386 citations · 7.3k across the 146 of their papers we have counts for
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Hyperbolic Space Cosmologies
Chiang-Mei Chen, Pei-Ming Ho, Ishwaree P. Neupane +2
We present a systematic study of accelerating cosmologies obtained from M/string theory compactifications of hyperbolic spaces with time-varying volume. A set of vacuum solutions w…
Intersecting branes in pp-wave spacetime
Nobuyoshi Ohta, Kamal L. Panigrahi, Sanjay
We derive intersecting brane solutions in pp-wave spacetime by solving the supergravity field equations explicitly. The general intersection rules are presented. We also generalize…
Uniqueness of M-theory PP-Wave Background with Extra Supersymmetries
Nobuyoshi Ohta, Makoto Sakaguchi
We examine Killing spinor equations of the general eleven-dimensional pp-wave backgrounds, which contain a scalar H(x^m,x^-) in the metric and a three-form ξ(x^m,x^-) in the flux.…
A Study of Accelerating Cosmologies from Superstring/M theories
Nobuyoshi Ohta
We study aspects of the accelerating cosmologies obtained from the compactification of vacuum solution and S2-branes of superstring/M theories. Parameter dependence of the resultin…
Accelerating Cosmologies from S-Branes
Nobuyoshi Ohta
We point out that the recently proposed model of a flat 4-dimensional universe with accelerated expansion in string/M-theory is a special case of time-dependent solutions that the…
Null-Brane Solutions in Supergravities
Nobuyoshi Ohta
We find a new class of time-dependent brane solutions in supergravities in arbitrary dimensions . These are general intersecting light-like branes (null-branes), and their super…