Date and Time: Wednesday, 17th February 2021 at 2 PM
Google Meet Link: https://meet.google.com/zif-jpge-ybc?hs=122&authuser=1
Speaker: Sagar Kalane, IISER Pune
Title: Classification of pairs of quaternionic and complex hyperbolic
isometries
Abstract:
Consider the Lie groups G=SU(n, 1) and Sp(n, 1) that act as isometries
of the complex and the quaternionic hyperbolic spaces respectively. In
this talk, we will classify pairs of semisimple elements in Sp(n, 1) and
SU(n, 1) up to conjugacy. This gives local parametrization of the
representations ρ in deformation space Hom(F2, G)/G such that both
ρ(x) and ρ(y) are semisimple elements in G, where F2 = , G =
Sp(n, 1) or SU(n, 1). Also, we shall classify conjugation orbits of
non-singular pairs of loxodromic elements in SU(n,1). This is a survey
of joint work with Krishnendu Gongopadhyay
Time:
6:30pm
Description:
Speaker:* Bernd Ulrich, Purdue University, West Lafayette, IN, USA*
Date/Time: *19 February 2021, 6:30pm IST/ 1:00pm GMT/ 8:00am EST* (joining
time: 6:15 pm IST - 6:30 pm IST)
Google meet link: https://meet.google.com/kav-pjey-rir
Title:* Generalized multiplicities and integral dependence*
Abstract: The talks will give a survey about multiplicity based criteria
for the integral dependence of ideals. This subject has close connections
with equisingularity theory and intersection theory, which will be
discussed as well. The first numerical criterion for integral dependence
was proved in the 1960s by Rees who treated the case of zero-dimensional
ideals using the Hilbert-Samuel multiplicity. Criteria for arbitrary
ideals require generalized notions of multiplicities. We will discuss
various such
notions and talk about how they are used to detect integral dependence. The
most recent results are from joint work with Claudia Polini, Ngo Viet
Trung, and Javid Validashti.
For more information and links to previous seminars, visit the website of
VCAS: https://sites.google.com/view/virtual-comm-algebra-seminar.