Theta-Induced Diffusion on Tate Elliptic Curves over Non-Archimedean Local Fields
Patrick Erik Bradley
TL;DR
This work develops diffusion operators on Tate elliptic curves over non-archimedean local fields, constructing an $L^2$-type operator $\mathcal{H}_\theta$ from a theta-function kernel using the invariant measure $|\omega|$ and proving a Berkovich-analytic analogue. The spectrum of the diffusion is purely discrete, comprising a finite part from a $v(q)$-dimensional circle-structure and an infinite Kozyrev-wavelet part, and a corresponding heat equation yields a Markov process on the rational points. Extending to the Berkovich space via the Monge-Ampère equation and Chambert-Loir measures, the diffusion $\mathcal{H}_{\theta,\sigma}$ retains the same spectrum and induces a diffusion on $E_q^{an}$. Importantly, spectral data encode arithmetic features of the Tate curve, such as 2-torsion and the parity of $v(q)$, establishing a bridge between ultrametric diffusion and Tate-curve arithmetic with potential applications ranging from geometric reconstruction to data analysis in topological settings.
Abstract
A diffusion operator on the $K$-rational points of a Tate elliptic curve $E_q$ is constructed, where $K$ is a non-archimedean local field, as well as an operator on the Berkovich-analytification $E_q^{an}$ of $E_q$. These are integral operators for measures coming from a regular $1$-form, and kernel functions constructed via theta functions. The second operator can be described via certain non-archimedan curvature forms on $E_q^{an}$. The spectra of these self-adjoint bounded operators on the Hilbert spaces of $L^2$-functions are identical and found to consist of finitely many eigenvalues. A study of the corresponding heat equations yields a positive answer to the Cauchy problem, and induced Markov processes on the curve. Finally, some geometric information about the $K$-rational points of $E_q$ is retrieved from the spectrum.
