Algebra and Number Theory Day: Laura DeMarco (Harvard)

Gilman Hall 132

Title: From Manin–Mumford to Dynamical Rigidity.Abstract:  In the early 1980s, Raynaud proved a theorem (the Manin–Mumford Conjecture) about the geometry of torsion points in abelian varieties, using number-theoretic methods.  Around the same time, and with completely different methods, McMullen proved a dynamical rigidity theorem for holomorphic maps on P1.  In recent work, joint with Myrto […]

Algebra and Number Theory Day: Alexander Petrov (MIT)

Gilman Hall 132

Title: Characteristic classes of p-adic local systems.Abstract: A useful tool in studying vector bundles on topological spaces or algebraic varieties is characteristic classes in cohomology, such as Chern classes. For vector bundles equipped with a flat connection, Chern classes vanish in cohomology with rational coefficients, but such bundles have a non-trivial theory of secondary characteristic classes, […]

Algebra and Number Theory Day: Mihnea Popa (Harvard)

Gilman Hall 132

Title: Hodge symmetries of singular varieties.Abstract: The Hodge diamond of a smooth projective complex variety contains essential topological and analytic information, including fundamental symmetries provided by Poincaré and Serre duality. I will describe recent progress on understanding how much symmetry there is in the analogous Hodge–Du Bois diamond of a singular variety, and the concrete ways […]

Number Theory Seminar: Carl Wang-Erickson (University of Pittsburgh)

Krieger 411

Title: Bi-ordinary modular forms Abstract: Hida theory provides a p-adic interpolation of modular forms that have an ordinary property. Correspondingly, the p-adic 2-dimensional Galois representations associated to the eigensystems of the Hecke action on these ordinary modular forms have a property known as ordinary: when restricted to a decomposition group at p, this representation is […]