Electronic Journal of Differential Equations,
Vol. 2021 (2021), No. 12, pp. 1-24.

Title: Multiple solutions for semilinear Robin problems with superlinear reaction and no symmetries
       
Authors: Nikolaos S. Papageorgiou (National Technical Univ., Athens, Greece)
         Calogero Vetro (Univ. of Palermo, Italy)
         Francesca Vetro (Palermo, Italy)

Abstract:
 We study a semilinear Robin problem driven by the Laplacian with a parametric
 superlinear reaction.  Using variational tools from the critical point theory
 with truncation and comparison techniques, critical groups and flow
 invariance arguments, we show the existence of seven nontrivial smooth solutions,
 all with sign information and ordered.

Submitted  February 15, 2021. Published March 10, 2021.
Math Subject Classifications: 35J20, 35J61.
Key Words: Constant sign and nodal solutions; superlinear reaction;
           critical point theory; critical groups; flow invariance.