I elaborate on a link between the string–scale breaking of supersymmetry that occurs in a class of superstring models and the onset of inflation. The link rests on spatially flat cosmologies supported by a scalar field driven by an exponential potential. If, as in String Theory, this potential is steep enough, under some assumptions that are spelled out in the text the scalar can only climb up as it emerges from an initial singularity. In the presence of another mild exponential, slow–roll inflation is thus injected during the ensuing descent and definite imprints are left in the CMB power spectrum: the quadrupole is systematically reduced and, depending on the choice of two parameters, an oscillatory behavior can also emerge for low multipoles l <50, in qualitative agreement with WMAP9 and PLANCK data. The experimentally favored value of the spectral index, ns≈0.96, points to a potentially important role for the NS fivebrane, which is unstable in this class of models, in the Early Universe.

Brane SUSY Breaking and Inflation: Implications for Scalar Fields and CMB Distorsion

SAGNOTTI, AUGUSTO
2013

Abstract

I elaborate on a link between the string–scale breaking of supersymmetry that occurs in a class of superstring models and the onset of inflation. The link rests on spatially flat cosmologies supported by a scalar field driven by an exponential potential. If, as in String Theory, this potential is steep enough, under some assumptions that are spelled out in the text the scalar can only climb up as it emerges from an initial singularity. In the presence of another mild exponential, slow–roll inflation is thus injected during the ensuing descent and definite imprints are left in the CMB power spectrum: the quadrupole is systematically reduced and, depending on the choice of two parameters, an oscillatory behavior can also emerge for low multipoles l <50, in qualitative agreement with WMAP9 and PLANCK data. The experimentally favored value of the spectral index, ns≈0.96, points to a potentially important role for the NS fivebrane, which is unstable in this class of models, in the Early Universe.
2013
Moriond Meeting on `Electroweak Interactions and Unified Theories' & SQS 2013, Dubna, Russia, August 2013
Dubna
Les Arcs, France, 10-17 Jan 1989, Dubna, August 2013
Moriond 2013: Electroweak Interactions and Unified Theories & Dubna SQS 2013
Moriond & Dubna
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11384/4820
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