Overconvergent modular form

Overconvergent modular forms are a special class of modular forms that arise in the context of p-adic analysis and arithmetic geometry, particularly in relation to the theory of p-adic modular forms and overconvergent systems of forms. In classical terms, a modular form is a complex analytic function on the upper half-plane that satisfies specific transformation properties under the action of a congruence subgroup of \( SL(2, \mathbb{Z}) \).