English

Non-critical anisotropic Bianchi type $I$ string cosmology with $\alpha'$-corrections

High Energy Physics - Theory 2018-07-10 v3 General Relativity and Quantum Cosmology

Abstract

We present non-critical Bianchi type II string cosmology solutions in the presence of central charge deficit term Λ\Lambda. The leading order string frame curvature appears to be in the high curvature limit Rα1R\alpha'\gtrsim1, which underlines the necessity of including higher order α\alpha'-corrections. We give new solutions of two-loop (order α\alpha') β\beta-function equations of σ\sigma-model with non-zero Λ\Lambda and dilaton field in both cases of absence and presence of spatially homogeneous HH-field (H=dBH=dB). Also, the evolution of solutions is studied in the Einstein frame, where the string effective action can transform to Gauss-Bonnet gravity model coupled to the dilaton field with potential. We study explicit examples in order α\alpha' with chosen values of appeared constants in the solutions and discuss the cosmological implications.

Keywords

Cite

@article{arxiv.1712.03581,
  title  = {Non-critical anisotropic Bianchi type $I$ string cosmology with $\alpha'$-corrections},
  author = {F. Naderi and A. Rezaei-Aghdam and F. Darabi},
  journal= {arXiv preprint arXiv:1712.03581},
  year   = {2018}
}
R2 v1 2026-06-22T23:13:38.291Z