TY - JOUR A1 - Weth, Tobias A1 - Yeşil, Tolga T1 - Fourier extension estimates for symmetric functions and applications to nonlinear Helmholtz equations T2 - Annali di matematica pura ed applicata N2 - We establish weighted Lp-Fourier extension estimates for O(N−k)×O(k)-invariant functions defined on the unit sphere SN−1, allowing for exponents p below the Stein–Tomas critical exponent 2(N+1)/N−1. Moreover, in the more general setting of an arbitrary closed subgroup G⊂O(N) and G-invariant functions, we study the implications of weighted Fourier extension estimates with regard to boundedness and nonvanishing properties of the corresponding weighted Helmholtz resolvent operator. Finally, we use these properties to derive new existence results for G-invariant solutions to the nonlinear Helmholtz equation −Δu−u = Q(x)|u|p−2u,u∈W2,p(RN), where Q is a nonnegative bounded and G-invariant weight function. Y1 - 2021 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/63805 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-638052 SN - 1618-1891 N1 - Open Access funding enabled and organized by Projekt DEAL. N1 - T. Weth and T. Yeşil are supported by the German Science Foundation (DFG) within the project WE-2821/5-2. VL - 200.2021 IS - 6 SP - 2423 EP - 2454 PB - Springer CY - Berlin ; Heidelberg [u.a.] ER -