Cosmological ??-corrections from the functional renormalization group

A bstract We employ the techniques of Functional Renormalization Group in string theory, order to derive an effective mini-superspace action for cosmological backgrounds all orders scale ?? . To this end, T-duality plays a crucial role, classifying perturbative curvature corrections terms single function Hubble parameter. The resulting renormalization group equations admit exact, albeit non-analytic, solution any spacetime dimension D , which is however incompatible with Einstein gravity at low energies. Within E -expansion about = 2, we also find analytic exhibits non-Gaussian ultraviolet fixed point positive Newton coupling, as well acceptable low-energy limit. Yet, within polynomial truncations full theory space, no evidence analog 4. Finally, comment on potential implications our findings.