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We complete the computation of viscous transport coefficients in the near horizon geometries that arise from a stack of black Dp-branes for p = 2, ..., 6 in the decoupling limit. The main new result is the obtention of the bulk viscosity which, for all p, is found to be related to the speed of sound by the simple relation ζ/η = −2(v 2 s − 1 p). For(More)
Let M(A) denote the comparison matrix of a square H-matrix A, that is, M(A) is an M-matrix. H-matrices such that their comparison matrices are nonsingular are well studied in the literature. In this paper, we study characterizations of H-matrices with either singular or nonsingular comparison matrices. The spectral radius of the Jacobi matrix of M(A) and(More)
Following the nonperturbative prescription for the jet quenching parameter recently proposed by Liu, Rajagopal and Wiedemann, we compute the first correction in the inverse 't Hooft coupling corresponding to string α ′ corrections in the dual background. We also consider the introduction of a chemical potential for the U(1) 3 gauged R-symmetry. While the(More)
We study N = 2 super Yang-Mills theory with gauge group SU(N) from the point of view of the Whitham hierarchy. We develop a new recursive method to compute the whole instanton expansion of the prepotential using the theta function associated to the root lattice of the group. Explicit results for the one and two-instanton corrections in SU(N) are presented.(More)
The KP hierarchy is hamiltonian relative to a one-parameter family of Poisson structures obtained from a generalized Adler map in the space of formal pseudodifferential symbols with noninteger powers. The resulting W-algebra is a one-parameter deformation of W KP admitting a central extension for generic values of the parameter, reducing naturally to W n(More)
We embed the Seiberg–Witten solution for the low energy dynamics of N = 2 super Yang–Mills theory with an even number of massive hypermultiplets into the Whitham hierarchy. Expressions for the first and second derivatives of the prepotential in terms of the Riemann theta function are provided which extend previous results by Gorsky, Marshakov, Mironov and(More)
We compute instanton corrections to the low energy effective prepotential of N = 2 supersymmetric theories in a variety of cases, including all classical gauge groups and even number of fundamental matter hypermultiplets. To this end, we take profit of a set of first-and second-order equations for the logarithmic derivatives of the prepotential with respect(More)