All talks are in Smith 204, Rutgers-Newark.

2pm, Wednesday March 22, 2000
Algebra and Number Theory Seminar:
Speaker: Razan Obaisi, Rutgers-Newark
Title: Eisenstein cocycle for GL_2 over immaginary quadratic fields (2)

4:15pm, Wednesday March 22, 2000
Poincare Seminar:
Speaker: Chengwen Wang, Rutgers-Newark
Title: Multiple Periodic Solutions for Non-autonomous Asymptotically Linear Hamiltonian Systems
Abstract: In this paper, we study the multiplicity of periodic solutions for the following asymptotically linear Hamiltonian system: $$ J \. x+H'(t,x)=0, $$ where $H:( [0, T] \times {\bf R} ^{2N} \to {\bf R})$ is continuous with $H(t, \cdot )$ convex and differentiable on ${\bf R}^{2N}$ for each $t \in {\bf R}$, $H( \cdot, u)$ being $T-$ periodic for each $ u \in {\bf R}^{2N}$, and $H'(t,u)$ continuous. By applying Morse theory, a lower bound for the number of periodic solutions, which depends on the Morse indices for the corresponding linear systems at the origin and infinity, is given and a new formula for the Morse index for linear Hamiltonian systems is derived.