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D-branes, quivers, and ALE instantons
Effective field theories in type I and II superstring theories for D-branes located at points in the orbifold C^2/Z_n are supersymmetric gauge theories whose field content is conveniently summarized
A Black Hole Farey Tail
We derive an exact expression for the Fourier coefficients of elliptic genera of Calabi-Yau manifolds. When applied to k-fold symmetric products of K3 surfaces the expression is well-suited to
Elliptic Genera of Symmetric Products and Second Quantized Strings
Abstract: In this note we prove an identity that equates the elliptic genus partition function of a supersymmetric sigma model on the N-fold symmetric product of a manifold M to the partition
Integration over the u-plane in Donaldson theory
We analyze the u-plane contribution to Donaldson invariants of a fourmanifold X. For b2 (X) > 1, this contribution vanishes, but for b + 2 = 1, the Donaldson invariants must be written as the sum of
D-Brane Instantons and K-Theory Charges
We discuss some physical issues related to the K-theoretic classification of D-brane charges, putting an emphasis on the role of D-brane instantons. The relation to D-instantons provides a physical
Remarks on Tachyon Condensation in Superstring Field Theory
We generalize recent results on tachyon condensation in boundary string field theory to the superstring.
Some exact results on tachyon condensation in string field theory
The study of open string tachyon condensation in string field theory can be drastically simplified by making an appropriate choice of coordinates on the space of string fields. We show that a very
D-Particle Bound States and Generalized Instantons
Abstract:We compute the principal contribution to the index in the supersymmetric quantum mechanical systems which are obtained by reduction to 0 + 1 dimensions of , D= 4,6,10 super-Yang–Mills
A Derivation of K theory from M theory
We show how some aspects of the K-theory classification of RR fluxes follow from a careful analysis of the phase of the M-theory action. This is a shortened and simplified companion paper to ``E8
Counting BPS black holes in toroidal Type II string theory
We derive a $U$-duality invariant formula for the degeneracies of BPS multiplets in a D1-D5 system for toroidal compactification of the type II string. The elliptic genus for this system vanishes,