BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Stefan Waldmann (Julius Maximilian University Würzburg) DTSTART:20210222T150000Z DTEND:20210222T160000Z DTSTAMP:20260423T053017Z UID:NCGandPH/2 DESCRIPTION:Title: Convergence of Star Products: Examples and Concepts.\nby Stefan Waldm ann (Julius Maximilian University Würzburg) as part of Noncommutative Geo metry and Physics\n\n\nAbstract\nIn usual formal deformation quantization one considers formal \ndeformations of the algebra of functions on a Poiss on manifold viewing \nthem as observables of a mechanical system whose qua ntum version one \nis interested in. However\, there is yet another interp retation in \nterms of noncommutative geometry: the noncommutative product s can be \nviewed as models of noncommutative manifolds\, which\, in turn\ , can be \nused for describing space-time geometry at small distances etc. \n\nWhile formal deformation quantization has very general existence and \ nclassification results by Kontsevich's formality theorem\, it lacks the \ nimmediate applicability to physical problems: the deformation \nparameter (e.g. Planck's constant $\\hbar$ or the Planck length etc.) \nare formal only. Thus the understanding of the (non-) convergence of \nthe formal ser ies is one of the most important issues if one is \ninterested in finding more realistic models beyond an "infinitesimal" \ndeformation. Here in the recent years several classes of examples have \nbeen discussed. In my tal k I will report on some of these examples \nillustrating the underlying ge ometry as well as some of the quite \ninvolved functional-analytic questio ns.\n LOCATION:https://researchseminars.org/talk/NCGandPH/2/ END:VEVENT END:VCALENDAR