steps are too close to be resolved in the power spectrum, in which case they may show up only in the non-Gaussianity of the CMB temperature fluctuations and/or EE polarization. We study two cases. In the slow-roll scenario, where steps appear in the inflaton potential, the sensitivity of brane inflation to the height and width of the steps is increased by several orders of magnitude compared to that in previously studied large field models. In the IR DBI scenario, where steps appear in the warp factor, we find thatmore » the glitches in the power spectrum caused by these sharp features are generally small or even unobservable, but associated distinctive non-Gaussianity can be large. Together with its large negative running of the power spectrum index, this scenario clearly illustrates how rich and different a brane inflationary scenario can be when compared to generic slow-roll inflation. Such distinctive stringy features may provide a powerful probe of superstring theory.« less

Authors:
 [1];  [2];  [3];
  1. Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States)
  2. Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)
  3. Newman Laboratory for Elementary Particle Physics, Cornell University, Ithaca, NY 14853 (United States)
Publication Date:
OSTI Identifier:
22137825
Resource Type:
Journal Article
Journal Name:
Journal of Cosmology and Astroparticle Physics
Additional Journal Information:
Journal Volume: 2008; Journal Issue: 03; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1475-7516
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DUALITY; GAUGE INVARIANCE; GRAVITATION; POTENTIALS; RELICT RADIATION; SUPERSTRING MODELS; SUPERSTRING THEORY; TEMPERATURE DEPENDENCE

Citation Formats

Bean, Rachel, Xingang, Chen, Hailu, Girma, Henry Tye, S-H, and Xu Jiajun, E-mail: rbean@astro.cornell.edu, E-mail: xgchen@mit.edu, E-mail: hailu@lepp.cornell.edu, E-mail: tye@lepp.cornell.edu, E-mail: jx33@cornell.edu. Duality cascade in brane inflation. United States: N. p., 2008. Web. doi:10.1088/1475-7516/2008/03/026.
Bean, Rachel, Xingang, Chen, Hailu, Girma, Henry Tye, S-H, & Xu Jiajun, E-mail: rbean@astro.cornell.edu, E-mail: xgchen@mit.edu, E-mail: hailu@lepp.cornell.edu, E-mail: tye@lepp.cornell.edu, E-mail: jx33@cornell.edu. Duality cascade in brane inflation. United States. doi:10.1088/1475-7516/2008/03/026.
Bean, Rachel, Xingang, Chen, Hailu, Girma, Henry Tye, S-H, and Xu Jiajun, E-mail: rbean@astro.cornell.edu, E-mail: xgchen@mit.edu, E-mail: hailu@lepp.cornell.edu, E-mail: tye@lepp.cornell.edu, E-mail: jx33@cornell.edu. Sat . "Duality cascade in brane inflation". United States. doi:10.1088/1475-7516/2008/03/026.
@article{osti_22137825,
title = {Duality cascade in brane inflation},
author = {Bean, Rachel and Xingang, Chen and Hailu, Girma and Henry Tye, S-H and Xu Jiajun, E-mail: rbean@astro.cornell.edu, E-mail: xgchen@mit.edu, E-mail: hailu@lepp.cornell.edu, E-mail: tye@lepp.cornell.edu, E-mail: jx33@cornell.edu},
abstractNote = {We show that brane inflation is very sensitive to tiny sharp features in extra dimensions, including those in the potential and in the warp factor. This can show up as observational signatures in the power spectrum and/or non-Gaussianities of the cosmic microwave background radiation (CMBR). One general example of such sharp features is a succession of small steps in a warped throat, caused by Seiberg duality cascade using gauge/gravity duality. We study the cosmological observational consequences of these steps in brane inflation. Since the steps come in a series, the prediction of other steps and their properties can be tested by future data and analysis. It is also possible that the steps are too close to be resolved in the power spectrum, in which case they may show up only in the non-Gaussianity of the CMB temperature fluctuations and/or EE polarization. We study two cases. In the slow-roll scenario, where steps appear in the inflaton potential, the sensitivity of brane inflation to the height and width of the steps is increased by several orders of magnitude compared to that in previously studied large field models. In the IR DBI scenario, where steps appear in the warp factor, we find that the glitches in the power spectrum caused by these sharp features are generally small or even unobservable, but associated distinctive non-Gaussianity can be large. Together with its large negative running of the power spectrum index, this scenario clearly illustrates how rich and different a brane inflationary scenario can be when compared to generic slow-roll inflation. Such distinctive stringy features may provide a powerful probe of superstring theory.},
doi = {10.1088/1475-7516/2008/03/026},
journal = {Journal of Cosmology and Astroparticle Physics},
issn = {1475-7516},
number = 03,
volume = 2008,
place = {United States},
year = {2008},
month = {3}
}