English

Analogies of Jacobi's formula

Classical Analysis and ODEs 2022-03-16 v1 Algebraic Geometry

Abstract

By considering Schwarz's map for the hypergeometric differential equation with parameters (a,b,c)=(1/6,1/2,1)(a,b,c)=(1/6,1/2,1) or (1/12,5/12,1)(1/12,5/12,1), we give some analogies of Jacobi's formula ϑ00(τ)2=F(1/2,1/2,1;λ(τ))\vartheta_{00}(\tau)^2= F(1/2,1/2,1;\lambda(\tau)), where ϑ00(τ)\vartheta_{00}(\tau) and λ(τ)\lambda(\tau) are the theta constant and the lambda function defined on the upper-half plane, and F(a,b,c;z)F(a,b,c;z) is the hypergeometric series defined on the unit disk. As applications of our formulas, we give several functional equations for F(a,b,c;z)F(a,b,c;z).

Keywords

Cite

@article{arxiv.2203.07617,
  title  = {Analogies of Jacobi's formula},
  author = {Keiji Matsumoto},
  journal= {arXiv preprint arXiv:2203.07617},
  year   = {2022}
}

Comments

26 pages, 3 figures