Yamanouchi topplings (or firings)

Thời gian: 09:30 đến 11:30 Ngày 27/10/2016

Địa điểm: C2-714

Tóm tắt:

I will present recent results obtained by P. Petrullo and D. Senato  with which  I gave some little  contribution.
We presented a new constraint in the chip firing game,  namely a toppling of vertex $i$ is allowed only if has toppled a  less number of times than the vertices  1, 2, \ldots,  $i-1$. So that the word expressing the sequence of toppllings is what is often called a Yamanouchi word. To study this situation we introduce some generators for the toppling group. With these generators an element of the group may have 1 or many decompositions as a product of them. The enumeration of the number of decompositions gives rise to polynomials and Laurent series related to the Hall-Littlewood function.