题 目: From S^1-gerbes over [G/G]to affine deformations of cotangent groupoids
主讲人: 戚铠川
单 位: 宾夕法尼亚州立大学
时 间: 2026年5月23日 15:00
地 点: 鱼虾蟹游戏
一楼报告厅
摘 要: For a compact connected Lie group G, I willexplain how the Kac-Moody S^1-central extension ofLG gives an explicit S^1-gerbe over the quotient stack[G/G], whose Dixmier-Douady class is the Alekseev-Malkin-Meinrenken class. I will then describe a generalmechanism suggested by this example: an S^1-centralextension of Lie groupoids, via nonzero symplecticreduction of cotangent groupoids, produces an affinedeformation of $TA*\mathcal {G rightrightarrowsA^*$. This is joint work with Dadi Ni.
