Department of Mathematics2024-11-0920130031-900710.1103/PhysRevLett.110.2604022-s2.0-84879470304https://hdl.handle.net/20.500.14288/3600We introduce a notion of spectral singularity that applies for a general class of nonlinear Schrodinger operators involving a confined nonlinearity. The presence of the nonlinearity does not break the parity-reflection symmetry of spectral singularities but makes them amplitude dependent. Nonlinear spectral singularities are, therefore, associated with a resonance effect that produces amplified waves with a specific amplitude-wavelength profile. We explore the consequences of this phenomenon for a complex delta-function potential that is subject to a general confined nonlinearity.pdfMathematicsMultidisciplinaryJournal Article1079-7114https://doi.org/10.1103/PhysRevLett.110.260402320960300001N/ANOIR00087