Yasuhide Numata : On a bijective proof of a factorization formula for Macdonald polynomials at roots of unity

The subject of this talk is a factorization formula for the special values of modied Macdonald polynomials at roots of unity. We give a combinatorial proof of the formula, via a result by Haglund-Haiman-Leohr, for some special classes of partitions, including two column partitions. (This talk is based on a joint work with F. Descouens and H. Morita.)