Geometria Spin structures on tropical hyperelliptic graphs and the Z_2-quadratic form Alessandro Chiodo 04-11-2021 - 14:15 Largo San Leonardo Murialdo, 1
We present briefly the theory of divisors on graphs, parallel to that ofline bundles on curves. We show some tools for computing the ranks of spin structures. In general the rank singles out a distinguished noneffective spin structure, but the parity of the rank is not a quadratic form. In the case of hyperelliptic spin structures the parity is a Z/2-quadratic form. We take this as an opportunity to detail the interplay between combinatorial and algebraic rank over the moduli space. |