Paper (*cross-listing*): gr-qc/0605018
Date: Tue, 2 May 2006 16:13:51 GMT (510kb)

Title: Hydro-without-Hydro Framework for Simulations of Black Hole-Neutron Star
Binaries

Authors: Carlos F. Sopuerta (1), Ulrich Sperhake (1 and 2), and Pablo Laguna
(1) ((1) CGWP, Penn State, (2) TPI, Jena)

Comments: 16 pages, 7 figures. To appear in the Classical and Quantum Gravity
special issue on Numerical Relativity
\\
We introduce a computational framework which avoids solving explicitly
hydrodynamic equations and is suitable to study the pre-merger evolution of
black hole-neutron star binary systems. The essence of the method consists of
constructing a neutron star model with a black hole companion and freezing the
internal degrees of freedom of the neutron star during the course of the
evolution of the space-time geometry. We present the main ingredients of the
framework, from the formulation of the problem to the appropriate computational
techniques to study these binary systems. In addition, we present numerical
results of the construction of initial data sets and evolutions that
demonstrate the feasibility of this approach.

\\ ( http://arXiv.org/abs/gr-qc/0605018 , 510kb)

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Paper (*cross-listing*): hep-th/0605031
Date: Wed, 3 May 2006 05:16:04 GMT (32kb)

Title: Kaluza-Klein black hole with negatively curved extra dimensions in
string generated gravity models

Authors: Hideki Maeda and Naresh Dadhich

Comments: 4 pages, 2 figures
\\
We obtain a new exact black-hole solution in Einstein-Gauss-Bonnet gravity
with a cosmological constant which bears a specific relation to the
Gauss-Bonnet coupling constant. The spacetime is a product of the usual
4-dimensional manifold with a $(n-4)$-dimensional space of constant negative
curvature, i.e., its topology is locally ${\ma M}^n \approx {\ma M}^4 \times
{\ma H}^{n-4}$. The solution has two parameters and asymptotically approximates
to the field of a charged black hole in anti-de Sitter spacetime. The most
interesting and remarkable feature is that the Gauss-Bonnet term acts like a
Maxwell source for large $r$ while at the other end it regularizes the metric
and weakens the central singularity.

\\ ( http://arXiv.org/abs/hep-th/0605031 , 32kb)