In this review, a number of approaches to superstring cosmology which make use of key
features which distinguish string theory from point particle theories are discussed, with …

While the classification of α′ corrections of string inspired effective theories remains an
unsolved problem, we show how to classify duality invariant α′ corrections for purely time …

A bstract 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 …

A bstract In a recent paper it was shown that fundamental strings are null waves in Double
Field Theory. Similarly, membranes are waves in exceptional extended geometry. Here the …

We perform a thorough analysis of de Sitter solutions in O (d, d) invariant cosmologies.
Starting with a homogeneous and isotropic framework we examine conditions for the …

A bstract The cosmology of the fully α′-corrected duality-invariant action for the Neveu-
Schwarz sector of string theory is revisited, with special emphasis on its coupling to matter …

We investigate the cosmological solutions coming from the double field theory equations of
motion after coupling a matter source to them. Assuming constant dilaton and imposing the …

The phase space formulation of double field theory (DFT) indicates that statistical matter can
be included in terms of (T-) duality multiplets. We propose the inclusion of a perfect fluid in …

T-dual cosmological solutions in double field theory. II. Page 1 T-dual cosmological solutions in
double field theory. II. Heliudson Bernardo,1,* Robert Brandenberger,2,† and Guilherme …

In string theory the closed-string massless NS-NS sector forms a multiplet of O (D, D) O (D,
D) symmetry. This suggests a specific modification to General Relativity in which the entire …