The role of planar symmetry and of symmetry constraints in the proof of existence of solutions to some scalar field equations

This paper deals with some recent results for scalar field equations in the case of a potential which converges from above to a limit at infinity. In particular, we shall collect some of the results of the authors which have contributed to partially answer a conjecture of Wei and Yan and we shall announce some results in a forthcoming paper to the aim of giving a short survey which collects the main ideas based on the use of symmetry assumptions and of symmetry methods introduced for the above problem.