Poisson Integral

Poisson Integral


(1) An integral of the form

where r and Φ are polar coordinates and θ is a parameter that varies over the closed interval [0, 2π]. Poisson’s integral expresses the values of a function u(r, Φ) that is harmonic within a circle of radius R in terms of the function’s values f(θ) on the boundary of this circle. The function u(r, Φ) is the solution of the Dirichlet problem for the circle. The Poisson integral was first examined by S. D. Poisson in 1823. A rigorous theory of the Poisson integral was constructed by H. Schwarz in 1869.

(2) The integral

which is encountered in probability theory and in certain problems in mathematical physics. Poisson suggested an extremely simple method of calculating this integral. Since the integral was first calculated in 1729 by L. Euler, it is sometimes called the Euler-Poisson integral.

References in periodicals archive ?
Boundary properties and applications of the differentiated Poisson integral for different domains.
Georgia) investigates the boundary properties of the differentiated Poisson integral for various domains such as circle, ball, half-plane, half-space, and bicylinder.
While intended for relative novices in the field, the author notes that readers should be acquainted with basic and complex analysis and the theory of the Poisson integral in the unit disk.