{ "id": "2407.08997", "version": "v1", "published": "2024-07-12T05:32:21.000Z", "updated": "2024-07-12T05:32:21.000Z", "title": "Asymptotic Expansions for Semilinear Waves on Asymptotically Flat Spacetimes", "authors": [ "Shi-Zhuo Looi", "Haoren Xiong" ], "categories": [ "math.AP", "gr-qc" ], "abstract": "We establish precise asymptotic expansions for solutions to semilinear wave equations with power-type nonlinearities on asymptotically flat spacetimes. For cubic nonlinearities $a(t,x)\\phi^3$, we prove $\\phi(t, x) = 2c_0 t^{-2} + O(t^{-3+})$ in compact spatial regions, with $c_0$ computable. For $a(t,x)\\phi^p$ with $p \\geq 4$, we show $\\phi(t, x) = d t^{-3} + O(t^{-4+})$, extending Price's law to the nonlinear setting. Our approach combines radiation field analysis with a generalized low-energy resolvent expansion, providing a bridge between spectral and physical space methods. These results sharpen previous decay estimates and yield complete asymptotics across the entire spacetime, including black hole backgrounds.", "revisions": [ { "version": "v1", "updated": "2024-07-12T05:32:21.000Z" } ], "analyses": { "keywords": [ "asymptotically flat spacetimes", "black hole backgrounds", "radiation field analysis", "semilinear wave equations", "establish precise asymptotic expansions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }