riassunto2

SQG1 - Strings/Brane Motivated Gravity

Speaker

Koshelev, Alexey

Talk Title

Rolling tachyon, Non-local cosmology and Dark Energy

Abstract

We consider the dynamics of the open string tachyon condensation in a framework of the cubic fermionic String Field Theory including a non-minimal coupling with closed string massless modes, the graviton and the dilaton. We show explicitly that the influence of the dilaton on the tachyon condensation is essential providing a significant effect: oscillations of the Hubble parameter and the state parameter become of a cosmological scale. We give an estimation for the period of these oscillations (0.1-1.0) Gyr and note a good agreement with the observed oscillations with a period (0.15-0.65) Gyr in a distribution of quasar spectra. Cosmological perturbations are analyzed and evolution of perturbations is studied. Several novel compared to canonical local scalar field cosmologies effects are stressed.

Talk view

sqg1_koshelev.pdf

 

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