325 citations · 952 across the 30 of their papers we have counts for
10 papers · 1 filter
Generating Generalized solutions
N. Bretón, A. Feinstein, L. A. López +1
We show how one can systematically construct vacuum solutions to Einstein field equations with commuting Killing vectors in dimensions. The construction uses Einstein-s…
Ghosts in a Mirror
Alexander Feinstein, Sanjay Jhingan
We look at some dynamic geometries produced by scalar fields with both the "right" and the "wrong" sign of the kinetic energy. We start with anisotropic homogeneous universes with…
Penrose Limits, the Colliding Plane Wave Problem and the Classical String Backgrounds
Alexander Feinstein
We show how the Szekeres form of the line element is naturally adapted to study Penrose limits in classical string backgrounds. Relating the "old" colliding wave problem to the Pen…
Power-Law Inflation from the Rolling Tachyon
Alexander Feinstein
Modeling the potential by an inverse square law in terms of the tachyon field () we find exact solution for spatially flat isotropic universe.We show that for $β>2\sq…
Curved dilatonic brane worlds
A. Feinstein, K. E. Kunze, M. A. Vazquez-Mozo
We construct a broad family of exact solutions to the five-dimensional Einstein equations coupled to a scalar field with an exponential potential. Embedding a three-brane in these…
Entropy generation and inflation in wave collision induced pre-big-bang cosmology
A. Feinstein, K. E. Kunze, M. A. Vazquez-Mozo
We study inflation and entropy generation in a recently proposed pre-big-bang model universe produced in a collision of gravitational and dilaton waves. It is shown that enough inf…
Initial Conditions and the Structure of the Singularity in Pre-Big-Bang Cosmology
A. Feinstein, K. E. Kunze, M. A. Vazquez-Mozo
We propose a picture, within the pre-big-bang approach, in which the universe emerges from a bath of plane gravitational and dilatonic waves. The waves interact gravitationally bre…
M-theory resolution of four-dimensional cosmological singularities via U-duality
A. Feinstein, M. A. Vazquez-Mozo
We consider cosmological solutions of string and M-theory compactified to four dimensions by giving a general prescription to construct four-dimensional modular cosmologies with tw…
Can the Type-IIB axion prevent Pre-big Bang inflation?
A. Feinstein, M. A. Vazquez-Mozo
We look at the possibility of superinflationary behavior in a class of anisotropic Type-IIB superstring cosmologies in the context of Pre-big Bang scenario and find that there exis…
Closed Inhomogeneous String Cosmologies
A. Feinstein, Ruth Lazkoz, M. A. Vazquez-Mozo
We present a general algorithm which permits to construct solutions in string cosmology for heterotic and type-IIB superstrings in four dimensions. Using a chain of transformations…