Let Nge 3, R>rho >0 and A_{rho }:={xin mathbb {R}^N; rho<|x|<R}. Let U^{pm }_{n,rho }, nge 1, be a radial solution with n nodal domains of ΔU+|x|α|U|p-1U=0inAρ,U=0on∂Aρ.\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\begin{aligned} {\\left\\{ \\begin{array}{ll} \\Delta U+|x|^{\\alpha }|U|^{p-1}U=0 &{} \ ext {in}\\ A_{\\rho },\\\\ U=0 &{} \ ext {on}\\ \\partial A_{\\rho }. \\end{array}\\right. } \\end{aligned}$$\\end{document}We show that if p=frac{N+2+2alpha }{N-2}, alpha >-2 and Nge 3, then U^{pm }_{n,rho } is nondegenerate for small rho >0 and the Morse index {{textsf{m}}}(U^{pm }_{n,rho }) satisfies m(Un,ρ±)=n(N+2ℓ-1)(N+ℓ-1)!(N-1)!ℓ!for smallρ>0,\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\begin{aligned} {{\ extsf{m}}}(U^{\\pm }_{n,\\rho }) =n\\frac{(N+2\\ell -1)(N+\\ell -1)!}{(N-1)!\\ell !} \\quad \ ext {for small}\\ \\rho >0, \\end{aligned}$$\\end{document}where ell =[frac{alpha }{2}]+1. Using Jacobi elliptic functions, we show that if (p,alpha )=(3,N-4) and Nge 3, then the Morse index of a positive and negative solutions {{textsf{m}}}(U^{pm }_{1,rho }) is completely determined by the ratio rho /Rin (0,1). Upper and lower bounds for {{textsf{m}}}(U^{pm }_{n,rho }), nge 1, are also obtained when (p,alpha )=(3,N-4) and Nge 3.
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