Batyrev–Manin conjecture for singular degree-one del Pezzo surfaces

Let A,BZA,B\in\mathbb{Z} satisfy 4A327B204A^3-27B^2\neq 0, let Q(u,v)Q(u,v) be a positive-definite binary quadratic form, and define

SA,B,Q:={y2=x3+AxQ(u,v)2+BQ(u,v)3}P(2,3,1,1).S_{A,B,Q}:=\{y^2=x^3+AxQ(u,v)^2+BQ(u,v)^3\}\subset\mathbb{P}(2,3,1,1).

For rational points represented by integral (x,y,u,v)(x,y,u,v) with gcd(x,u,v)=1\gcd(x,u,v)=1, use the height

h~((x,y,u,v))=max(x1/2,y1/3,u,v).\tilde{h}((x,y,u,v))=\max(|x|^{1/2},|y|^{1/3},|u|,|v|).

Let U1=P(2,3,1,1){y=0}U_1=\mathbb{P}(2,3,1,1)\setminus\{y=0\} and U2=P(2,3,1,1){Q(u,v)=0}U_2=\mathbb{P}(2,3,1,1)\setminus\{Q(u,v)=0\}, and define

N~(T):=#{(x,y,u,v)SA,B,Q(Z)U1U2:h~((x,y,u,v))T, gcd(x,u,v)=1}.\tilde{N}(T):=\#\{(x,y,u,v)\in S_{A,B,Q}(\mathbb{Z})\cap U_1\cap U_2:\tilde{h}((x,y,u,v))\leq T,\ \gcd(x,u,v)=1\}.

Assume that SA,B,Q(Q)S_{A,B,Q}(\mathbb{Q})\neq\emptyset. Batyrev–Manin conjecture. There exists a constant CA,B,QC_{A,B,Q} such that

N~(T)CA,B,QTlog(T)ϱA,B,Q1,\tilde{N}(T)\sim C_{A,B,Q}T\log(T)^{\varrho_{A,B,Q}-1},

where ϱA,B,Q\varrho_{A,B,Q} is the rank of the Picard group over Q\mathbb{Q} of the desingularization S~A,B,Q\widetilde{S}_{A,B,Q} of SA,B,QS_{A,B,Q}. This is a refinement of Manin's conjecture for these singular degree-one del Pezzo surfaces; the constant is related to Peyre's constant and need not be nonzero. Asymptotics are not known for any del Pezzo surface of degree one, although upper and lower bounds have been studied.

Sources & referencesView supporting material

Primary source

Katharine Woo, “Counting points on a family of degree one del Pezzo surfaces”, arXiv:2508.09391 (2026).

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.