{ "id": "1407.6750", "version": "v2", "published": "2014-07-24T22:35:20.000Z", "updated": "2015-07-21T01:50:51.000Z", "title": "Combined effects of two nonlinearities in lifespan of small solutions to semi-linear wave equations", "authors": [ "Kunio Hidano", "Chengbo Wang", "Kazuyoshi Yokoyama" ], "comment": "Substantially revised and expanded. 22 pages, 5 figures", "categories": [ "math.AP" ], "abstract": "This paper investigates the combined effects of two distinctive power-type nonlinear terms (with parameters $p,q>1$) in the lifespan of small solutions to semi-linear wave equations. We determine the full region of $(p,q)$ to admit global existence of small solutions, at least for spatial dimensions $n=2, 3$. Moreover, for many $(p,q)$ when there is no global existence, we obtain sharp lower bound of the lifespan, which is of the same order as the upper bound of the lifespan.", "revisions": [ { "version": "v1", "updated": "2014-07-24T22:35:20.000Z", "abstract": "This paper investigates combined effects of two nonlinearities in lifespan of small solutions to semi-linear wave equations. Using the method of vector fields in Klainerman (Comm. Pure Appl. Math. 38 (1985), 321--332) together with some of techniques developed in Li and Zhou (Indiana Univ. Math. J. 44 (1995), 1207--1248), we show that the upper bound on the lifespan recently obtained by Han and Zhou (Comm. Partial Differential Equations 39 (2014), 651--665) is sharp in general, at least in space dimensions n=2, 3. Moreover, we also show that in the threshold case, the equation admits global (in time) solutions.", "comment": "29 pages, no figures", "journal": null, "doi": null }, { "version": "v2", "updated": "2015-07-21T01:50:51.000Z" } ], "analyses": { "subjects": [ "35L05", "35L15", "35L71" ], "keywords": [ "semi-linear wave equations", "small solutions", "nonlinearities", "equation admits global", "partial differential equations" ], "note": { "typesetting": "TeX", "pages": 22, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1407.6750H" } } }