The partial differential equation
where is the real part of (Calogero and Degasperis 1982, p. 62; Zwillinger 1997, p. 131).
The partial differential equation
where is the real part of (Calogero and Degasperis 1982, p. 62; Zwillinger 1997, p. 131).
Weisstein, Eric W. "Ernst Equation." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ErnstEquation.html