Spinning Higher Dimensional Einstein-Yang-Mills black holes

We construct a Kerr-Newman-like spacetimes starting from higher dimensional (HD) Einstein-Yang-Mills black holes via complex transformations suggested by Newman-Janis. The new metrics are HD generalization of Kerr-Newman spacetimes which has a geometry precisely that of Kerr-Newman in 4D corresponding to Yang-Mills (YM) gauge charge, but the sign of charge term gets flipped in the HD spacetimes. It is interesting to note that gravitational contribution of YM gauge charge, in HD, is indeed opposite (attractive rather than repulsive) that of Maxwell charge. The effect of YM gauge charge on the structure and location of static limit surface and apparent horizon is discussed. We find that static limit surfaces become less prolate with increase in dimensions and are also sensitive to YM gauge charge thereby affecting the shape of ergosphere. We also analyze some thermodynamical properties of these BHs.Comment: Accepted for publication in EPJ

Radiating Kerr–Newman black hole in

We derive an exact radiating Kerr–Newman like black hole solution, with constant curvature R=R 0 imposed, to metric f(R) gravity via complex transformations suggested by Newman–Janis. This generates a geometry which is precisely that of radiating Kerr–Newman–de Sitter/anti-de Sitter with the f(R) gravity term R 0 contributing a cosmological-like term. The structure of three horizon-like surfaces, viz. time-like limit surface, apparent horizon, and event horizon, are determined. We demonstrate the existence of an additional cosmological horizon, in f(R) gravity model, apart from the regular black hole horizons that exist in the analogous general relativity case. In particular, the known stationary Kerr–Newman black hole solutions of f(R) gravity and general relativity are retrieved. We find that the time-like limit surface becomes less prolate with R 0 thereby affecting the shape of the corresponding ergosphere

Optical and thermodynamic properties of a rotating dyonic black hole spacetime in

The null geodesics and the distance of closest approach for photon around a rotating dyonic black hole in $${\mathcal {N}} = 2, U(1)^2$$ gauged supergravity is studied. The phenomenon of black hole shadows with various black hole parameters has also analyzed. Further, the investigation of various thermodynamic properties for this black hole is performed with various thermodynamic parameters at the horizon. The heat capacity to study the thermodynamic stability of this black hole spacetime is also studied. The influence for different values of the black hole parameters $$\nu$$, e, $$\nu$$, g and $$N_{g}$$ on the phenomenon of black hole shadows and thermodynamic parameters is also investigated visually