Fungrim entry: 06633e

\theta_2\!\left(z, \tau\right) = 2 \sum_{n=0}^{\infty} {e}^{\pi i {\left(n + 1 / 2\right)}^{2} \tau} \cos\!\left(\left(2 n + 1\right) \pi z\right)

Assumptions:

z \in \mathbb{C} \,\mathbin{\operatorname{and}}\, \tau \in \mathbb{H}

TeX:

\theta_2\!\left(z, \tau\right) = 2 \sum_{n=0}^{\infty} {e}^{\pi i {\left(n + 1 / 2\right)}^{2} \tau} \cos\!\left(\left(2 n + 1\right) \pi z\right)

z \in \mathbb{C} \,\mathbin{\operatorname{and}}\, \tau \in \mathbb{H}

Definitions:

Fungrim symbol	Notation	Short description
`JacobiTheta2`	$\theta_2\!\left(z, \tau\right)$	Jacobi theta function
`Exp`	${e}^{z}$	Exponential function
`ConstPi`	$\pi$	The constant pi (3.14...)
`ConstI`	$i$	Imaginary unit
`Pow`	${a}^{b}$	Power
`Infinity`	$\infty$	Positive infinity
`CC`	$\mathbb{C}$	Complex numbers
`HH`	$\mathbb{H}$	Upper complex half-plane

Source code for this entry:

Entry(ID("06633e"),
    Formula(Equal(JacobiTheta2(z, tau), Mul(2, Sum(Mul(Exp(Mul(Mul(Mul(ConstPi, ConstI), Pow(Add(n, Div(1, 2)), 2)), tau)), Cos(Mul(Mul(Add(Mul(2, n), 1), ConstPi), z))), Tuple(n, 0, Infinity))))),
    Variables(z, tau),
    Assumptions(And(Element(z, CC), Element(tau, HH))))

Topics using this entry

Jacobi theta functions