Affiliaton: Department of Mathematics Kyoto University
Position: Associate Professor
Research field: Geometric representation theory
Degree: Dr. (Math. Sci.) University of Tokyo 2003
	Advisor: Hisayosi Matumoto
	Dissertation: Equivariant bundles on group completions
Postal Address: Oiwake Kita-Shirakawa Sakyo Kyoto 606-8502 JAPAN
	Department of Mathematics, Kyoto University
E-mail:

Some papers:

1. A Borel-Weil-Bott type theorem for group completions
   • Published in the Journal of Algebra 259 no.2 572--580 (2003) Article
   • I computed the total cohomology of an arbitrary line bundle of the De-Concini-Procesi compactification of an adjoint semi-simple group over complex numbers.
   • The same result was obtained independently by Alexis Thoudjem. He subsequently extended this result in several directions. See [Comptes Rendes 334 2002][Ann. Sci. ENS (4) 37 2004][Bull. Soc. Math. Fr. 135 2007]
2. Equivariant vector bundles on group completions
   • Published in the Journal f\"ur die reine und angewandte Mathematik 581 71--116 (2005) Article arXiv
   • I described the category of bi-equivariant vector bundles of an arbitrary (bi-equivariant) toroidal compactification of a reductive group over complex numbers.
   • This is (a revised form of) my thesis.
3. An exotic Deligne-Langlands correspondence for symplectic groups
   • Published in the Duke Mathematical Journal 148 no.2 305--371 (2009) Article arXiv errata
   • I gave a variant of the Lusztig formalism of the Deligne-Langlands conjecture (for Hecke algebras), which exist only for symplectic group. As a consequence, I completed the classification of simple modules of affine Hecke algebras of classical types, except for the case roughly corresponding to "small root-of-unity parameter" case.
4. Deformations of nilpotent cones and Springer correspondences
   • Published in the American Journal of Mathematics 133 no.2 519--553 (2011) Article ArXiv
   • I determined our variant of Springer representations (introduced in [3]), and compared with the ordinary one. This gives computations of Joseph polonomials (up to scalar) in many cases which are previously unknown.
   • Dedicated to Ken-ichi Shinoda and Toshiaki Shoji on the occasion of their 60th birthdays
5. Tempered modules in exotic Deligne-Langlands correspondences
   • Published in the Advances in Mathematics 226 no.2 1538--1590 (2011) Article ArXiv
   • We determined the parameters corresponding to tempered modules within the framework of [3]. As a bonus, we completed the Heckman-Opdam theory on the classification of square-integrable solutions of an integrable system, called the Lieb-McGuire system.
   • This is a joint work with Dan Ciubotaru.
6. Tensor products and Minkowski sums of Mirkovic-Vilonen polytopes
   • 12pp, to appear in the Transformation groups arXiv
   • We proved that the tensor product of two MV polytopes (moment map image of a geometric realization of B(\lambda)) is contained in their natual sum as convex polytopes.
   • This is a joint work with Satoshi Naito and Daisuke Sagaki, but my contribution is "epsilon"
7. A homological study of Green polynomials
   • 41pp, arXiv, to appear in the Annales Scientifiques de l'Ecole Normale Superieure.
   • We interpreted the orthogonality relation of Green functions (which are functions roughly govern the characters of finite groups of Lie types) in terms of homological algebra. In particular, we gave a new characterization of Green polynomials. Using this, we derived several properties of Green polynomials of type BC, including a transition formula along a parameter. The concept of Kostka systems (which is an abstraction of the above characterization) and its basic properties is designed to be applicable for complex reflection groups.

Other papers can be found here.

Last update: September 23, 2014 by