Moments of zeta functions associated to hyperelliptic curves

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Michael Rubinstein , University of Waterloo

I will discuss conjectures, theorems, and experiments concerning the moments, at the central point, of zeta functions associated to hyperelliptic curves over finite fields of odd characteristic. Let q be an odd prime power, and Hd,q denote the set of square-free monic polynomials D(x)Fq[x] of degree d. Let 2g=d1 if d is odd, and 2g=d2 if d is even. Katz and Sarnak showed that the moments (over Hd,q) of the zeta functions associated to the curves y2=D(x), evaluated at the central point, tend, as q, to the moments of characteristic polynomials of matrices in USp(2g), evaluated at the central point. Using techniques that were originally developed for studying moments of L-functions over number fields, Andrade and Keating have conjectured an asymptotic formula for the moments for q fixed and d. We provide theoretical and numerical evidence in favour of their conjecture. We will also discuss uniform estimates, in both parameters q,d, for the moments. This is joint work with Kevin Wu.