ar X iv : 0 80 8 . 08 80 v 1 [ gr - q c ] 6 A ug 2 00 8 Ricci flows , wormholes and critical phenomena

ar X iv : 0 80 8 . 24 81 v 1 [ he p - th ] 1 8 A ug 2 00 8 MIFP - 08 - 21 USTC - ICTS - 08 - 14 AdS

We obtain a large class of smooth Lorentzian p-brane wormholes in supergravities in various dimensions. They connect two asymptotically flat spacetimes. In cases where there is no dilaton involved in the solution, the wormhole can connect an AdSn × Sm in one asymptotic region to a flat spacetime in the other. We obtain explicit examples for (n,m) = (4, 7), (7, 4), (5, 5), (3, 3), (3, 2). These ...

ar X iv : 0 71 0 . 20 41 v 3 [ gr - q c ] 1 3 M ar 2 00 8 Thin - shell wormholes supported by ordinary matter in Einstein – Gauss – Bonnet gravity

The generalized Darmois–Israel formalism for Einstein–Gauss–Bonnet theory is applied to construct thin-shell Lorentzian wormholes with spherical symmetry. We calculate the energy localized on the shell, and we find that for certain values of the parameters wormholes could be supported by matter not violating the energy conditions.

ar X iv : 0 80 8 . 24 81 v 2 [ he p - th ] 1 6 O ct 2 00 8 MIFP - 08 - 21 USTC - ICTS - 08 - 14 AdS

We obtain a large class of smooth Lorentzian p-brane wormholes in supergravities in various dimensions. They connect two asymptotically flat spacetimes. In cases where there is no dilaton involved in the solution, the wormhole can connect an AdSn × Sm in one asymptotic region to a flat spacetime in the other. We obtain explicit examples for (n,m) = (4, 7), (7, 4), (5, 5), (3, 3), (3, 2). These ...

ar X iv : 0 80 8 . 10 23 v 1 [ qu an t - ph ] 7 A ug 2 00 8 CATEGORICAL QUANTUM MECHANICS

ar X iv : 0 80 5 . 45 05 v 2 [ gr - q c ] 1 5 A ug 2 00 8 Kerr initial data

Exploiting a 3+1 analysis of the Mars-Simon tensor, conditions on a vacuum initial data set ensuring that its development is isometric to a subset of the Kerr spacetime are found. These conditions are expressed in terms of the vanishing of a positive scalar function defined on the initial data hypersurface. Applications of this result are discussed. PACS numbers: 04.20.Ex, 04.20-q, 04.70-s Subm...