The weighted projective Serre bound conjecture

Let qq be a prime power, let a0,ots,ana_0,ots,a_n be positive weights, and let eq(d;a0,a1,ots,an)e_q(d;a_0,a_1,ots,a_n) be the maximum number of Fq{\mathbb F}_q-rational points on a hypersurface of weighted degree dd in P(a0,ots,an){\mathbb P}(a_0,ots,a_n). Let pn=qn+ots+q+1p_n=q^n+ots+q+1 for n0n\geq 0 and pn=0p_n=0 for n<0n<0. The weighted projective Serre bound conjecture. If a0=1a_0=1, lcm(a1,a2,ots,an)d\operatorname{lcm}(a_1,a_2,ots,a_n)\mid d, and a1a2\leqotsana_1\leq a_2\leqots\leq a_n, then

eq(d;1,a1,a2,ots,an)=min{pn,da1qn1+pn2}.e_q(d;1,a_1,a_2,ots,a_n)=\min\left\{p_n,\frac{d}{a_1}q^{n-1}+p_{n-2}\right\}.

The conjecture generalizes the Serre bound from ordinary projective spaces to weighted projective spaces. The paper proves it in every dimension when the second weight is also one, so the general case remains open.

Sources & referencesView supporting material

Primary source

Yves Aubry and Marc Perret, “Maximum number of rational points on hypersurfaces in weighted projective spaces over finite fields”, arXiv:2402.07522 (2025).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.