HOẠT ĐỘNG TRONG TUẦN

Hurwitz trees and abelian coverings
Báo cáo viên: Đặng Quốc Huy

Thời gian: 9h Thứ 4 ngày 4/11/2020

Địa điểm: Phòng 612, Nhà A6, Viện Toán học, 18 Hoàng Quốc Việt, Cầu Giấy, Hà Nội

Tóm tắt: In this talk, we introduce the Hurwitz tree's notion for abelian coverings of a rigid disc. It is a combinatorial-differential object endowed with the cover's essential degeneration data measured by (Kazuya) Kato's refined Swan conductor. We then discuss how to use these trees to study the moduli space that parametrizes Galois covers and their invariants (e.g., p-rank, a-number, Newton polygon). For instance, the technique was used to show that the moduli space of Artin-Schreier covers (Z/p-covers of the projective line in characteristic p) of fixed genus g is connected when g is large.

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