caa a22 4500 467931739 CHVBK 20180406152945.0 cr unu---uuuuu 170328e20060901xx s 000 0 eng 10.1007/s00020-005-1410-4 doi (NATIONALLICENCE)springer-10.1007/s00020-005-1410-4 Mixed Boundary Value Problems for the Helmholtz Equation in a Quadrant [Elektronische Daten] [L. Castro, F. Speck, F. Teixeira] Abstract.: The main objective is the study of a class of boundary value problems in weak formulation where two boundary conditions are given on the half-lines bordering the first quadrant that contain impedance data and oblique derivatives. The associated operators are reduced by matricial coupling relations to certain boundary pseudodifferential operators which can be analyzed in detail. Results are: Fredholm criteria, explicit construction of generalized inverses in Bessel potential spaces, eventually after normalization, and regularity results. Particular interest is devoted to the impedance problem and to the oblique derivative problem, as well. Birkhäuser Verlag, Basel, 2006 Boundary value problem nationallicence Helmholtz equation nationallicence half-line potential nationallicence pseudodifferential operator nationallicence Fredholm property nationallicence normalization nationallicence diffraction problem nationallicence Castro L. Department of Mathematics, University of Aveiro, 3810-193, Aveiro, Portugal aut Speck F. Department of Mathematics, I.S.T., Technical University of Lisbon, 1049-001, Lisbon, Portugal aut Teixeira F. Department of Mathematics, I.S.T., Technical University of Lisbon, 1049-001, Lisbon, Portugal aut Integral Equations and Operator Theory Birkhäuser-Verlag; www.birkhauser.ch 56/1(2006-09-01), 1-44 0378-620X 56:1<1 2006 56 20 https://doi.org/10.1007/s00020-005-1410-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00020-005-1410-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Castro L. Department of Mathematics, University of Aveiro, 3810-193, Aveiro, Portugal aut NATIONALLICENCE 700 1- Speck F. Department of Mathematics, I.S.T., Technical University of Lisbon, 1049-001, Lisbon, Portugal aut NATIONALLICENCE 700 1- Teixeira F. Department of Mathematics, I.S.T., Technical University of Lisbon, 1049-001, Lisbon, Portugal aut NATIONALLICENCE 773 0- Integral Equations and Operator Theory Birkhäuser-Verlag; www.birkhauser.ch 56/1(2006-09-01), 1-44 0378-620X 56:1<1 2006 56 20 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer