General string cosmologies at order <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>α</mml:mi><mml:mrow><mml:mo>′</mml:mo><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:math>

Abstract

We compute the cosmological reduction of general string theories, including bosonic, heterotic, and type II string theory to order ${\ensuremath{\alpha}}^{\ensuremath{'}3}$, i.e., with up to eight derivatives. To this end, we refine recently introduced methods that allow one to bring the reduced theory in one dimension to a canonical form with only first-order time derivatives. The resulting theories are compatible with a continuous $O(d,d,\mathbb{R})$ invariance, which in turn fixes the B-field couplings.

Topics & Concepts