Modular form

In mathematics, a modular form is a (complex) analytic function on the upper half-plane satisfying a certain kind of functional equation with respect to the group action of the modular group, and also satisfying a growth condition.

Quotes

• Modular forms have long played a key role in the theory of numbers, including most famously the proof of Fermat's Last Theorem.
  • Noriko Yui, Helena Verrill, and Charles F. Doran. Modular Forms and String Duality. American Mathematical Society. p. 9. ISBN 978-0-8218-7157-7.