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TZID:Europe/Paris
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BEGIN:VEVENT
UID:1-453@lptms.universite-paris-saclay.fr
DTSTART:20160908T110000Z
DTEND:20160908T120000Z
DTSTAMP:20160903T184241Z
URL:http://www.lptms.universite-paris-saclay.fr/seminars/seminaire-du-lptm
 s-christian-hagendorf-seminaire-exceptionnel/
SUMMARY:Séminaire du LPTMS: Christian Hagendorf *** séminaire exceptionne
 l *** - LPTMS\, salle 201\, 2ème étage\, Bât 100\, Campus d'Orsay - 8 S
 ep 16 11:00
DESCRIPTION:The spin one XXZ chain and symmetry classes of alternating sign
  matrices\nChristian Hagendorf (Université Catholique de Louvain\, Belgiq
 ue)\nThe spin 1/2 XXZ Heisenberg chain is a prototype model in the statist
 ical mechanics of magnetism. It describes the interaction of localised spi
 ns on a one-dimensional chain with anisotropy. In 2000\, Razumov and Strog
 anov observed for a particular anisotropy a surprising appearance of integ
 er sequences in the spin-chain ground state. These sequences enumerate so-
 called alternating sign matrices. They are well known to combinatorialists
  through rather different problems such as determinant calculus or the enu
 meration of plane partitions. In this talk\, I give an overview of the rel
 ation between spin chains\, models of statistical mechanics and alternatin
 g sign matrices. Furthermore\, I discuss the spin one XXZ chain whose grou
 nd state displays for any anisotropy connections to enumeration problems
  of alternating sign matrices with symmetries. The proof of these connecti
 ons uses tools from quantum integrability\, in particular the algebraic Be
 the ansatz and the quantum separation of variables method. (Joint work wit
 h Alexi Morin-Duchèsne)
CATEGORIES:seminars
LOCATION:LPTMS\, salle 201\, 2ème étage\, Bât 100\, Campus d'Orsay\, 15 
 Rue Georges Clemenceau\, Orsay\, 91405\, France
GEO:48.698185;2.181768
X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=15 Rue Georges Clemenceau\,
  Orsay\, 91405\, France;X-APPLE-RADIUS=100;X-TITLE=LPTMS\, salle 201\, 2è
 me étage\, Bât 100\, Campus d'Orsay:geo:48.698185,2.181768
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