Non-local SFT Tachyon and Cosmology

TL;DR

This paper explores non-local string field theory and p-adic tachyons in cosmology, analyzing late-time dynamics and oscillatory behaviors of the universe's expansion influenced by tachyon fields.

Contribution

It provides a detailed analysis of the late-time behavior of tachyon fields in non-local string theory cosmology, including oscillations around the phantom divide.

Findings

Late-time tachyon dynamics lead to trivial cosmology around the non-perturbative vacuum.

Explicit solutions for tachyon and scale factor behavior with cosmological constant or perfect fluid.

Evidence of possible oscillations of the effective state parameter around the phantom divide.

Abstract

Cosmological scenarios built upon the generalized non-local String Field Theory and $p$-adic tachyons are examined. A general kinetic operator involving an infinite number of derivatives is studied as well as arbitrary parameter $p$. The late time dynamics of just the tachyon around the non-perturbative vacuum is shown to leave the cosmology trivial. A late time behavior of the tachyon and the scale factor of the FRW metric in the presence of the cosmological constant or a perfect fluid with $w>-1$ is constructed explicitly and a possibility of non-vanishing oscillations of the total effective state parameter around the phantom divide is proven.