English

Eisenstein series, $p$-adic modular functions, and overconvergence, II

Number Theory 2023-12-15 v1

Abstract

Let pp be a prime number. Continuing and extending our previous paper with the same title, we prove explicit rates of overconvergence for modular functions of the form EkV(Ek)\frac{E_k^{\ast}}{V(E_k^{\ast})} where EkE_k^{\ast} is a classical, normalized Eisenstein series on Γ0(p)\Gamma_0(p) and VV the pp-adic Frobenius operator. In particular, we extend our previous paper to the primes 22 and 33. For these primes our main theorem improves somewhat upon earlier results by Emerton, Buzzard and Kilford, and Roe. We include a detailed discussion of those earlier results as seen from our perspective. We also give some improvements to our earlier paper for primes p5p\ge 5. Apart from establishing these improvements, our main purpose here is also to show that all of these results can be obtained by a uniform method, i.e., a method where the main points in the argumentation is the same for all primes. We illustrate the results by some numerical examples.

Keywords

Cite

@article{arxiv.2302.02630,
  title  = {Eisenstein series, $p$-adic modular functions, and overconvergence, II},
  author = {Ian Kiming and Nadim Rustom},
  journal= {arXiv preprint arXiv:2302.02630},
  year   = {2023}
}
R2 v1 2026-06-28T08:32:44.998Z