BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Michele Zaccaron (UMA\, ENSTA Paris) DTSTART:20260216T144000Z DTEND:20260216T161000Z DTSTAMP:20260405T175009Z UID:NSCM/202 DESCRIPTION:Title: B ending and twisting of electromagnetic waveguides\nby Michele Zaccaron (UMA\, ENSTA Paris) as part of Nečas Seminar on Continuum Mechanics\n\nL ecture held in Room K3\, Faculty of Mathematics and Physics\, Charles Uni versity\, Sokolovská 83 Prague 8..\n\nAbstract\nConsider a reference hom ogeneous and isotropic electromagnetic waveguide\nwith a simply connected cross-section embedded in a perfect conductor. In\nthis setting\, when the waveguide is straight\, the spectrum of the associated\nself-adjoint Maxw ell operator with a constant twist (which may be zero) is\nentirely essent ial\, lies on the real line and is symmetric with respect to zero\,\nexhib iting a gap around the origin.\nIn this talk\, we present new results on t he effects of the geometric defor-\nmations of bending and twisting on the spectrum of the Maxwell operator.\nMore precisely\, we provide\, on the o ne hand\, sufficient conditions on the\nasymptotic behaviour of the curvat ure and twist of a perturbed waveguide\nensuring the preservation of the e ssential spectrum. Our approach relies on\na Birman-Schwinger-type princip le which has an interest of its own. On the\nother hand\, we give sufficie nt conditions\, involving in particular the shape of\nthe cross-section\, so that the geometrical deformation creates discrete spec-\ntrum within th e gap\, and give some insight into its localization. Finally\, we\nshow so me theoretical and numerical results further investigating the suffi-\ncie nt condition involving the geometry of the cross-section.\nBased on joint work with Philippe Briet\, Maxence Cassier and Thomas Ourmieres-Bonafos.\n LOCATION:https://researchseminars.org/talk/NSCM/202/ END:VEVENT END:VCALENDAR