Time: 9:00 - 10:00 (VN time), 11:00-12:00 (Japan time) 16th February

Venue: Room 507, A6, Institute of Mathematics

Online (Zoom):

https://us06web.zoom.us/j/82191500949?pwd=UVlmYXFOMGFrQS9FY3Nja1labWRmZz09

Meeting ID: 821 9150 0949

Passcode: 123456

Abstract: It is a central question in the topology of hyperplane arrangements whether several topological invariants are combinatorially determined, for example, the rank of twisted cohomology groups of the complement, and the torsions in the homology of Milnor fibers or covering spaces. In this talk, we give a formula on the 2-torsion of double coverings, which refines the formula conjectured by Papadima-Suciu. We also discuss the recent study on integral local system cohomology groups of arrangements. This is partially joint work with Suguru Ishibashi (Arise analytics, inc.) and Masahiko Yoshinaga (Osaka University)