{ "id": "1709.02118", "version": "v1", "published": "2017-09-07T07:41:49.000Z", "updated": "2017-09-07T07:41:49.000Z", "title": "Detecting a hidden obstacle via the time domain enclosure method. A scalar wave case", "authors": [ "Masaru Ikehata" ], "comment": "25 pages", "categories": [ "math.AP" ], "abstract": "The characterization problem of the existence of an unknown obstacle behind a known obstacle is considered by using a singe observed wave at a place where the wave is generated. The unknown obstacle is invisible from the place by using visible ray. A mathematical formulation of the problem using the classical wave equation is given. The main result consists of two parts: (i) one can make a decision whether the unknown obstacle exists or not behind a known impenetrable obstacle by using a single wave over a finte time interval under some a-priori information on the position of the unknown obstacle; (ii) one can obtain a lower bound of the Euclidean distance of the unknown obstacle to the center point of the support of the intial data of the wave. The proof is a combination of the time domain enclosure method and some previous results on the Gaussian lower estimates for the heat kernels.", "revisions": [ { "version": "v1", "updated": "2017-09-07T07:41:49.000Z" } ], "analyses": { "subjects": [ "35R30", "35L05", "35K08" ], "keywords": [ "time domain enclosure method", "scalar wave case", "unknown obstacle", "hidden obstacle", "gaussian lower estimates" ], "note": { "typesetting": "TeX", "pages": 25, "language": "en", "license": "arXiv", "status": "editable" } } }