# 組合せ論セミナー

## 第31回 2012年12月4日 14:30〜16:00

中島規博（北海道大学）「A canonical system of basic invariants」

It is known that the invariant ring of a finite reflection group is generated by algebraically independent homogeneous polynomials. A system of such generators is called a system of basic invariants. Flatto and Wiener verified that there exists a canonical system of basic invariants (formulated by Iwasaki) for any finite reflection group. Iwasaki and some researchers gave explicit formulas of canonical systems for irreducible finite reflection groups ecxept type E. In this talk, we uniformly determine canonical systems by using arbitrary system of basic invariants. This work is based on a joint work with Shuhei Tsujie.