∫0∞e−atθ1(x,ibt)dt=abπcosh(bπa)sinh(2xbπa)
Assumptions:a∈CandRe(a)>0andb∈CandRe(b)>0andx∈[−21,21]
References:
- https://doi.org/10.1016/0022-0728(88)87001-3
TeX:
\int_{0}^{\infty} {e}^{-a t} \theta_{1}\!\left(x , i b t\right) \, dt = \sqrt{\frac{\pi}{a b}} \frac{\sinh\!\left(2 x \sqrt{\frac{\pi a}{b}}\right)}{\cosh\!\left(\sqrt{\frac{\pi a}{b}}\right)} a \in \mathbb{C} \;\mathbin{\operatorname{and}}\; \operatorname{Re}(a) > 0 \;\mathbin{\operatorname{and}}\; b \in \mathbb{C} \;\mathbin{\operatorname{and}}\; \operatorname{Re}(b) > 0 \;\mathbin{\operatorname{and}}\; x \in \left[-\frac{1}{2}, \frac{1}{2}\right]
Definitions:
Fungrim symbol | Notation | Short description |
---|---|---|
Integral | ∫abf(x)dx | Integral |
Exp | ez | Exponential function |
JacobiTheta | θj(z,τ) | Jacobi theta function |
ConstI | i | Imaginary unit |
Infinity | ∞ | Positive infinity |
Sqrt | z | Principal square root |
Pi | π | The constant pi (3.14...) |
CC | C | Complex numbers |
Re | Re(z) | Real part |
ClosedInterval | [a,b] | Closed interval |
Source code for this entry:
Entry(ID("8a857c"), Formula(Equal(Integral(Mul(Exp(Mul(Neg(a), t)), JacobiTheta(1, x, Mul(Mul(ConstI, b), t))), For(t, 0, Infinity)), Mul(Sqrt(Div(Pi, Mul(a, b))), Div(Sinh(Mul(Mul(2, x), Sqrt(Div(Mul(Pi, a), b)))), Cosh(Sqrt(Div(Mul(Pi, a), b))))))), Variables(a, b, x), Assumptions(And(Element(a, CC), Greater(Re(a), 0), Element(b, CC), Greater(Re(b), 0), Element(x, ClosedInterval(Neg(Div(1, 2)), Div(1, 2))))), References("https://doi.org/10.1016/0022-0728(88)87001-3"))