The Cohen–Lenstra rationality conjecture for motivic curve zeta series

Let XX be a reduced curve over Fq\mathbb{F}_q, and let X~\widetilde X be its normalization. Let #q\#_q denote the point-count homomorphism from the completed Grothendieck ring to Q\mathbb{Q}. The Cohen–Lenstra rationality conjecture.

#q(Z^Xmot(t)Z^X~mot(t))Q[[t]]\#_q\left(\frac{\widehat{Z}^\mathrm{mot}_X(t)}{\widehat{Z}^\mathrm{mot}_{\widetilde X}(t)}\right)\in\mathbb{Q}[[t]]

is a power series in tt with infinite radius of convergence.

The conjecture generalizes the proved nodal case and predicts an entire point-count numerator for every reduced curve. Its cusp case is discussed as a consequence of the later cusp conjectures.

Sources & referencesView supporting material

Primary source

Yifeng Huang and Ruofan Jiang, “Punctual Quot schemes and Cohen–Lenstra series of the cusp singularity”, arXiv:2305.06411 (2023).

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.