Cosmological Signature of Tachyon Condensation

TL;DR

This paper investigates how open string tachyon condensation, coupled with the dilaton in string field theory, can lead to cosmological oscillations matching observed quasar spectral data.

Contribution

It demonstrates the significant impact of dilaton coupling on tachyon dynamics, revealing cosmological-scale oscillations in the Hubble parameter.

Findings

Oscillation period estimated at 0.1-1 Gyr

Good agreement with observed quasar spectral oscillations

Dilaton influence is crucial for tachyon cosmology

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. Coupling of the open string tachyon and the dilaton is motivated by the open String Field Theory in a linear dilaton background and the flat space-time. We note that the dilaton gravity provides several restrictions on the tachyon condensation and show explicitly that the influence of the dilaton on the tachyon condensation is essential and provides 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) Gyr and note a good agreement of this period with the observed oscillations with a period (0.15-0.65) Gyr in a distribution of quasar spectra.