Anisotropic homogeneous string cosmology with two-loop corrections

F. Naderi, A. Rezaei-Aghdam
2017 Nuclear Physics B  
The two-loop (order α') β-function equations, which are equivalent to the equations of motion of α'-corrected string effective action, are considered for anisotropic homogeneous space-times. These equations are solved for all Bianchi-type models in two schemes of effective action, namely R^2 and Gauss-Bonnet schemes with zero cosmological constant and then the metric, dilaton and B-field are found at α' perturbative corrections.
doi:10.1016/j.nuclphysb.2017.08.005 fatcat:ufdvzgmbhfgjxo6ivleplc6bvy