BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:The motivic fundamental groupoid at tangential basepoints
DTSTART:20260529T120000Z
DTEND:20260529T130000Z
DTSTAMP:20260522T164200Z
UID:indico-event-16625@indico.math.cnrs.fr
DESCRIPTION:Speakers: Sofian Tur Dorvault\n\nIf U s a smooth scheme over a
  subfield of the field of complex numbers\, it is known from the work of P
 ierre Deligne and Alexander Goncharov that the prounipotent completion of 
 the fundamental group of U based at any point has a motivic incarnation. M
 ore precisely\, its coordinate ring arises as the degree-zero homology of 
 the Betti realization of a Hopf algebra object in Voevodsky's triangulated
  category of motives. More generally\, he conjectured a similar property f
 or the fundamental group based at a "point at infinity"\, i.e. the datum o
 f a point x on a smooth compactification of  with normal crossings bound
 ary\, together with the datum of a tangent vector at x\, normal to the bou
 ndary. While Deligne and Goncharov proved this conjecture in the case of t
 he projective line minus three points\, the general case remained still op
 en. In this talk\, I will explain how logarithmic geometry\, together with
  the notion of virtual morphisms between log schemes\, allows one to const
 ruct the motivic fundamental group in full generality and to compute its r
 ealizations.\n\nhttps://indico.math.cnrs.fr/event/16625/
LOCATION:M7-411 (UMPA)
URL:https://indico.math.cnrs.fr/event/16625/
END:VEVENT
END:VCALENDAR