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Malihe Heydari-Fard 《Astrophysics and Space Science》2010,325(2):287-292
Using the effective gravitational field equations in the warped DGP brane-world scenario (Maeda et al. in Phys. Rev. D 68:024033,
2003), we study spherically symmetric vacuum (static black hole) solutions on the brane. Working with a conformally flat bulk,
we have obtained an exact Schwarzschild–de Sitter black hole solution similar to the standard solution in the presence of
a cosmological constant, which confirms the idea that an extra term in the effective vacuum field equations on the warped
DGP brane can play the role of a positive cosmological constant. 相似文献
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A version of the virial theorem is derived in a brane-world scenario in the framework of a warped DGP model where the action on the brane is an arbitrary function of the Ricci scalar, $\mathcal{L}(R)$ . The extra terms in the modified Einstein equations generate an equivalent mass term (geometrical mass), which give an effective contribution to the gravitational energy and offer viable explanation to account for the virial mass discrepancy in clusters of galaxies. We also obtain the radial velocity dispersion of galaxy clusters and show that it is compatible with the radial velocity dispersion profile of such clusters. Finally, we compare the result of the model with $\mathcal{L}(R)$ gravity theories. 相似文献
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We investigate the influence of the cosmological constant, Λ, on the bending of light by a charged black hole in a de Sitter spacetime. Despite vanishing of the cosmological constant in the second order null geodesic equation, considering the method introduced by Rindler and Ishak (2007), we obtain an expression for the deflection angle, consistent with previous results for Schwarzschild, Schwarzschild-de Sitter (SdS), and Reissner-Nordstrom (RN) spacetimes. 相似文献
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