Related papers: Self-gravitating fundamental strings and black-hol…
The string-black hole correspondence principle can be investigated in the non-BPS scenario by studying the string configuration and entropy when the string coupling is slowly increased. Through a rigorous analysis, it is shown how an…
In this paper, we make a systematical and in-depth study on the chaotic dynamics of the string around the conformal black hole. Depending on the characteristic parameter of the conformal black hole and the initial position of the string,…
Ultrahigh-energy string scattering is investigated to clarify the relative role of string and gravitational effects, and their possible contributions to nonlocal behavior. Different regimes can be characterized by varying the impact…
We examine the field equations of a self-gravitating global string in low energy superstring gravity, allowing for an arbitrary coupling of the global string to the dilaton. Massive and massless dilatons are considered. For the massive…
An effective string theory in physically relevant cosmological and black hole space times is reviewed. Explicit computations of the quantum string entropy, partition function and quantum string emission by black holes (Schwarzschild,…
We study a class of fluctuating higher dimensional black hole configurations obtained in string theory/ $M$-theory compactifications. We explore the intrinsic Riemannian geometric nature of Gaussian fluctuations arising from the Hessian of…
For most black holes in string theory, the Schwarzschild radius in string units decreases as the string coupling is reduced. We formulate a correspondence principle, which states that (i) when the size of the horizon drops below the size of…
Massless BPS-saturated states in toroidally compactified heterotic string were discussed first. Then, I constructed a large class of BPS-saturated states of toroidally compactified type II string theories. They were parametrized by four…
We show that string theory in AdS3 has two distinct phases depending on the radius of curvature R_{AdS}=\sqrt{k}l_s. For k>1 (i.e. R_{AdS}>l_s), the SL(2,C) invariant vacuum of the spacetime conformal field theory is normalizable, the high…
We calculate the density of states with given mass and spin in string theory and obtain asymptotic formulas. We also compute the tree-level gyromagnetic couplings for arbitrary physical states in the heterotic string theory. These results…
This paper discusses the gravitational scattering of a straight, infinitely long test cosmic string by a black hole. We present numerical results that probe the two-dimensional parameter space of impact parameter and initial velocity and…
Based on well-known properties of semi-classical black holes, we show that weakly-coupled string theory can be viewed as a theory of N = 1/g_s^2 particle species. This statement is a string theoretic realization of the fact that the…
This thesis investigates two main topics concerning black holes in extensions of general relativity inspired by string theory. First, the structure of the equations of motion underlying black hole solutions is considered, in theories of…
The fundamental heterotic string has a tower of BPS states whose supersymmetric index has an exponential growth in the charges. We construct the saddle-point of the gravitational path integral corresponding to this index. The saddle-point…
We consider four-graviton scattering in Type II string theory on one-loop level in the large centre of mass energy M^2 limit. We extract from it an explicit integral expression for the full string theory corrections to the imaginary part of…
The correspondence principle between strings and black holes is a general framework for matching black holes and massive states of fundamental strings at a point where their physical properties (such as mass, entropy and temperature)…
Following the work of Sen, we consider the correspondence between extremal black holes and string states in the context of the entropy. We obtain and study properties of electrically charged black hole backgrounds of tree level heterotic…
We investigate the geometry of four dimensional black hole solutions in the presence of stringy higher curvature corrections to the low energy effective action. For certain supersymmetric two charge black holes these corrections drastically…
We study aspects of four dimensional black holes with two electric charges, corresponding to fundamental strings with generic momentum and winding on an internal circle. The perturbative \alpha' correction to such black holes and their…
In string theory, black holes can be made from brane systems that are partially delocalized in string theory's extra dimensions. It is expected that they correspond to an ensemble of pure, horizonless microstates sourced by localized…