Neil Dummigan
Title: A U(2,2) analogue of Harder's conjecture.
I will review a conjecture of Harder on congruences between
Hecke eigenvalues of classical cusp forms and Siegel
cusp forms of genus 2, modulo primes appearing
in critical values of the Hecke L-function. Then I will
describe an analogue involving symmetric square L-values
of forms with imaginary quadratic character, and
automorphic representations of the group U(2,2).