We study 0-branes in type IIA on T 2 with a background B-field turned on. This enables us to find the matrix model for M-theory on T 2 with a background 3-form potential along the torus and theâ€¦ (More)

When a D-brane wraps around a cycle of a curved manifold, the twisting of its normal bundle can induce chiral asymmetry in its world-volume theory. We obtain the general form of the resultingâ€¦ (More)

We provide a complete solution of closed strings propagating in NappiWitten space. Based on the analysis of geodesics we construct the coherent wavefunctions which approximate as closely as possibleâ€¦ (More)

We show that the moduli space of the (2, 0) and little-string theories compactified on T 3 with R-symmetry twists is equal to the moduli space of U(1) instantons on a noncommutative T . The moduliâ€¦ (More)

We study the compactification of the (2, 0) and type-II little-string theories on S, T 2 and T 3 with an R-symmetry twist that preserves half the supersymmetry. We argue that it produces the sameâ€¦ (More)

In a given 4d spacetime bakcground, one can often construct not one but a family of distinct N = 2 string theories. This is due to the multiple ways an N = 2 superconformal algebra can be embedded inâ€¦ (More)

We study the two-point correlators of the currents of the E8 global symmetry in the N = (1, 0) superconformal six-dimensional theory as well as in the 4D superconformal theories upon toroidalâ€¦ (More)

Stabilizing all of the modulus fields coming from compactifications of string theory on internal manifolds is one of the outstanding challenges for string cosmology. Here, in a simple example ofâ€¦ (More)

Scalar fields appear in many theories beyond the Standard Model of particle physics. In the early universe, they are exposed to extreme conditions, including high temperature and rapid cosmicâ€¦ (More)

WZW models are abstract conformal field theories with an infinite dimensional symmetry which accounts for their integrability, and at the same time they have a sigma model description of closedâ€¦ (More)