A Generalized Jacobi Theta Function and Quasimodular Forms
A Generalized Jacobi Theta Function and Quasimodular Forms
复制标题
DOI:
10.1007/978-1-4612-4264-2_6
复制
发表时间:
1995
影响因子:
1.2
通讯作者:
M. Kaneko;D. Zagier
中科院分区:
文献类型:
--
作者:
M. Kaneko;D. Zagier
In this note we give a direct proof using the theory of modular forms of a beautiful fact explained in the preceding paper by Robbert Dijkgraaf [1, Theorem 2 and Corollary]. Let M.(r1) denote the graded ring of quasi-modular forms on the full modular group r1= PSL (2, Z). This is the ring generated by G2, G4, G6, and graded by assigning to each Gk the weight k, where (k~ 2, Bk= kth Bernoulli number) are the classical Eisenstein series, all of which except G2 are modular.(See § 1 for a more general and more intrinsic definition of quasi-modular.) We define a generalization of the classical Jacobi theta function by the triple product