A new edition of a classical treatment of elliptic and modular functions with some of their number-theoretic applications, this text offers an updated bibliography and an alternative treatment of the transformation formula for the Dedekind eta function. It covers many topics, such as Hecke’s theory of entire forms with multiplicative Fourier coefficients, and the last chapter recounts Bohr’s theory of equivalence of general Dirichlet series.
My first book ever to read when I studied the theory of modular forms. A very nice and easy approach to the theory that allows one to really like modular forms and get the feel of why the theory is important from a number-theoretic point of view.