Thomas Kappeler
Institut für Mathematik, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland E-mail: thomas.kappeler@math.uzh.ch
Yannick Widmer
Institut für Mathematik, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland E-mail: Yannick.Widmer@math.uzh.ch
Received February 15, 2018.
To Professor Vladimir Aleksandrovich Marchenko on the occasion of his ninety fifth birthday
Abstract
We analyze the periodic spectrum of the L operator in the Lax pair of the sine-Gordon equation in terms of the regularity of the potential.
Mathematics Subject Classification 2000: 37K10, 35Q55.Key words: sine-Gordon equation, sinh-Gordon equation, Lax pair, decay properties of gap lengths.