Hecke indefinite modular forms

introduction

• see the appendix of
  • Michio Jimbo, Tetsuji Miwa and Masato Okado Solvable lattice models with broken  symmetry and Hecke's indefinite modular forms, 1986

history

• http://www.google.com/search?hl=en&tbs=tl:1&q=

articles

• On indefinite modular forms of weight one
  • Toyokazu HIRAMATSU, Noburo ISHII, and Yoshio MIMURA
• A new look at Hecke's indefinite theta series
  • Polishchuk, Alexander
• Solvable lattice models with broken  symmetry and Hecke's indefinite modular forms
  • Michio Jimbo, Tetsuji Miwa and Masato Okado, 1986
• Affine Lie algebras and Hecke modular forms
  • V. G. Kac and D. H. Peterson, 1980
• Über einen Zusammenhang zwischen elliptischen Modulfunktionen und indefiniten quadratischen Formen
  • E. Hecke, Mathematische Werke, Vandenhoeck and Ruprecht, Góttingen, 1959, pp. 418-427