Tetsuya Shiromizu

Uniqueness and non-uniqueness of static vacuum black holes in higher dimensions

We prove a uniqueness theorem for asymptotically flat static charged dilaton black hole solutions in higher dimensional space-times. We also construct infinitely many non-asymptotically flat regular static black holes on the same space-time manifold with the same spherical topology. An application to the uniqueness of a certain class of flat

Low energy effective theory for a two branes system: Covariant curvature formulation

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Galaxy clustering constraints on deviations from Newtonian gravity at cosmological scales

-branes is also given.

A cosmological constant limits the size of black holes

We derive the low energy effective theory for two branes system solving the bulk geometry formally in the covariant curvature formalism developed by Shiromizu, Maeda and Sasaki. As expected, the effective theory looks like a Einstein-scalar system. Using this theory we can discuss the cosmology and non-linear gravity at low energy scales.

Asymptotic flatness at null infinity in arbitrary dimensions

In spite of the growing observational evidence for dark matter and dark energy in the universe, their physical nature is largely unknown. In fact, several authors have proposed modifications of Newtons law of gravity at cosmological scales to account for the apparent acceleration of the cosmic expansion. Inspired by such suggestions, we attempt to constrain possible deviations from Newtonian gravity by means of the clustering of SDSS (Sloan Digital Sky Survey) galaxies. To be specific, we assume a simple modification of Newtons law with an additional Yukawa-type term characterized by the amplitude

Low energy effective theory on a regularized brane in 6D gauged chiral supergravity

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On asymptotic structure at null infinity in five dimensions

and the length scale

Primordial magnetic fields from second-order cosmological perturbations: tight coupling approximation

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Cosmological magnetic fields from nonlinear effects

. Adopting spatially-flat universes dominated by cold dark matter and/or dark energy, we solve a linear perturbation equation for the growth of density fluctuations. In particular, we find an exact analytic solution for the Einstein-de Sitter case. Following the Peacock-Dodds prescription, we compute the nonlinear power spectra of mass fluctuations, perform a statistical comparison with the SDSS galaxy data, and derive constraints in the

Primordial magnetic field from non-inflationary cosmic expansion in Horava-Lifshitz gravity

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