Morse complex, even functionals and asymptotically linear differential equations with resonance at infinity (Q1305304)

The authors suggest a Morse complex based method for studying variational problems that are degenerate in a certain sense and have group symmetries. The basic ideas (as the authors remark) behind the approach presented in this paper go back to \textit{E. Schwartzman} [`On a homotopy invariant of potential fields' (1989), preprint], where the Morse complex based method was used to obtain a multiplicity result for finite-dimensional even functionals. This paper is a revised version of \textit{Z. Balanov} and \textit{E. Schwartzman} [`Morse complex, even functionals and asymptotically linear problems with resonance at infinity', LMU München, (1996), preprint]. A few of the results of this paper were announced by the authors in [Appl. Math. Lett. 10, No. 5, 35-39 (1997; Zbl 0886.35062)].