5D Black Rings and 4D Black Holes

It has recently been shown that the M theory lift of a IIA 4D BPS Calabi-Yau black hole is a 5D BPS black hole spinning at the center of a Taub-NUT-flux geometries, and a certain linear relation between 4D and 5D BPS partition functions was accordingly proposed. In the present work we fortify and enrich this proposal by showing that the M-theory lift of the general 4D multi-black hole geometry are 5D black rings in a Taub-NUT-flux geometry.Comment: 8 pages; version 2, with additional references and explanation

New Attractors and Area Codes

In this note we give multiple examples of the recently proposed New Attractors describing supersymmetric flux vacua and non-supersymmetric extremal black holes in IIB string theory. Examples of non-supersymmetric extremal black hole attractors arise on a hypersurface in $WP^{4}_{1,1,1,1,2}$. For flux vacua on the orientifold of the same hypersurface existence of multiple basins of attraction is established. It is explained that certain fluxes may give rise to multiple supersymmetric flux vacua in a finite region on moduli space, say at the Landau-Ginzburg point and close to conifold point. This suggests the existence of multiple basins for flux vacua and domain walls in the landscape for a fixed flux and at interior points in moduli space.Comment: 16 pages, harvmac. v2: acknowledgement update

The Non-BPS Black Hole Attractor Equation

We study the attractor mechanism for extremal non-BPS black holes with an infinite throat near horizon geometry, developing, as we do so, a physical argument as to why such a mechanism does not exist in non-extremal cases. We present a detailed derivation of the non-supersymmetric attractor equation. This equation defines the stabilization of moduli near the black hole horizon: the fixed moduli take values specified by electric and magnetic charges corresponding to the fluxes in a Calabi Yau compactification of string theory. They also define the so-called double-extremal solutions. In some examples, studied previously by Tripathy and Trivedi, we solve the equation and show that the moduli are fixed at values which may also be derived from the critical points of the black hole potential.Comment: 32 Pages, 2 Figures, LaTeX; v2: typos corrected, references adde

Intersections forms and the geometry of lattice Chern-Simons theory

We show that it is possible to formulate Abelian Chern-Simons theory on a lattice as a topological field theory. We discuss the relationship between gauge invariance of the Chern-Simons lattice action and the topological interpretation of the canonical structure. We show that these theories are exactly solvable and have the same degrees of freedom as the analogous continuum theories.Comment: 14 page

Probing the dark matter profile of hot clusters and the M-T relation with XMM-Newton

We present results based on XMM-Newton observations of a small sample of hot galaxy clusters. Making a full use of XMM-Newton's spectro-imaging capabilities, we have extracted the radial temperature profile and gas density profile, and with this information, calculated the total mass profile of each cluster (under the assumption of hydrostatic equilibrium and spherical symmetry). Comparing the individual scaled total mass profiles, we have probed the Universality of rich cluster mass profiles over a wide range of radii (from 0.01 to 0.7 the virial radius). We have also tested the shape of cluster mass profiles by comparing with the predicted profiles from numerical simulations of hierarchical structure formation. We also derived the local mass-temperature (M-T) scaling relation over a range of temperature going from 4 to 9 keV, that we compare with theoretical predictions.Comment: 7 pages, 2 figures, Advances in Space Research in press (proceedings of the COSPAR 2004 Assembly, Paris

High-Energy Symmetry of Bosonic Open String Theory in the Light-like Linear Dilaton Background

High-energy limits of fixed-angle tree-level stringy scattering amplitudes in the light-like linear dilaton background are calculated. Treating the time component of the gradient of light-like dilaton field (V_0) as a moduli parameter, we show that: (1) there exists a new fixed-point (V_0/E \to \infty) in the moduli space of the bosonic open string theory, where a new high-energy symmetry among scattering amplitudes can be identified, (2) this new symmetry can be interpreted as a deformation of the flat-space high-energy symmetry, as proposed by D. Gross. Hence, our results give a concrete illustration about the relation between high-energy stringy symmetry and the background independent formulation of string theory.Comment: 42pages, 3figures, 5tables, typos corrected, commments and reference added

Extended Holomorphic Anomaly in Gauge Theory

The partition function of an N=2 gauge theory in the Omega-background satisfies, for generic value of the parameter beta=-eps_1/eps_2, the, in general extended, but otherwise beta-independent, holomorphic anomaly equation of special geometry. Modularity together with the (beta-dependent) gap structure at the various singular loci in the moduli space completely fixes the holomorphic ambiguity, also when the extension is non-trivial. In some cases, the theory at the orbifold radius, corresponding to beta=2, can be identified with an "orientifold" of the theory at beta=1. The various connections give hints for embedding the structure into the topological string.Comment: 25 page

Branes, Rings and Matrix Models in Minimal (Super)string Theory

We study both bosonic and supersymmetric (p,q) minimal models coupled to Liouville theory using the ground ring and the various branes of the theory. From the FZZT brane partition function, there emerges a unified, geometric description of all these theories in terms of an auxiliary Riemann surface M_{p,q} and the corresponding matrix model. In terms of this geometric description, both the FZZT and ZZ branes correspond to line integrals of a certain one-form on M_{p,q}. Moreover, we argue that there are a finite number of distinct (m,n) ZZ branes, and we show that these ZZ branes are located at the singularities of M_{p,q}. Finally, we discuss the possibility that the bosonic and supersymmetric theories with (p,q) odd and relatively prime are identical, as is suggested by the unified treatment of these models.Comment: 72 pages, 3 figures, improved treatment of FZZT and ZZ branes, minor change