Related papers: Macroscopic open strings and gravitational confine…
We consider Kaluza-Klein models where internal spaces are compact flat or curved Einstein spaces. This background is perturbed by a compact gravitating body with the dust-like equation of state (EoS) in the external/our space and an…
Supergravity brane solutions allow for a generalised type of Kaluza-Klein reduction onto brane worldvolumes. The known replacement of a flat worldvolume metric by a Ricci-flat metric constitutes a consistent Kaluza-Klein truncation of the…
I solve the equations of the low-energy limit of string theory to obtain a solution corresponding to a microcanonical ensemble of highly-excited superstrings. This ``Superball of Strings'' is a static, spherically symmetric ``fuzzball'' of…
We consider a five-dimensional Einstein-Gauss-Bonnet model, which gives rise after dimensional reduction to Einstein gravity nonminimally coupled to nonlinear electrodynamics. The black hole solutions of the four-dimensional model modify…
We point out that in heterotic string theory compactified on a 6-torus, after a consistent truncation of the 10-d gauge fields and the antisymmetric tensor fields, 4-dimensional black holes of Kaluza-Klein theory on a 6-torus constitute a…
We make a systematic investigation of stationary cylindrically symmetric solutions to the five-dimensional Einstein and Einstein-Gauss-Bonnet equations. Apart from the five-dimensional neutral cosmic string metric, we find two new exact…
We make an attempt to dynamically study, in four space-time dimensions, the classical gravitational collapse of a macroscopic circular fundamental string, by a truncation of the Einstein equations that suppresses retarded features but keeps…
We obtain a class of slowly rotating charged Kaluza-Klein black hole solutions of the five-dimensional Einstein-Maxwell-dilaton theory with arbitrary dilaton coupling constant. At infinity, the spacetime is effectively four-dimensional. In…
Under the spirit of J. Polchinsky's introduction of D-brane in the string target spacetime (or 'bulk', for short), we consider the presence of both closed and open superstrings and coupling of their low-lying modes in the bulk. As a probe…
Supersymmetric closed string theories contain an infinite tower of BPS-saturated, oscillating, macroscopic strings in the perturbative spectrum. When these theories have dual formulations, this tower of states must exist nonperturbatively…
We review various aspects of classical solutions in string theories. Emphasis is placed on their supersymmetry properties, their special roles in string dualities and microscopic interpretations. Topics include black hole solutions in…
We study the thermodynamics of the 4-dimensional electrically charged black-hole solutions of the simplest 5-dimensional Kaluza-Klein theory using Wald's formalism. We show how the electric work term present in the 4-dimensional first law…
Four-dimensional homogeneous static and rotating black strings in dynamical Chern-Simons modified gravity, with and without torsion, are presented. Each solution is supported by a scalar field that depends linearly on the coordinate that…
We consider a Kaluza-Klein vacuum solution which is closely related to the Gross-Perry-Sorkin (GPS) magnetic monopole. The solution can be obtained from the Euclidean Taub-NUT solution with an extra compact fifth spatial dimension within…
If the graviton possesses an arbitrarily small (but nonvanishing) mass, perturbation theory implies that cosmic strings have a nonzero Newtonian potential. Nevertheless in Einstein gravity, where the graviton is strictly massless, the…
The possible transition of large mass magnetic monopole solutions to monopole black hole solutions in Yang-Mills-Higgs theory with spontaneous symmetry breaking (SSB) coupled to the low energy effective theory of superstring with only…
Time-dependent solutions of supergravity and string theory are studied. The examples are obtained from de Sitter deformation of gauge/gravity dualities, analytical continuation of static solutions, and ``exactly solvable'' worldsheet…
Integrability of classical strings in the BTZ black hole enables the construction and study of classical string propagation in this background. We first apply the dressing method to obtain classical string solutions in the BTZ black hole.…
It is shown that in the standard vacuum 5D Kaluza-Klein gravity there is wormhole-like solutions which look like strings attached to two D-branes. The asymptotical behaviour of the corresponding metric is investigated.
We discuss the possible applications of string theory for the construction of generalizations of the $SU(3)\times SU(2)\times U(1)$ standard model of strong and electroweak interactions. This includes an investigation of effective $d=4$…