{ "id": "2007.15758", "version": "v1", "published": "2020-07-30T22:12:24.000Z", "updated": "2020-07-30T22:12:24.000Z", "title": "Eulerian dynamics in multi-dimensions with radial symmetry", "authors": [ "Changhui Tan" ], "comment": "34 pages, 6 figures", "categories": [ "math.AP" ], "abstract": "We study the global wellposedness of pressure-less Eulerian dynamics in multi-dimensions, with radially symmetric data. Compared with the 1D system, a major difference in multi-dimensional Eulerian dynamics is the presence of the spectral gap, which is difficult to control in general. We propose a new pair of scalar quantities that provides a significant better control of the spectral gap. Two applications are presented. (i) the Euler-Poisson equations: we show a sharp threshold condition on initial data that distinguish global regularity and finite time blowup; (ii) the Euler-alignment equations: we show a large subcritical region of initial data that leads to global smooth solutions.", "revisions": [ { "version": "v1", "updated": "2020-07-30T22:12:24.000Z" } ], "analyses": { "subjects": [ "35Q35" ], "keywords": [ "radial symmetry", "multi-dimensions", "initial data", "spectral gap", "significant better control" ], "note": { "typesetting": "TeX", "pages": 34, "language": "en", "license": "arXiv", "status": "editable" } } }