On modular forms of dimension $-2$

Modular Forms on Sl 2 (z )

Dimension Variation of Classical and p-adic Modular Forms

A quadratic bound is obtained for a conjecture of Gouv^ ea-Mazur on arithmetic variation of dimensions of classical and p-adic modular forms.

Modular Forms on

Let k 2 Z and let SL 2 (Z) denote the special linear group SL 2 (Z) = a b c d : a; b; c; d 2 Z and ad bc = 1 : A modular form of weight k is an analytic function f de…ned on the complex upper half plane H = fz 2 C : Im(z) > 0g that transforms under the action of SL 2 (Z) according to the relation [1] f az + b cz + d = (cz + d) k f (z) for all a b c d 2 SL 2 (Z)

Slopes of overconvergent 2-adic modular forms

We explicitly compute all the slopes of the Hecke operator U2 acting on overconvergent 2-adic level 1 cusp forms of weight 0: the nth slope is 1 + 2v((3n)!/n!), where v denotes the 2-adic valuation. We formulate an explicit conjecture about what these slopes should be for weight k forms.

Estimating Siegel Modular Forms of Genus 2 Using Jacobi Forms

We give a new elementary proof of Igusa's theorem on the structure of Siegel modular forms of genus 2. The key point of the proof is the estimation of the dimension of Jacobi forms appearing in the FourierJacobi development of Siegel modular forms. This proves not only Igusa's theorem, but also gives the canonical lifting from Jacobi forms to Siegel modular forms of genus 2.