Theta function (disambiguation)

Theta functions $\vartheta (z;\tau )$ are special functions of several complex variables. Theta function may also refer to:

Jacobi-related functions:

• Q-theta function $\theta (z;q)$, a type of q-series
• Theta function of a lattice $\Theta _{\Lambda }(\tau )$, a holomorphic function on the upper half-plane
• Mock theta functions $\mu (q),f(q),\phi (q),\psi (q),\chi (q)$, etc., a mock modular form of weight 1/2
• Ramanujan theta function $f(a,b)$

Other functions:

• Riemann–Siegel theta function $\theta (t)$
• Chebyshev function $\vartheta (x)$
• Feferman's function $\theta _{\alpha }(\beta )$
• Heaviside step function sometimes denoted $\theta (x)$

See also

• Jacobi theta functions (notational variations) $\vartheta _{ij}(z;\tau ),\vartheta _{j}(z),\theta _{i}(z;q)$