Related papers: String propagation in four-dimensional dyonic blac…
It is expected that when the string coupling is taken to be sufficiently small, a black hole turns into a bound state of self-gravitating fundamental strings. This state would be described by winding strings wrapping around the Euclidean…
Instead of the infinitesimal extrinsic and intrinsic perturbations on strings, considered so far, we discuss the evolution and propagation of finite-amplitude perturbations. Those intrinsic perturbations may result in appearance of stable…
Progress on the physics of strings in curved spacetime are comprehensively reviewed.We start by showing through renormalization group arguments that a meaningful quantum theory of gravity must be finite and must include all particle…
We consider the evolution of a scalar field coupled to curvature in topological black hole spacetimes. We solve numerically the scalar wave equation with different curvature-coupling constant $\xi$ and show that a rich spectrum of wave…
We study various rotating and oscillating D-string configurations in some general backgrounds with fluxes. In particular, we look for solutions to the equations of motion of various rigidly rotating D-strings in $AdS_3$ background with…
We discuss how cosmic strings can be used to mine energy from black holes. A string attached to the black hole gives rise to an additional channel for the energy release. It is demonstrated that when a string crosses the event horizon, its…
We consider the physical properties of four dimensional black hole solutions to the effective action describing the low energy dynamics of the gravitational sector of heterotic superstring theory. We compare the properties of the external…
We provide an explicit construction of classical strings that have endpoints on the horizons of the 2D Lorentzian black hole. We argue that this is a dual description of geodesics that are localized around the horizon which are the…
We give an exact description of the steady flow of a black string into a planar horizon. The event horizon is out of equilibrium and provides a simple, exact instance of a `flowing black funnel' in any dimension D>=5. It is also an…
We examine background solutions of black hole type arising from the string effective action in five dimensions. We derive the unique metric - dilaton vacuum which is a Schwarzschild type black hole. It is found that it can be extended to…
We examine the geometry near the event horizon of a family of black string solutions with traveling waves. It has previously been shown that the metric is continuous there. Contrary to expectations, we find that the geometry is not smooth,…
We derive a precise dictionary between micro-state geometries and open string condensates for a large class of excitations of four dimensional BPS black holes realised in terms of D3-branes intersecting on a six-torus. The complete…
We discuss the propagation of scalars in a large class of non-extremal black hole and black p-brane geometries in generic dimensions. We show that the radial wave equation near the horizon possesses the SL(2,R) structure in every case;…
We find several classes of exact classical solutions of critical bosonic string theory, constructed as twisted products of one Euclidean and one Minkowskian 2D black hole coset. One class of these solutions leads (after tensoring with free…
The perturbative modes propagating along an infinite string are investigated within the framework of the gauge invariant perturbation formalism on a spacetime containing a self-gravitating straight string with a finite thickness. These…
In this paper we study the stability of an homogeneous black string in the presence of a negative cosmological constant with minimally coupled scalar fields by using the large $D$ effective theory. This method allows us to explore the…
We investigate quantum aspects of the three dimensional (BTZ) black holes. The discussions are devoted to two subjects: the thermodynamics of quantum scalar fields and the string theory in the three dimensional black hole backgrounds. We…
String theory on curved backgrounds has received much attention on account of both its own interest, and of its relation with gauge theories. Despite the progress made in various directions, several quite elementary questions remain…
We investigate the connection between curved spacetime and the emergence of string-instabilities, following the approach developed by Loust\'{o} and S\'{a}nchez for de Sitter and black hole spacetimes. We analyse the linearised equations…
We find exact solutions of the Einstein equations which describe a black hole pierced by infinitely thin cosmic strings. The string segments enter the black hole along the radii and their positions coincide with the symmetry axes of a…