The Algebra Seminar on Friday 8 April will be given by Ruibin Zhang. I will be overseas from 2 April until 7 May. While I am away, Anthony Henderson will host the seminar and lunch, and Andrew Mathas will be in charge of the webpage and announcements. Thank you to Anthony and Andrew for filling in. --------------------------------------------------------------------- Speaker: Ruibin Zhang (University of Sydney) Date: Friday 8 April Time: 12.05-12.55pm Venue: Carslaw 175 Title: Jantzen filtration for Kac modules Abstract: A Jantzen type filtration is introduced for generalised Varma modules over Lie superalgebras. In the case of type I Lie superalgebras, we show that the generalized Jantzen filtration for any Kac module is the unique Loewy filtration, and the decomposition numbers of the layers of the filtration are determined by the coefficients of inverse Kazhdan-Lusztig polynomials. Furthermore, the length of the Jantzen filtration for any Kac module is equal to the degree of atypicality. These results led to a detailed description of the submodule lattices of Kac modules. This is joint work with Yucai Su. ---------------------------------------------------------------------