Related papers: Exact Primordial Black Strings in Four Dimensions
We present new solutions of the string cosmological effective action in the presence of a homogeneous Maxwell field with pure magnetic component. Exact solutions are derived in the case of space-independent dilaton and vanishing torsion…
We reconsider here the problem of finding the general 4D spherically symmetric, asymptotically flat and time-independent solutions to the lowest-order string equations in the $\ap$ expansion. Our construction includes earlier work, but…
Four-dimensional compactifications of string theory provide a controlled set of possible gauge representations accounting for BSM particles and dark sector components. In this review, constraints from perturbative Type II string…
Starting from an exact (in the Regge slope alpha') functional method for a bosonic stringy sigma-model, we investigate four-dimensional cosmological string solutions in graviton, dilaton and antisymmetric tensor backgrounds, compatible with…
In the present work, we study four-dimensional black strings in Horndeski models with translation invariance. Imposing that the scalar field depends on the string-generator coordinate, the Klein-Gordon equation admits a linear profile as a…
In string theory, an important challenge is to show if the singularity of black holes can be smoothed out by the complete $\alpha^{\prime}$ corrections. The simplest case is to consider a 2D string black hole or 3D black string. This…
We provide a new five dimensional black string--like solution by means of the embedding of a four dimensional regular black hole into a compact extra dimension. We enunciate a list of constraints in order to that the five dimensional black…
We reviewed the Ba\u nados-Teitelboim-Zanelli (BTZ) black hole solution in connection with the spinning string solution. We find a new exact solution, which can be related to the $(2+1)$-dimensional spinning point particle solution. There…
New exact solutions of Einstein equations which describe black hole with radial cosmic strings are constructed in the paper. The case of infinitely thin strings and the case of delocalized strings are considered. The case of delocalized…
Recent progress on string theory in curved spacetimes is reviewed. The string dynamics in cosmological and black hole spacetimes is investigated.The methods to solve the string equations of motion in curved spacetimes are described.That is,…
A string action is considered in four spacetime dimensions which is obtained by dimensionally reducing the ten dimensional effective action. The equations of motion admit string like solutions. The symmetry properties of the four…
Exact solutions of heterotic string theory corresponding to four-dimensional magnetic black holes in $N=4$ supergravity are described. The solutions describe the black holes in the throat limit, and consist of a tensor product of an $SU(2)$…
We present a class of exact solutions for homogeneous, anisotropic cosmologies in four dimensions derived from the low-energy string effective action including a homogeneous dilaton $\phi$ and antisymmetric tensor potential $B_{\mu\nu}$.…
We study configurations consisting of a pair of non-extremal black holes in four dimensions, both with the same mass, and with charges of the same magnitude but opposite sign---diholes, for short. We present such exact solutions for…
We study classical closed bosonic strings probing the near-horizon region of a non-extremal black hole and show that this corresponds to understanding string theory in the Carroll regime. This is done by first performing a Carroll expansion…
I review several aspects of torsion in string-inspired cosmologies. In particular, I discuss its connection with fundamental, string-model independent, axion fields associated with the massless gravitational multiplet of the string. I argue…
The absorption of photons and fermions into four-dimensional black holes is described by equations which in certain cases can be analyzed using dyadic index techniques. The resulting absorption cross-sections for near-extremal black holes…
We present a new set of analytic solutions of general relativity with a negative cosmological constant, which describe black strings and black p-branes in arbitrary number of dimensions, $D$. The solutions are supported by minimally…
A full quantum description of global vortex strings is presented in the framework of a pure Higgs system with a broken global U(1) symmetry in 3+1D. An explicit expression for the string creation operator is obtained, both in terms of the…
We present arguments for the existence of new black string solutions with negative cosmological constant. These higher-dimensional configurations have no dependence on the `compact' extra dimension, and their conformal infinity is the…