We present a brief overview of attempts to construct de Sitter vacua in string theory and
explain how the results of this 20-year endeavor could point to the fact that string theory …

We review various aspects of de Sitter spacetime in string theory: its status as an Effective
Field Theory spacetime solution, its relation to the vacuum energy problem in string theory …

We present a formulation of Double Field Theory with a Drinfeld double as extended
spacetime. It makes Poisson-Lie T-duality (including abelian and non-abelian T-duality as …

A bstract The worldsheet theories that describe Poisson-Lie T-dualisable σ-models on group
manifolds as well as integrable η, λ and β-deformations provide examples of ℰ-models …

A bstract We construct an O (d, d) invariant universal formulation of the first-order α′-
corrections of the string effective actions involving the dilaton, metric and two-form fields …

A bstract In this work the exceptional field theory formulation of supergravity with SL (5)
gauge group is considered. This group appears as a U-duality group of D= 7 maximal …

String theory has-duality symmetry when the target space has Abelian isometries. A
generalization of-duality, where the isometry group is non-Abelian, is known as non-Abelian …

A bstract Generalized dualities had an intriguing incursion into Double Field Theory (DFT) in
terms of local O (d, d) transformations. We review this idea and use the higher derivative …

A bstract The α′-deformed frame-like Double Field Theory (DFT) is a T-duality and gauge
invariant extension of DFT in which generalized Green-Schwarz transformations provide a …

A family of algebras that extends the Lie algebra of the Drinfel'd double is proposed. This
allows us to systematically construct the generalized frame fields which realize the proposed …