BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4//
BEGIN:VEVENT
UID:20251122T002246EST-11435HuvbI@132.216.98.100
DTSTAMP:20251122T052246Z
DESCRIPTION:Title: Calculus in homotopy theory.\n\nAbstract: (joint with M.
  Anel\, E. Finster and A. Joyal)\n	\n	In classical calculus one studies smoo
 th functions via their Taylor series. Its $n$-th homogeneous layer is gove
 rned by a single coefficient: the $n$-th derivative. As part of his effort
  to relate algebraic K-theory to topological cyclic homology Goodwillie du
 ring the 90s introduced 'Goodwillie calculus' to homotopy theory. A homoto
 py invariant functor is viewed as an analogue of a smooth function and res
 olved into a tower whose $n$-th homogeneous layer is governed by a single 
 coefficient: a spectrum (in the sense of homotopy theory) with $Sigma_n$-a
 ction. Goodwillie calculus is now a central tool in homotopy theory. Aroun
 d the same time (and influenced by Goodwillie) Michael Weiss constructed '
 orthogonal calculus': space-valued functors from the category of finite di
 mensional Euclidean vector spaces with morphism given by Stiefel manifolds
  are resolved into an orthogonal tower whose $n$-th homogeneous layer is g
 overned by a spectrum with an action by $O(n)$. Weiss' theory has found ma
 ny applications in differential topology. People have wondered for a long 
 time whether both theories have a common description. We can give one. In 
 fact\, it turns out that the theory of $infty$-topoi is the perfect langua
 ge. For any left exact localization $L$ of an $infty$-topos we construct a
  tower $(P_n)_{nge 0}$ of left exact localizations such that $P_0=L$. The 
 pointed objects of the layers form stable $infty$-categories. The tower is
  analogous to the completion tower of a commutative ring with respect to a
 n ideal. It specializes to Goodwillie's and Weiss' tower. I am going to te
 ll you a bit about all these towers.\n\nLocation: 201\, avenue du Présiden
 t-Kennedy\, PK-5115\, UQAM\, Montréal\n\nWeb site : https://www.cirget.uqa
 m.ca/fr/seminaires.html\n\n \n
DTSTART:20221021T150000Z
DTEND:20221021T160000Z
SUMMARY:Georg Biedermann (Universidad del Norte)
URL:/mathstat/channels/event/georg-biedermann-universi
 dad-del-norte-342832
END:VEVENT
END:VCALENDAR