We review recent developments in duality symmetric string theory. We begin with the world-
sheet doubled formalism which describes strings in an extended spacetime with extra …

We investigate a simple class of type-II string compactifications which incorporate
nongeometric``fluxes''in addition to``geometric flux''and the usual H-field and RR fluxes …

In string theory, the concept of T-duality between two principal Tn-bundles E and Ê over the
same base space B, together with cohomology classes h∈ H3 (E, ℤ) and ĥ∈ H3 (Ê, ℤ), has …

The gauged sigma-model argument that string backgrounds related by T-duality give
equivalent quantum theories is revisited, taking careful account of global considerations …

The four-dimensional N= 1 supergravity theories arising in compactifications of type IIA and
type IIB on generalized orientifold backgrounds with background fluxes are discussed. The …

These notes present a pedagogical review of nongeometric flux compactifications. We begin
by reviewing well-known geometric flux compactifications in Type II string theory, and argue …

A bstract We consider the geometric and non-geometric faces of closed string vacua arising
by T-duality from principal torus bundles with constant H-flux and pay attention to their …

Type IIA toroidal orientifolds offer a promising toolkit for model builders, especially when one
includes not only the usual fluxes from NS-NS and RR field strengths, but also fluxes that are …

We develop some of the ingredients needed for string theory on noncommutative
spacetimes, proposing an axiomatic formulation of T-duality as well as establishing a very …

A bstract We propose a non-associative phase space algebra for M-theory backgrounds with
locally non-geometric fluxes based on the non-associative algebra of octonions. Our …