this paper is devoted to the spectral theory (more precisely, tothe variational theory of the spectrum) of guided waves in anelastic half cylinder.  we use variational methods to investigateseveral aspects of propagating waves, including localization (seefigure 1), existence criteria and the formulas to find them. weapproach the problem using two complementary methods: thevariational methods fo...

this paper is devoted to the spectral theory (more precisely, tothe variational theory of the spectrum) of guided waves in anelastic half cylinder.  we use variational methods to investigateseveral aspects of propagating waves, including localization (seefigure 1), existence criteria and the formulas to find them. weapproach the problem using two complementary methods: thevariational methods fo...

Content The first paper by Jean Mawhin on critical point theory [] was published in  and was devoted to periodic solutions of a forced pendulum equation. One of the most recent papers in  [] concerns periodic solutions of difference systems with φ-Laplacian. It is impossible to describe all the contributions. We have selected  articles,  books and some fundamental topics: the force...