BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Jean-Philippe Labbé (École de Technologie Supérieure Montreal) DTSTART:20211028T141500Z DTEND:20211028T160000Z DTSTAMP:20260422T070001Z UID:CJCS/34 DESCRIPTION:Title: Li neup polytopes and applications in quantum physics\nby Jean-Philippe L abbé (École de Technologie Supérieure Montreal) as part of Copenhagen-J erusalem Combinatorics Seminar\n\n\nAbstract\nThe set of all possible spec tra of 1-reduced density operators for systems of N\nparticles on a d-dime nsional Hilbert space is a polytope called hypersimplex. If\nthe spectrum of the original density operators is fixed\, the set of spectra (ordered\n decreasingly) of 1-reduced density operators is also a polytope. A theoret ical\ndescription of this polytope using inequalities was provided by Klya chko in the\nearly 2000’s.\nAdapting and enhancing tools from discrete g eometry and combinatorics (symmetric\npolytopes\, sweep polytopes\, and th e Gale order)\, we obtained such necessary\ninequalities explicitly\, that are furthermore valid for arbitrarily large N and d.\nThese may therefore be interpreted as generalizations of Pauli's exclusion principle\nfor fer mions. In particular\, this approach leads to a new class of polytopes cal led\nlineup polytopes.\n\nThis is joint work with physicists Julia Liebert \, Christian Schilling and mathematicians\nEva Philippe\, Federico Castill o and Arnau Padrol.\n LOCATION:https://researchseminars.org/talk/CJCS/34/ END:VEVENT END:VCALENDAR