O(d, d) covariant string cosmology to all orders in α′

Abstract

Recently, all duality invariant α -corrections to the massless NS-NS sector of string theory on time-dependent backgrounds were classified and the form of their contribution to the action were calculated. In this paper we introduce matter sources in the resulting equations of motion in an O(d, d) covariant way. We show that either starting with the corrected equations and sourcing them with matter or considering corrections to the matter sourced lowest order equations give the same set of equations that defines string cosmology to all orders in α . We also discuss perturbative and non-perturbative de Sitter solutions including matter, and explicitly show that de Sitter solutions are allowed non-perturbatively. *

α′-cosmology: solutions and stability analysis

“…Recently, assuming this to be true to all orders, the form of the α -corrections were found, allowing a suitable classification of these corrections [30]. 1 A natural extension of their results involved the inclusion of a matter sector [33], which finally allows us to consider realistic cosmological solutions.…”

“…Our goal in this paper is to briefly review O(d, d) String Cosmology including αcorrections [30,33], then to present and discuss some of its cosmological solutions and finally to consider their stability. This will open precedent to consider realistic cosmological scenarios in future works and to investigate the feasibility of the models discussed above and beyond.…”

“…For a cosmological background, we consider the fields given as G 00 = −n 2 (t), G 0i = 0, G ij = g ij (t), B 00 = 0, B 0i = 0, B ij = b ij (t) and φ = φ(t). Then, the action for these fields coupled to matter including α -corrections to all orders, which are constrained by O(d, d) symmetry, has been shown to have the form [33]…”

“…The solutions to the α -Cosmological equations (2.10) started to be considered in [33]. Before we consider their stability, we will briefly review them and also introduce some new solutions that provide appealing cosmological scenarios.…”

Generalized dualities and higher derivatives

“…It would be interesting to apply our result to specific examples. Higher-derivative corrections to Abelian T-duality have been applied in different contexts, such as corrections to entropy and black-hole solutions [89][90][91][92][93] and cosmological backgrounds [94][95][96]. Higher-derivative corrections to Yang-Baxter deformations were recently considered in [45].…”