Nicholas P. Warner

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Quantum integrable models that possess N = 2 supersymmetry are investigated on the half-space. Conformal perturbation theory is used to identify some N = 2 supersymmetric boundary integrable models, and the effective boundary Landau-Ginzburg formulations are constructed. It is found that N = 2 supersymmetry largely determines the boundary action in terms of(More)
  • J A Minahan, D Nemeschansky, C Vafa, N P Warner
  • 1998
We study certain properties of six-dimensional tensionless E-strings (arising from zero size E 8 instantons). In particular we show that n E-strings form a bound string which carries an E 8 level n current algebra as well as a left-over conformal system with c = 12n − 4 − 248n n+30 , whose characters can be computed. Moreover we show that the characters of(More)
After the work of Seiberg and Witten, it has been seen that the dynamics of N=2 Yang-Mills theory is governed by a Riemann surface Σ. In particular, the integral of a special differential λ SW over (a subset of) the periods of Σ gives the mass formula for BPS-saturated states. We show that, for each simple group G, the Riemann surface is a spectral curve of(More)
We examine orbifolds of the IIB string via gauged supergravity. For the gravity duals of the A n−1 quiver gauge theories, we extract the massless degrees of freedom and assemble them into multiplets of N = 4 gauged supergravity in five dimensions. We examine the embedding of the gauge group into the isometry group of the scalar manifold, as well as the(More)
We show that almost all string theories, including the bosonic string, the superstring and W-string theories, possess a twisted N = 2 superconformal symmetry. This enables us to establish a connection between topological gravity and the field theoretical description of matter coupled to gravity. We also show how the BRST operators of the W n-string can be(More)
We use the effective action of the E n non-critical strings to study its BPS spectrum for 0 ≤ n ≤ 8. We show how to introduce mass parameters, or Wilson lines, into the effective action, and then perform the appropriate asymptotic expansions that yield the BPS spectrum. The result is the E n character expansion of the spectrum, and is equivalent to(More)