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Naoyuki Koike

Associate Professor in
Differential Geometry


Members of Koike laboratory study Differential Geometry which closely related to Einstein's General Relativity.
Mainly we study Submanifold Theory in Symmetric Spaces.

Main two methods of the research are as follows:
1. Research of submanifolds in symmetric       spaces of compact type
   〜 by reducing research of submani-
     folds in an infinite dimensional
     linear space obtained by canceling
     holonom of the symmetric space〜
We reasearch submanifolds in a symmetric space
of compact type by reducing to reasearch of sub-
manifolds in an infinite dimensional Hilbert space
through a Riemannian submersion of the Hilbert
space onto the symmetric space. This reducement
of research is valid because symmetric spaces of compact type has holonom but the Hilbert space
has no holonom.

2. Research of submanifolds in symmetric
  spaces of noncompact type
  〜 by reducing to research of submani-
    folds in an infinite dimensional
    complex linear space obtained by
    canceling holonom of the complexi-
    fication of the symmetric space〜
We reasearch submanifolds in a symmetric space
of compact type by reducing to reasearch of sub-
manifolds in an infinite dimensional anti-Kaehlerian
space through a Riemannian submersion of the anti-Kaehlerian space onto the complexification
of the symmetric space. This reducement of research
is valid in the following two aspects:
(1) A symmetric space of noncompact type has
holonom but the infinite dimensional anti-Kaehlerian
space has no holonom.
(2) Some geometrical structures (of the submanifold) vanishing beyond the ideal boundary of a symmetric
space of non-compact type appear in the complexified space.

Please click here to see a survey of my
recent research for a proper complex
equifocal submanifold.
(Update : January 17, 2011)