where is a Legendre polynomial.
Mehler-Dirichlet Integral
See also
Laplace's Integral, Laplace-Mehler Integral, Legendre PolynomialExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Mehler-Dirichlet Integral." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Mehler-DirichletIntegral.html