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 give a covariant realization of the doubled sigma-model formulation of duality-symmetric
string theory within the general framework of para-Hermitian geometry. We define a notion of …

A bstract We investigate geometric aspects of double field theory (DFT) and its formulation
as a doubled membrane sigma-model. Starting from the standard Courant algebroid over …

A bstract We extend the notion of Lie bialgebroids for more general bracket structures used
in string and M theories. We formalize the notions of calculus and dual calculi on algebroids …

Motivated from target space covariant formulations of topological sigma models and from a
graded-geometric approach to higher gauge theory, we study connections on Lie and …

The integration problem of a C-bracket and a Vaisman (metric, pre-DFT) algebroid that are
geometric structures of double field theory (DFT) is analyzed. We introduce a notion of a pre …

A bstract Starting from a higher Courant bracket associated to exceptional generalized
geometry, we provide a systematic derivation of all types of fluxes and their Bianchi identities …

We introduce T-duality invariant versions of D-branes in doubled geometry using a global
covariant framework based on para-Hermitian geometry and metric algebroids. We define D …

By doubling the target space of a canonical Courant algebroid and subsequently projecting
down to a specific subbundle, we identify the data of double field theory (DFT) and hence …

We introduce a technique to realize brane wrapping and double dimensional reduction in
the context of Alexandrov-Kontsevich-Schwarz-Zaboronsky (AKSZ) topological sigma …