arXiv subjects
Publications and source records attributed to E. Radu.
We present new solutions of the $d=5$ Einstein-Yang-Mills theory describing black holes with squashed horizons. These configurations are asymptotically locally flat and have a boundary topology of a fibre bundle $R\times S^1 \hookrightarrow S^{2}$. In a $d=4$ picture, they describe black hole solutions with both nonabelian and U(1) magnetic charges.
We present arguments for the existence of a new type of solutions of the Euclidean Einstein-Yang-Mills-dilaton theory in $d=4$ dimensions. Possesing nonvanishing nonabelian charges, these nonselfdual configurations have no counterparts on the Lorentzian section. They provide, however, new saddle points in the Euclidean path integral.
We study two classes of static uniform black string solutions in a (4+1)-dimensional SU(2) Einstein-Yang-Mills model. These configurations possess a regular event horizon and corresponds in a 4-dimensional picture to axially symmetric black hole solutions in an Einstein-Yang-Mills-Higgs-U(1)-dilaton theory. In this approach, one set of solutions possesses a nonzero magnetic charge, while the other solutions represent black holes located in between a monopole-antimonopole pair. A detailed analysis of the solutions' properties is presented, the domain of existence of the black strings being determined. New four dimensional solutions are found by boosting the five dimensional configurations. We also present an argument for the non-existence of finite mass hyperspherically symmetric black holes in SU(2) Einstein-Yang-Mills theory.
Some properties of an exact solution due to Vaidya, describing the gravitational field produced by a point particle in the background of the static Einstein universe are examined. The maximal analytic extension and the nature of the singularities of the model are discussed. By using the Euclidean approach, some quantum aspects are analysed and the thermodynamics of this spacetime is also discussed.