Dmitri V. Gal’tsov

Linear dilaton black holes

We present new solutions to Einstein-Maxwell-dilaton-axion (EMDA) gravity in four dimensions describing black holes which asymptote to the linear dilaton background. In the non-rotating case they can be obtained as the limiting geometry of dilaton black holes. The rotating solutions (possibly endowed with a NUT parameter) are constructed using a generating technique based on the Sp(4,R) duality of the EMDA system. In a certain limit (with no event horizon present) our rotating solutions coincide with supersymmetric Israel-Wilson-Perjes type dilaton-axion solutions. In presence of an event horizon supersymmetry is broken. The temperature of the static black holes is constant, and their mass does not depend on it, so the heat capacity is zero. We investigate geodesics and wave propagation in these spacetimes and find superradiance in the rotating case. Because of the non-asymptotically flat nature of the geometry, certain modes are reflected from infinity, in particular, all superradiant modes are confined. This leads to classical instability of the rotating solutions. The non-rotating linear dilaton black holes are shown to be stable under spherical perturbations.

Radiation reaction in various dimensions

We discuss the radiation reaction problem for an electric charge moving in flat space-time of arbitrary dimensions. It is shown that four is the unique dimension where a local differential equation exists accounting for the radiation reaction and admitting a consistent mass renormalization (the Lorentz-Dirac equation). In odd dimensions Huygenss principle does not hold, and, as a result, the radiation reaction force depends on the whole past history of a charge (radiative tail). We show that the divergence in the tail integral can be removed by the mass renormalization only in the

Supergravity fluxbranes in various dimensions

2+1

Supergravity p-branes reexamined: Extra parameters, uniqueness, and topological censorship

theory. In even dimensions higher than four, divergences cannot be removed by the mass renormalization.

Radiation Reaction and Energy–Momentum Conservation

We investigate fluxbrane solutions to the Einstein-antisymmetric form-dilaton theory in arbitrary space-time dimensions for a transverse space of cylindrical topology

Oxidation ofD=3cosets and Bonnor dualities inD≤6

{S}^{k}\ifmmode\times\else\texttimes\fi{}{R}^{n},

New Features about Chaos in Bianchi I non‐Abelian Born‐Infeld cosmology

corresponding to smeared and unsmeared solutions. A master equation for a single metric function is derived. This is a non-linear second-order ordinary differential equation admitting an analytic solution, singular at the origin, which serves as an attractor for globally regular solutions, whose existence is demonstrated numerically. For all fluxbranes of different levels of smearing the metric function diverges at infinity as the same power of the radial coordinate except for the maximally smeared case, where a global solution is known in closed form and can be obtained algebraically using U duality. The particular cases of

Radiation Reaction of Charged Particles Orbiting a Magnetized Schwarzschild Black Hole

F6

Gravitational and dilaton radiation from a relativistic membrane

and

Piercing of domain walls: new mechanism of gravitational radiation

F3