APS
Speaker: Imran Hussain (IIT Bombay)
Host: Saikat Mazumdar
Title: Rigidity results for the Q curvature equation on Einstein manifolds
Time, day and date: 11:30:00 AM – 12:30:00 PM, Monday, September 15
Venue: Ramanujan Hall
Abstract: In this seminar, we classify the constant Q-curvature conformal metrics(cQcc metrics) on Einstein manifolds. We show that on Einstein manifolds cQcc metrics are rigid in the sense that if (M,g) is Einstein then cQcc metrics in the conformal class of g are all of the form "a times g" where "a" is constant

Seminar
Speaker: Prof. Sanghoon Kwon (Catholic Kwandong University, Republic of Korea)
Host: Dipendra Prasad
Title: Non-uniform quotient of Bruhat-Tits buildings: spectral geometry and representation theory
Time, day and date: 2:30:00 PM, Monday, September 15
Venue: Room 105
Abstract: In this talk, we explore the rich interplay between the geometry of Bruhat–Tits buildings and the spectral theory of their non-uniform arithmetic quotients over global function fields. Beginning with an introduction to the Bruhat–Tits tree for PGL2 and higher dimensional buildings for groups, we investigate how these combinatorial and geometric objects give rise to Ramanujan complexes through the theory of automorphic representations.
We emphasize non-uniform lattices arising from function fields, highlighting how Eisenstein series and the residual spectrum contribute to the spectral decomposition. Special attention will be paid to the structure of the Laplacian spectrum on these quotients and the role of the Hecke operators. No special background is assumed. Part of this presentation is based on the joint work with Soonki Hong.