2020/11/24 by Ricceri, Biagio
#Analysis of PDEs (math.AP) #FOS: Mathematics
paper · doi:10.48550/arxiv.2011.12347
We get a new multiplicity result for gradient systems. Here is a very particular corollary: Let Ω⊂ \bf Rn (n≥ 2) be a smooth bounded domain and let Φ:\bf R2→ \bf R be a C1 function, with Φ(0,0)=0, such that sup_(u,v)∈ \bf R2|Φu(u,v)|+|Φv(u,v)|\over 1+|u|p+|v|p0, with p=2\over n-2 when ngt;2. Then, for every convex set S⊆ L∞(Ω)× L∞(Ω) dense in L2(Ω)× L2(Ω), there exists (α,β)∈ S such that the problem\cases -Δu=(α(x)cos(Φ(u,v))-β(x)sin(Φ(u,v)))Φu(u,v) & in Ω \cr & \cr -Δv= (α(x)cos(Φ(u,v))-β(x)sin(Φ(u,v)))Φv(u,v) & in Ω \cr & \cr u=v=0 & on ∂Ω\crhas at least three weak solutions, two of which are global minima in H10(Ω)× H10(Ω) of the functional(u,v)→ 1\over 2 ( ∫Ω|∇ u(x)|2dx+∫Ω|∇ v(x)|2dx )-∫Ω(α(x)sin(Φ(u(x),v(x)))+β(x)cos(Φ(u(x),v(x))))dx .