RT Journal Article T1 On the existence of positive solutions and solutions with compact support for a spectral nonlinear elliptic problem with strong absorption A1 Díaz Díaz, Jesús Ildefonso A1 Hernández, J. A1 Ilyasov, Y. AB We study a semilinear elliptic equation with a strong absorption term given by a non-Lipschitz function. The motivation is related with study of the linear Schrödinger equation with an infinite well potential. We start by proving a general existence result for non-negative solutions. We use also variational methods, more precisely Nehari manifolds, to prove that for any λ>λ1 (the first eigenvalue of the Laplacian operator) there exists (at least) a non-negative solution. These solutions bifurcate from infinity at λ1 and we obtain some interesting additional information. We sketch also an asymptotic bifurcation approach, in particular this shows that there exists an unbounded continuum of non-negative solutions bifurcating from infinity at λ=λ1. We prove that for some neighborhood of (λ1,+∞) the positive solutions are unique. Then Pohozaev’s identity is introduced and we study the existence (or not) of free boundary solutions and compact support solutions. We obtain several properties of the energy functional and associated quantities for the ground states, together with asymptotic estimates in λ, mostly for λ↗λ1. We also consider the existence of solutions with compact support in Ω for λ large enough. PB Elsevier SN 0362-546X YR 2015 FD 2015-06 LK https://hdl.handle.net/20.500.14352/24022 UL https://hdl.handle.net/20.500.14352/24022 LA eng NO Unión Europea. FP7 NO DGISPI (Spain) NO UCM Research Group MOMAT DS Docta Complutense RD 11 may 2025