Metrics Admitting Killing Spinors In Five Dimensions

BPS black hole configurations which break half of supersymmetry in the theory of N=2, d=5 supergravity coupled to an arbitrary number of abelian vector multiplets are discussed. A general class of solutions comprising all known BPS rotating black hole solutions is obtained.Comment: 15 pages, Late

D=7 SU(2) Gauged Supergravity From D=10 Supergravity

The theory of SU(2) gauged seven-dimensional supergravity is obtained by compactifying ten dimensional N=1 supergravity on the group manifold SU(2).Comment: 10 pages. References added and some comments modifie

E-textbooks and connectivity: proposing an analytical framework

This paper is concerned with the development of e-textbooks. We claim that analysis (and design) of e-textbooks requires the development of a specific frame. Digital affordances provide particular opportunities (e.g. in terms of interactions between users) that require specific considerations for their analysis, as teachers and students use them for their individual and collective purposes. In this study, we develop a framework for mathematics e-textbook analysis, based on the notion of “connectivity.” We introduce criteria to assess the different aspects of connectivity and build an analysis grid for e-textbooks. We illustrate the framework proposed by analyzing 2 commonly used French grade 10 mathematics e-textbooks. The results of the analyses show that there are major differences between the 2 e-textbooks in terms of connectivity, which can be related to differences in their design. Beyond these 2 examples, we claim that focusing on connectivity is a useful and relevant way of analyzing e-textbooks, as it can provide a window into issues of interactivity, both practically and cognitively

FAKTOR-FAKTOR YANG MEMPENGARUHI AUDITOR SWITCHING SECARA VOLUNTARY PADA PERUSAHAAN MANUFAKTUR YANG TERDAFTAR PAD BURSA EFEK INDONESIA

This study aims to determine the effect of management change, audit opinion, client size and financial distress on voluntary auditor switching at manufacturing companies listed on the Indonesia Stock Exchange for the period 2010-2014. The population in this study are all manufacturing companies listed on the Indonesia Stock Exchange. The number of manufacturing companies that were sampled using the purposive sampling method was 64 companies for 5 years of observation. Hypothesis testing in this study uses logistic regression analysis. Based on the results of the logistic regression test, the results of this study indicate that the independent variable management change, audit opinion, client size and financial distress have a negative effect on the dependent variable auditor switching voluntarily

Interpolating from AdS_(D-2) X S^2 to AdS_D

We investigate a large class of supersymmetric magnetic brane solutions supported by U(1) gauge fields in AdS gauged supergravities. We obtain first-order equations in terms of a superpotential. In particular, we find systems which interpolate between AdS_{D-2}\times \Omega^2 (where \Omega^2=S^2 or H^2) in the horizon and AdS_D-type geometry in the asymptotic region, for 4\le D\le 7. The boundary geometry of the AdS_D-type metric is Minkowski_{D-3}\times \Omega^2. This provides smooth supergravity solutions for which the boundary of the AdS spacetime compactifies spontaneously. These solutions indicate the existence of a large class of superconformal field theories in diverse dimensions whose renormalization group flow runs from the UV to the IR fixed point. We show that the same set of first-order equations also admits solutions which are asymptotically AdS_{D-2}\times \Omega^2 but singular at small distance. This implies that the stationary AdS_{D-2}\times \Omega^2 solutions typically lie on the inflection points of the modulus space.Comment: Latex three times, 49 pages, 9 figure

From AdS Black Holes to Supersymmetric Flux-branes

We show that AdS black hole solutions admit an analytical continuation to become magnetic flux-branes. Although a BPS AdS black hole generally has a naked singularity, the BPS flux-brane can be regular everywhere with an appropriate choice of U(1)-charges. This flux-brane interpolates from AdS_{D-2} \times H^2 at small distance to an asymptotic AdS_D-type metric with an AdS_{D-2}\times S^1 boundary. We also obtain a smooth cosmological solution of de Sitter Einstein-Maxwell gravity which flows from dS_2\times S^{D-2} in the infinite past to a dS_D-type metric, with an S^{D-2}\times S^1 boundary, in the infinite future.Comment: Plain latex, 25 pages, references adde

Polarization Diagnostics for Cool Core Cluster Emission Lines

The nature of the interaction between low-excitation gas filaments at ~104 K, seen in optical line emission, and diffuse X-ray emitting coronal gas at ~107 K in the centers of galaxy clusters remains a puzzle. The presence of a strong, empirical correlation between the two gas phases is indicative of a fundamental relationship between them, though as yet of undetermined cause. The cooler filaments, originally thought to have condensed from the hot gas, could also arise from a merger or the disturbance of cool circumnuclear gas by nuclear activity. Here, we have searched for intrinsic line emission polarization in cool core galaxy clusters as a diagnostic of fundamental transport processes. Drawing on developments in solar astrophysics, direct energetic particle impact induced polarization holds the promise to definitively determine the role of collisional processes such as thermal conduction in the ISM physics of galaxy clusters, while providing insight into other highly anisotropic excitation mechanisms such as shocks, intense radiation fields, and suprathermal particles. Under certain physical conditions, theoretical calculations predict of the order of 10% polarization. Our observations of the filaments in four nearby cool core clusters place stringent upper limits ( 0.1%) on the presence of emission line polarization, requiring that if thermal conduction is operative, the thermal gradients are not in the saturated regime. This limit is consistent with theoretical models of the thermal structure of filament interfacesPeer reviewe

Solutions of Minimal Four Dimensional de Sitter Supergravity

Pseudo-supersymmetric solutions of minimal $N=2$, $D=4$ de Sitter supergravity are classified using spinorial geometry techniques. We find three classes of solutions. The first class of solution consists of geometries which are fibrations over a 3-dimensional manifold equipped with a Gauduchon-Tod structure. The second class of solution is the cosmological Majumdar-Papapetrou solution of Kastor and Traschen, and the third corresponds to gravitational waves propagating in the Nariai cosmology.Comment: 17 Pages. Minor correction to section 4; equation (4.21) corrected and (old) equation (4.26) deleted; the final result is unchange

Noncommutative Gravity in two Dimensions

We deform two-dimensional topological gravity by making use of its gauge theory formulation. The obtained noncommutative gravity model is shown to be invariant under a class of transformations that reduce to standard diffeomorphisms once the noncommutativity parameter is set to zero. Some solutions of the deformed model, like fuzzy AdS_2, are obtained. Furthermore, the transformation properties of the model under the Seiberg-Witten map are studied.Comment: 20 pages, LaTeX, references and some comments adde