Related papers: String dynamics and ejection along the axis of a s…
We study conserved charges and thermodynamics of analytic rotating anti-de Sitter black holes with extended horizon topology -- also known as black strings -- in dynamical Chern-Simons modified gravity. The solution is supported by a scalar…
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…
The energy distribution associated with a stringy charged black hole is studied using M{\o}ller's energy-momentum complex. Our result is reasonable and it differs from that known in literature using Einstein's energy-momentum complex.
In this talk I review recent developments in superstring theory. In the first half of the talk I discuss some of the earlier developments in this subject. This includes a review of the status of string theory as a unified theory of gravity…
Using long-duration general relativistic magnetohydrodynamic simulations of radiatively inefficient accretion discs, the energy, momentum and mass outflow rates from such systems are estimated. Outflows occur via two fairly distinct modes:…
We classify the possible shapes of cosmic string cusps and how they transform under Lorentz boosts. A generic cusp can be brought into a form in which the motion of the cusp tip lies in the plane of the cusp. The cusp whose motion is…
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…
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 Regge trajectories, upon which string theory is based, behave as rigid rotators rather than vibrating strings. The same relation, between the angular momentum, and the square of the mass, can be found in gravity, the electroweak, and…
Strong gravity and magnetic fields are key ingredients that power processes of accretion and ejection near compact objects. While the particular mechanisms that operate here are still discussed, it seems that the presence of an ordered…
We demonstrate that all rigidly rotating strings with center of mass at the origin of the $dS_3$ static patch satisfy the Higuchi bound. This extends the observation of Noumi et al. for the open GKP-like string to all solutions of the…
The gravitational waves and energy radiations from a spinning compact object with stellar mass in a circular orbit in the equatorial plane of a supermassive Kerr black hole are investigated in this paper. The effect how the spin acts on…
We study the dynamics and escape of charged particles initially orbiting a weakly magnetized Kerr black hole after they get kicked in the direction normal to the orbit. The case of neutral particles is analysed first and the escape…
In this review we try to give a pedagogical introduction to the recent progress in the resolution of old problems of black hole thermodynamics within superstring theory. We start with a brief description of classical black hole dynamics.…
We investigate the energy distribution of a black hole in various spacetimes as reckoned by a distant observer using the quasi-local energy approach. In each case the horizon mass of a black hole: neutral, charged or rotating, is found to…
This thesis concerns the study of high-temperature string theory on curved backgrounds, generalizing the notions of Hagedorn temperature and thermal scalar to general backgrounds. Chapter 2 contains a review on string thermodynamics in flat…
The coupling of a string to gravity allows for Schwarzschild black holes whose entropy to area relation is $S=(A/4)(1-4\mu)$, where $\mu$ is the string tension. This departure from the A/4 universality results from a string instanton…
In the standard paradigm, astrophysical black holes can be described solely by their mass and angular momentum - commonly referred to as `spin' - resulting from the process of their birth and subsequent growth via accretion. Whilst the mass…
We develop the effective worldvolume theory for the dynamics of black branes with charges of the kind that arise in many supergravities and low-energy limits of string theory. Using this theory, we construct numerous new rotating black…
We discuss the correspondence between highly excited strings and black holes in the presence of angular momentum. At fixed imaginary angular velocity $\nu$, we show that free strings exhibit a Hagedorn instability due to a thermal-winding…