In this article we briefly review the attractor mechanism in the context of N= 2 supergravity theories arising from the compactification of type-. IIA string theory on a Calabi-Yau manifold. We find non-supersymmetric attractors and discuss their stability. We further discuss the generalization of the attractor mechanism to N= 2 gauged supergravity and explicitly construct configurations corresponding to Bianchi attractors. © 2014 Elsevier B.V.

Prasanta Kumar Tripathy

Department Of Physics

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IIT Madras

Nuclear Physics B - Proceedings Supplements

In this paper, we analyse the stability of extremal black brane horizons with homogeneous symmetry in the spatial directions in five dimensional gauged supergravity, under the fluctuations of the scalar fields about their attractor values. We examine the scalar fluctuation equations at the linearised level and demand that the fluctuations vanish as one approaches the horizon. Imposing certain restrictions on the Killing vectors used for gauging we find that the necessary conditions for stability are satisfied only by a subclass of the Bianchi metrics whose symmetry group factorises into a two dimensional Lifshitz symmetry and any homogeneous symmetry group given by the Bianchi classification. We apply these results to a simple example of a gauged supergravity model with one vector multiplet to find the stable attractors.

Fulltext

Journal of High Energy Physics

Stability of Bianchi attractors in gauged supergravity

In this paper we examine the stability of non-supersymmetric attractors in type IIA supergravity compactified on a Calabi-Yau manifold, in the presence of sub-leading corrections to the N = 2 pre-potential. We study black hole configurations carrying D0-D6 and D0-D4 charges. We consider the O(1) corrections to the pre-potential given by the Euler number of the Calabi-Yau manifold. We argue that such corrections in general can not lift the zero modes for the D0-D6 attractors. However, for the attractors carrying the D0-D4 charges, they affect the zero modes in the vector multiplet sector. We show that, in the presence of such O(1) corrections, the D0-D4 attractors can either be stable or unstable depending on the geometry of the underlying Calabi-Yau manifold, and on the specific values of the charges they carry. © SISSA 2012.

Non-supersymmetric stringy attractors

In this paper we study generalized attractors in N = 2 gauged supergravity theory in five dimensions coupled to arbitrary number of hyper, vector and tensor multiplets. We look for attractor solutions with constant anholonomy coefficients. By analyzing the equations of motion we derive the attractor potential. We further show that the generalized attractor potential can be obtained from the fermionic shifts. We study some simple examples and show that constant anholonomy gives rise to homogeneous black branes in five dimensions. © SISSA 2012.

Generalized attractors in five-dimensional gauged supergravity

We discuss non-supersymmetric attractors with an instanton correction in Type IIA string theory compactified on a Calabi-Yau three-fold at large volume. For a stable non-supersymmetric black hole, the attractor point must minimize the effective black hole potential. We study the supersymmetric as well as non-supersymmetric attractors for the D0-D4 system with instanton corrections. We show that in simple models, like the STU model, the flat directions of the mass matrix can be lifted by a suitable choice of the instanton parameters. © SISSA 2011.

Journal	Data powered by TypesetNuclear Physics B - Proceedings Supplements
Publisher	Data powered by TypesetElsevier
ISSN	09205632
Open Access	No