{ "id": "1510.08347", "version": "v1", "published": "2015-10-28T15:31:13.000Z", "updated": "2015-10-28T15:31:13.000Z", "title": "On the periodic and asymptotically periodic nonlinear Helmholtz equation", "authors": [ "Gilles Evequoz" ], "categories": [ "math.AP" ], "abstract": "In the first part of this paper, the existence of infinitely many $L^p$-standing wave solutions for the nonlinear Helmholtz equation $$ -\\Delta u -\\lambda u=Q(x)|u|^{p-2}u\\quad\\text{ in }\\mathbb{R}^N $$ is proven under the assumptions $N\\geq 3$, $\\lambda>0$, $Q\\in L^\\infty(\\mathbb{R}^N)$, $\\mathbb{Z}^N$-periodic, $Q\\geq 0$, $Q\\not\\equiv 0$ and for $p$ in the subcritical range $\\frac{2(N+1)}{N-1}