# Fungrim entry: 27c319

$\theta_4\!\left(z, \tau\right) = \sum_{n=-\infty}^{\infty} {\left(-1\right)}^{n} {e}^{\pi i \left({n}^{2} \tau + 2 n z\right)}$
Assumptions:$z \in \mathbb{C} \,\mathbin{\operatorname{and}}\, \tau \in \mathbb{H}$
TeX:
\theta_4\!\left(z, \tau\right) = \sum_{n=-\infty}^{\infty} {\left(-1\right)}^{n} {e}^{\pi i \left({n}^{2} \tau + 2 n z\right)}

z \in \mathbb{C} \,\mathbin{\operatorname{and}}\, \tau \in \mathbb{H}
Definitions:
Fungrim symbol Notation Short description
JacobiTheta4$\theta_4\!\left(z, \tau\right)$ Jacobi theta function
Pow${a}^{b}$ Power
Exp${e}^{z}$ Exponential function
ConstPi$\pi$ The constant pi (3.14...)
ConstI$i$ Imaginary unit
Infinity$\infty$ Positive infinity
CC$\mathbb{C}$ Complex numbers
HH$\mathbb{H}$ Upper complex half-plane
Source code for this entry:
Entry(ID("27c319"),
Formula(Equal(JacobiTheta4(z, tau), Sum(Mul(Pow(-1, n), Exp(Mul(Mul(ConstPi, ConstI), Add(Mul(Pow(n, 2), tau), Mul(Mul(2, n), z))))), Tuple(n, Neg(Infinity), Infinity)))),
Variables(z, tau),
Assumptions(And(Element(z, CC), Element(tau, HH))))

## Topics using this entry

Copyright (C) Fredrik Johansson and contributors. Fungrim is provided under the MIT license. The source code is on GitHub.

2019-06-18 07:49:59.356594 UTC