Fungrim entry: f12569

\theta_{2}\!\left(2 z , 2 \tau\right) = \frac{\theta_{1}\!\left(\frac{1}{4} - z , \tau\right) \theta_{1}\!\left(\frac{1}{4} + z , \tau\right)}{\theta_{4}\!\left(0 , 2 \tau\right)}

Assumptions:

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

TeX:

\theta_{2}\!\left(2 z , 2 \tau\right) = \frac{\theta_{1}\!\left(\frac{1}{4} - z , \tau\right) \theta_{1}\!\left(\frac{1}{4} + z , \tau\right)}{\theta_{4}\!\left(0 , 2 \tau\right)}

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

Definitions:

Fungrim symbol	Notation	Short description
`JacobiTheta`	$\theta_{j}\!\left(z , \tau\right)$	Jacobi theta function
`CC`	$\mathbb{C}$	Complex numbers
`HH`	$\mathbb{H}$	Upper complex half-plane

Source code for this entry:

Entry(ID("f12569"),
    Formula(Equal(JacobiTheta(2, Mul(2, z), Mul(2, tau)), Div(Mul(JacobiTheta(1, Sub(Div(1, 4), z), tau), JacobiTheta(1, Add(Div(1, 4), z), tau)), JacobiTheta(4, 0, Mul(2, tau))))),
    Variables(z, tau),
    Assumptions(And(Element(z, CC), Element(tau, HH))))

Topics using this entry

Lattice transformations for Jacobi theta functions