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Abstract
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We present noncritical Bianchi type I string cosmology solutions in the presence of central charge deficit
term Λ. The leading-order string frame curvature appears to be in the high curvature limit Rα0 ≳ 1, which
underlines the necessity of including higher-order α0 corrections. We give new solutions of two-loop (firstorder
α0) β-function equations of the σ model with nonzero Λ and the dilaton field in both cases of the
absence and presence of a spatially homogeneous H field (H ¼ dB). Also, the evolution of solutions is
studied in the Einstein frame, in which the string effective action can transform to Gauss-Bonnet gravity
model coupled to a dilaton field with potential. We study explicit examples in first-order α0 with chosen
values of appeared constants in the solutions and discuss the cosmological implications.
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