“Brane Supersymmetry Breaking” is a peculiar string–scale mechanism that can unpair Bose and Fermi excitations in orientifold models. It results from the simultaneous presence, in the vacuum, of collections of D-branes and orientifolds that are not mutually BPS, and is closely tied to the scale of string excitations. It also leaves behind, for a mixing of dilaton and internal breathing mode, an exponential potential that is just too steep for a scalar to emerge from the initial singularity while descending it. As a result, in this class of models the scalar can generically bounce off the exponential wall, and this dynamics brings along, in the power spectrum, an infrared depression typically followed by a pre–inflationary peak. We elaborate on a possible link between this type of bounce and the low–ℓ end of the CMB angular power spectrum. For the first 32 multipoles, one can reach a 50% reduction in χ2 with respect to the standard CDM setting.

String Theory clues for the low-ℓ CMB ?

SAGNOTTI, AUGUSTO;
2014

Abstract

“Brane Supersymmetry Breaking” is a peculiar string–scale mechanism that can unpair Bose and Fermi excitations in orientifold models. It results from the simultaneous presence, in the vacuum, of collections of D-branes and orientifolds that are not mutually BPS, and is closely tied to the scale of string excitations. It also leaves behind, for a mixing of dilaton and internal breathing mode, an exponential potential that is just too steep for a scalar to emerge from the initial singularity while descending it. As a result, in this class of models the scalar can generically bounce off the exponential wall, and this dynamics brings along, in the power spectrum, an infrared depression typically followed by a pre–inflationary peak. We elaborate on a possible link between this type of bounce and the low–ℓ end of the CMB angular power spectrum. For the first 32 multipoles, one can reach a 50% reduction in χ2 with respect to the standard CDM setting.
International Conference on New Frontiers in Physics
Proceedings to the International Conference ICNFP 2014, to appear
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11384/55933
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? 9
social impact