A toroidal proposal for the Rotating Black Hole model (original) (raw)
Geometry of charged rotating black hole
Some geometrical aspects of the Kerr-Newman black hole and its special cases have been studied. It is seen that the Gaussian curvature of the two or three dimensional induced metrics on some hypersurfaces outside of these black holes can be expressed in terms of the eigen values of the characteristic equation and depend upon the physical parameters which describe these black holes.
Classical and Quantum Gravity, 2010
In this paper we construct four Kerr-like spacetimes starting from the loop black hole Schwarzschild solutions (LBH) and applying the Newman-Janis transformation. In previous papers the Schwarzschild LBH was obtained replacing the Ashtekar connection with holonomies on a particular graph in a minisuperspace approximation which describes the black hole interior. Starting from this solution, we use a Newman-Janis transformation and we specialize to two different and natural complexifications inspired from the complexifications of the Schwarzschild and Reissner-Nordstrom metrics. We show explicitly that the space-times obtained in this way are singularity free and thus there are no naked singularities. We show that the transformation move, if any, the causality violating regions of the Kerr metric far from r=0. We study the space-time structure with particular attention to the horizons shape. We conclude the paper with a discussion on a regular Reissner-Nordstrom black hole derived from the Schwarzschild LBH and then applying again the Newmann-Janis transformation.
Black holes with toroidal horizons in ( d+1$$ d + 1 )-dimensional space-time
General Relativity and Gravitation
We investigate black holes with toroidal horizons in (d + 1)-dimensional space-time. Using the solution phase space method, we calculated conserved charges for these black holes before exploring some features of this metric including its entropy and thermodynamic quantities. Another aspect of the study involves obtaining a general exact static interior solution for uncharged black holes with toroidal horizons in (d + 1)-dimensional space-time. Finally, an interior solution for charged black holes is obtained.
Rotating Black Holes, Complex Geometry, and Thermodynamics, b
Annals of The New York Academy of Sciences, 1991
In recent years the proposal' to relate the Euclidean action of black holes to approximations of certain functional integrals that can be interpreted as thermodynamic partition functions has been developed extensively. In this paper we outline briefly the key points of these developments and extend them to the treatment of stationary geometries, in particular the geometries of rotating black holes. Stationary holes are ostensibly more difficult to handle than static ones, primarily because neither the extrinsic curvature of the stationary constant-time slices nor the corresponding shift vector vanishes, while both do vanish in the case of static geometries. Consequently, as we shall see, there is no real Euclidean metric that represents a rotating black hole. Nevertheless, the hole can be described by a complex geometry that is an extremum of an appropriate real action-we shall call it the thermodynamical action.
Rotating black holes, global symmetry and first order formalism
Journal of High Energy Physics, 2012
In this paper we consider axisymmetric black holes in supergravity and address the general issue of defining a first order description for them. The natural setting where to formulate the problem is the De Donder-Weyl-Hamilton-Jacobi theory associated with the effective two-dimensional sigma-model action describing the axisymmetric solutions. We write the general form of the two functions S m defining the first-order equations for the fields. It is invariant under the global symmetry group G (3) of the sigma-model. We also discuss the general properties of the solutions with respect to these global symmetries, showing that they can be encoded in two constant matrices belonging to the Lie algebra of G (3) , one being the Nöther matrix of the sigma model, while the other is non-zero only for rotating solutions. These two matrices allow a G (3)-invariant characterization of the rotational properties of the solution and of the extremality condition. We also comment on extremal, under-rotating solutions from this point of view.
Rotating Black Holes in Unified Theories
Progress of Theoretical Physics Supplement, 1999
Some remarkable properties of the supersymmetric five-dimensional rotating solutions of Beckenridge, Myers, Peet and Vafa are described. The solutions may be under-rotating, in which case they are extreme black holes or over-rotating, in which case they are naked time machines. The geodesics and global structure of the spacetime are analysed, including the possibility of time travel by freely falling observers. I argue, following recent work with C. Herdeiro, that the over-rotating solutions cannot be reached from the under-rotating black hole solutions by a physical process using a finite amount of energy. This would fit in with the Chronology Protection conjecture.
2 The interior structure of rotating black holes 1. Concise derivation
2012
This paper presents a concise derivation of a new set of solutions for the interior structure of accreting, rotating black holes. The solutions are conformally stationary, axisymmetric, and conformally separable. Hyper-relativistic counter-streaming between freely-falling collisionless ingoing and outgoing streams leads to mass inflation at the inner horizon, followed by collapse. The solutions fail at an exponentially tiny radius, where the rotational motion of the streams becomes comparable to their radial motion. The papers provide a fully nonlinear, dynamical solution for the interior structure of a rotating black hole from just above the inner horizon inward, down to a tiny scale.