BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Barbara Schapira (Université Rennes 1) DTSTART:20210315T143000Z DTEND:20210315T154500Z DTSTAMP:20260423T021350Z UID:BODS/10 DESCRIPTION:Title: St rong positive recurrence for geodesic flows\nby Barbara Schapira (Univ ersité Rennes 1) as part of Bremen Online Dynamics Seminar\n\n\nAbstract\ nIn a recent paper with S Gouezel and S Tapie\, in the context of geodesic \nflows of noncompact negatively curved manifolds\, we propose three\ndiff erent definitions of entropy and pressure at infinity\, through\ngrowth of periodic orbits\, critical exponents of Poincaré series\, and\nentropy ( pressure) of invariant measures. We show that these notions\ncoincide. Tha nks to these entropy and pressure at infinity\, we\ninvestigate thoroughly the notion of strong positive recurrence in this\ngeometric context. A po tential is said strongly positively recurrent\nwhen its pressure at infini ty is strictly smaller than the full\ntopological pressure. We show in par ticular that if a potential is\nstrongly positively recurrent\, then it ad mits a finite Gibbs measure. We\nalso provide easy criteria allowing to bu ild such strong positively\nrecurrent potentials and many examples.\n\nDur ing the talk\, I will present some of these points\, to give to the\naudie nce the flavour of this work.\n LOCATION:https://researchseminars.org/talk/BODS/10/ END:VEVENT END:VCALENDAR