93 citations · 620 across the 26 of their papers we have counts for
26 papers
Geometric deformations of symmetric spacetimes with a string cloud
Hiroshi Kozaki, Satsuki Matsuno, Tatsuhiko Koike +2
We establish a deformation framework for highly symmetric solutions to the Einstein equations. In this framework, four-dimensional metrics are constructed from three-dimensional η-…
Spacetime constructed from a contact manifold with a degenerate metric
Hiroshi Kozaki, Hideki Ishihara, Tatsuhiko Koike +1
We construct a four-dimensional spacetime using a three-dimensional contact manifold equipped with a degenerate metric. The degenerate metric is set to be compatible with the conta…
Nambu-Goto Strings with a null symmetry and contact structure
Hiroshi Kozaki, Tatsuhiko Koike, Yoshiyuki Morisawa +1
We study the classical dynamics of the Nambu-Goto strings with a null symmetry in curved spacetimes admitting a null Killing vector field. The Nambu-Goto equation is reduced to fir…
Cohomogeneity-one-string integrability of spacetimes
Yoshiyuki Morisawa, Soichi Hasegawa, Tatsuhiko Koike +1
We present a framework for reducing all possible cohomogeneity-one strings, i.e., strings with geometrical symmetry, in a given spacetime to mechanical systems, and for analyzing i…
Antisymmetric tensor generalizations of affine vector fields
Tsuyoshi Houri, Yoshiyuki Morisawa, Kentaro Tomoda
Tensor generalizations of affine vector fields called symmetric and antisymmetric affine tensor fields are discussed as symmetry of spacetimes. We review the properties of the symm…
Relativistic Gravitational Collapse of a Cylindrical Shell of Dust II: Settling Down Boundary Condition
Ken-ichi Nakao, Tomohiro Harada, Yasunari Kurita +1
We numerically study the dynamics of an imploding hollow cylinder composed of dust. Since there is no cylindrical black hole in 4-dimensional spacetime with physically reasonable e…