Extremal spectral properties of Lawson tau-surfaces and the Lamé equation

Abstract: Extremal spectral properties of Lawson tau-surfaces are investigated. The Lawson tau-surfaces form a two-parametric family of tori or Klein bottles minimally immersed in the standard unitary three-dimensional sphere. A Lawson tau-surface carries an extremal metric for some eigenvalue of the Laplace-Beltrami operator. Using theory of the Lam\'e equation we find explicitly these extremal eigenvalues.