2 citations · 2 across the 2 of their papers we have counts for
6 papers
Conley index theory without index pairs. I: The point-set level theory
Yosuke Morita
We propose a new framework for Conley index theory. The main feature of our approach is that we do not use the notion of index pairs. We introduce, instead, the notions of compacti…
Cartan projections of some non-reductive subgroups and proper actions on homogeneous spaces
Yosuke Morita
Kobayashi [Duke Math. J. (1992)] gave a necessary condition for the existence of compact Clifford-Klein forms in terms of Cartan projections and non-compact dimensions of reductive…
Semisimple symmetric spaces that do not model any compact manifold
Yosuke Morita
In a previous paper, we obtained a cohomological obstruction to the existence of compact manifolds locally modelled on a homogeneous space. In this paper, we give a classification…
Proof of Kobayashi's rank conjecture on Clifford-Klein forms
Yosuke Morita
T. Kobayashi conjectured in the 36th Geometry Symposium in Japan (1989) that a homogeneous space G/H of reductive type does not admit a compact Clifford-Klein form if rank G - rank…
A cohomological obstruction to the existence of compact Clifford-Klein forms
Yosuke Morita
In this paper, we continue the study of the existence problem of compact Clifford-Klein forms from a cohomological point of view, which was initiated by Kobayashi-Ono and extended…
Homogeneous spaces of nonreductive type locally modelling no compact manifold
Yosuke Morita
We give necessary conditions for the existence of a compact manifold locally modelled on a given homogeneous space, which generalize some earlier results, in terms of relative Lie…