SÉMINAIRE DU GRECO
"Theoretical constraints on brane inflation and cosmic superstring radiation" |
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R. Gwyn |
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Cosmic superstrings can arise naturally at the end of brane inflation in string theory. By studying the types of strings produced and the radiation they emit, we might hope to add to the catalogue of observational signatures from different inflation models, and to point out possible indirect evidence of string theory via cosmic superstrings. We analyze theoretical constraints on the consistency of brane inflation leading to cosmic superstring formation and on the subsequent radiation of these cosmic superstrings. We first investigate the implications of recently elucidated supergravity constraints on models of brane inflation, showing that both D3/D7 and D3/anti-D3 brane inflation are subject to non-trivial constraints. It can be argued that both models satisfy those constraints, but for the case of D3/D7 there may be important consequences for the inflationary mechanism. We then analyze the strong theoretical constraints on the types of allowed radiation by cosmic superstrings, should they be formed, such constraints do not apply to their field theoretical analogues. We argue that in a warped background where one might expect axionic radiation to be enhanced relative to gravitational radiation, neither F-strings nor D-strings can emit axionic radiation, while FD-strings cannot give rise to Neveu-Schwarz--Neveu-Schwarz particle emission, and their Ramond-Ramond particle emission is not well-defined. |
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lundi 31 octobre 2011 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris |
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