Abstract :
In this paper, we study the effect of the graph of weight functions on the number
of 2-nodal solutions for semilinear elliptic problems in RN . Our results generalize and
improve on the results of [D. Cao, E.S. Noussair, Multiplicity of positive and nodal solutions
for nonlinear elliptic problems in RN, Ann. Inst. H. Poincaré Anal. Non Linéaire 13 (5)
(1996) 567–588]. In the present paper, we give a new analytical method to study this
issue.
