# Weber equation

A second-order ordinary linear differential equation:

$$y''+\left(\nu+\frac12-\frac{x^2}{4}\right)y=0,\quad\nu=\text{const},\tag{*}$$

in which the point $x=\infty$ is strongly singular (cf. Singular point). An equation of this type was first studied by H. Weber in potential theory in connection with the parabolic cylinder ; it is the result of separation of variables for the Laplace equation in parabolic coordinates. The substitution $y=x^{-1/2}w$, $z=x^2/2$ converts the Weber equation to the Whittaker equation. It is a special case of a confluent hypergeometric equation. The substitution $y=u\exp(-x^2/4)$ converts Weber's equation into

$$u''-xu'+\nu u=0.$$

Solutions of equation (*) are known as parabolic cylinder functions or as Weber–Hermite functions. In particular, if $\nu$ is a non-negative integer, equation (*) is satisfied by the function

$$y=\exp(-x^2/4)H_\nu(x),$$

where $H_\nu(x)$ is the Hermite polynomial (cf. Hermite polynomials) , , .

How to Cite This Entry:
Weber equation. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Weber_equation&oldid=44359
This article was adapted from an original article by N.Kh. Rozov (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article