BEGIN:VCALENDAR
VERSION:2.0
PRODID:researchseminars.org
CALSCALE:GREGORIAN
X-WR-CALNAME:researchseminars.org
BEGIN:VEVENT
SUMMARY:Thomas Grubb (UCSD)
DTSTART:20211021T210000Z
DTEND:20211021T220000Z
DTSTAMP:20260423T022806Z
UID:UCSD_NTS/44
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/UCSD_NTS/44/
 ">A cut-by-curves criterion for overconvergence of $F$-isocrystals</a>\nby
  Thomas Grubb (UCSD) as part of UCSD number theory seminar\n\nLecture held
  in APM 7321 and online.\n\nAbstract\nLet $X$ be a smooth\, geometrically 
 irreducible scheme over a finite field of characteristic $p > 0$. With res
 pect to rigid cohomology\, $p$-adic coefficient objects on $X$ come in two
  types: convergent $F$-isocrystals and the subcategory of overconvergent $
 F$-isocrystals. Overconvergent isocrystals are related to $\\ell$-adic eta
 le objects ($\\ell\\neq p$) via companions theory\, and as such it is desi
 rable to understand when an isocrystal is overconvergent. We show (under a
  geometric tameness hypothesis) that a convergent $F$-isocrystal $E$ is ov
 erconvergent if and only if its restriction to all smooth curves on $X$ is
 . The technique reduces to an algebraic setting where we use skeleton shea
 ves and crystalline companions to compare $E$ to an isocrystal which is pa
 tently overconvergent. Joint with Kiran Kedlaya and James Upton.\n\npre-ta
 lk at 1:30\n
LOCATION:https://researchseminars.org/talk/UCSD_NTS/44/
END:VEVENT
END:VCALENDAR