{ "id": "2110.07154", "version": "v3", "published": "2021-10-14T05:03:58.000Z", "updated": "2023-07-31T06:03:36.000Z", "title": "Decay estimates for fourth-order Schrödinger operators in dimension two", "authors": [ "Ping Li", "Avy Soffer", "Xiaohua Yao" ], "comment": "62 Pages. This is a final version which was published in JFA 2023", "categories": [ "math.AP", "math-ph", "math.MP" ], "abstract": "In this paper we study the decay estimates of the fourth order Schr\\\"{o}dinger operator $H=\\Delta^{2}+V(x)$ on $\\mathbb{R}^2$ with a bounded decaying potential $V(x)$. We first deduce the asymptotic expansions of resolvent of $H$ near the zero threshold in the presence of resonances or eigenvalue, and then use them to establish the $L^1-L^\\infty$ decay estimates of $e^{-itH}$generated by the fourth order Schr\\\"{o}dinger operator $H$. Our methods used in the decay estimates depend on Littlewood-Paley decomposition and oscillatory integral theory. Moreover, we classify these zero resonances as the distributional solutions of $H\\phi=0$ in suitable weighted spaces. Due to the degeneracy of $\\Delta^{2}$ at zero threshold and the lower even dimension (i.e. $n=2$), we remark that the asymptotic expansions of resolvent $R_V(\\lambda^4)$ and the classifications of resonances are more involved than Schr\\\"odinger operator $-\\Delta+V$ in dimension two.", "revisions": [ { "version": "v3", "updated": "2023-07-31T06:03:36.000Z" } ], "analyses": { "keywords": [ "decay estimates", "fourth-order schrödinger operators", "asymptotic expansions", "zero threshold", "fourth order" ], "note": { "typesetting": "TeX", "pages": 62, "language": "en", "license": "arXiv", "status": "editable" } } }