Related papers: Cosmic Strings and Black Holes
We argue that the infinitely many gauge symmetries of string theory provide an infinite set of conserved (gauge) quantum numbers (W-hair) which characterise black hole states and maintain quantum coherence, even during exotic processes like…
We construct hairy static black holes of higher dimensional general coupling Einstein-Skyrme theories with the scalar potential turned on and the cosmological constant is non-positive in which the scalar multiplets satisfy $O(d+1)$ model…
In this paper, we consider the quantum area spectrum for a rotating and charged (Kerr-Newman) black hole. Generalizing a recent study on Kerr black holes (which was inspired by the static-black hole formalism of Barvinsky, Das and…
It is presented an exact solution of straight spinning cosmic strings in Brans-Dicke theory of gravitation. The possibility of the existence of closed timelike curves around these cosmic strings is analyzed. Furthermore, the stability about…
We investigate properties of two-dimensional asymptotically flat black holes which arise in both string theory and in scale invariant theories of gravity. By introducing matter sources in the field equations we show how such objects can…
Field equations of a classical, geometric, theory of gravity, augmented with some semiclassical considerations strongly suggest that the gravitational field representing a stationary black hole can be simply described with a few…
We review recent developments in understanding quantum/string corrections to BPS black holes and strings in five-dimensional supergravity. These objects are solutions to the effective action obtained from M-theory compactified on a…
It was reported that Kerr-Newman black holes can support linear charged scalar fields in their exterior regions. These stationary massive charged scalar fields can form bound states, which are called stationary scalar clouds. In this paper,…
We discuss the form of the string-loop-corrected effective action and the loop-corrected solutions of the equations of motion. At the string-tree level, a solution we consider is the extremal magnetic black hole, in which case the…
On the basis of an area-preserving symmetry in the phase space of a one-dimensional matrix model - believed to describe two-dimensional string theory in a black-hole background which also allows for space-time foam - we give a geometric…
We study the first-order $\alpha'$ corrections to the singular 4-dimensional massless stringy black holes studied in the nineties in the context of the Heterotic Superstring. We show that the $\alpha'$ corrections not only induce a…
The exact black hole solution of 2D closed string theory has, as any other maximally extended Schwarzschild-like geometry, two asymptotically flat spacetime domains. One can get rid of the second domain by gauging the discrete symmetry on…
We discuss basic features of the model of spinning particle based on the Kerr solution. It contains a very nontrivial {\it real} stringy structure consisting of the Kerr circular string and an axial stringy system. We consider also the…
In spacetimes with compact dimensions there exist several black object solutions including the black-hole and the black-string. These solutions may become unstable depending on their relative size and the relevant length scale set by the…
In this paper we investigate whether the holographic principle proposed in string theory has a classical counterpart in general relativity theory. We show that there is a partial correspondence: at least in the case of vacuum Petrov type D…
We present a new solution describing a pair of rotating, charged, and accelerating black holes in in the low energy limit of heterotic string theory. To obtain the solution, we apply the Hassan-Sen transformation to the neutral accelerating…
Motivated by the recent interest on models with varying constants and whether black hole physics can constrain such theories, two-dimensional charged stringy black holes are considered. We exploit the role of two-dimensional stringy black…
We uplift the static three dimensional black hole solution found by Banados, Teitelboim and Zanelli (BTZ) into four dimensional space time. In this way we obtain a black string solution with a relativistic string source, as well as a new…
We study the emergence of string instabilities in $D$ - dimensional black hole spacetimes (Schwarzschild and Reissner - Nordstr\o m), and De Sitter space (in static coordinates to allow a better comparison with the black hole case). We…
$U(1)$ zero modes in the $SL(2,R)_k/U(1)$ and $SU(2)_k/U(1)$ conformal coset theories, are investigated in conjunction with the string black hole solution. The angular variable in the Euclidean version, is found to have a double set of…