20 citations · 22 across the 2 of their papers we have counts for
6 papers
Accelerating Universe via Spatial Averaging
Yasusada Nambu, Masayuki Tanimoto
We present a model of an inhomogeneous universe that leads to accelerated expansion after taking spatial averaging. The model universe is the Tolman-Bondi solution of the Einstein…
Linear perturbations of spatially locally homogeneous spacetimes
Masayuki Tanimoto
Methods and properties regarding the linear perturbations are discussed for some spatially closed (vacuum) solutions of Einstein's equation. The main focus is on two kinds of spati…
Symmetries of the Gowdy Equations and Spatial Topologies
Masayuki Tanimoto
We examine some kinds of discrete symmetries which are dynamically preserved, using the (generalized) Gowdy models of the first kind.
Averaging from a global point of view
Masayuki Tanimoto
We study the averaging problem from a point of view of variation of spatial volume . We show that in the space of spherically symmetric dust solutions which are regular on the s…
Hamiltonians for Compact Homogeneous Universes
Masayuki Tanimoto, Tatsuhiko Koike, Akio Hosoya
We briefly show how we can obtain Hamiltonians for spatially compact locally homogeneous vacuum spacetimes. The dynamical variables are categorized into the curvature parameters an…
On the null surface formalism -- Formulation in three dimensions and gauge freedom
Masayuki Tanimoto
The null surface formalism of GR in three dimensions is presented, and the gauge freedom thereof, which is not just diffeomorphism, is discussed briefly.