# December, 2011

## Frozen Gaussian approximation for high frequency wave propagation

Seminar/Colloquium/Special TalkTalk Series:Special TalkSpeaker:Xu Yang (Courant Institute)Place :511 Lake Hall, Northeastern UniversityDate:Thursday, December 1, 2011 - 4:30pm - 5:30pm## Moduli Space of Marked Cubic Surfaces

Seminar/Colloquium/Special TalkTalk Series:Speaker:Laurent Gruson (University of Versailles)Place :511 Lake Hall, Northeastern UniversityDate:Friday, December 2, 2011 - 10:00am - 11:00am(Notice unusual time)Abstract: I will first explain what marked cubic surfaces are and the action of the Weyl group of the root system E6 on their moduli space. Then I will describle an equivariant rational map from this moduli space to the projectivised complexified root lattice.## Finite-Dimensional Representations of osp(2n+1,2n) in Small Rank

Seminar/Colloquium/Special TalkTalk Series:Speaker:Caroline Gruson (University of Nancy)Place :511 Lake Hall, Northeastern UniversityDate:Friday, December 2, 2011 - 11:00am - 12:00pm(Notice unusual time)Abstract: I will explain algorithms computing the character of a simple module and composition series of indecomposable projective modules.## Delta-modules and syzygies of Segre embeddings

Seminar/Colloquium/Special TalkTalk Series:Special TalkSpeaker:Andrew Snowden (MIT)Place :544 Nightingale Hall, Northeastern UniversityDate:Friday, December 2, 2011 - 3:00pm - 4:00pm## Equivariant Analogues of the Ham Sandwich Theorem

Seminar/Colloquium/Special TalkSpeaker:Steve Simon, Courant Institute and Cooper UnionPlace :511 Lake HallDate:Monday, December 5, 2011 - 12:15pm - 1:15pmThe Ham Sandwich Theorem states that under generic conditions any n finite Borel measures on R^n can be bisected by a single hyperplane. Viewing this theorem as a Z_2-symmetry statement for measures, we generalize the theorem to other finite groups, notably the finite subgroups of the spheres S^1 and S^3, in each case realizing group symmetries on Euclidian space as group symmetries of its Borel measures by studying the topology of associated spherical space forms. Direct equipartition statements for measures are given as special cases. We shall also discuss the contributions of the tangent bundles of these manifolds in answering similar questions.