BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Niall Taggart (Queen's University Belfast) DTSTART:20251007T200000Z DTEND:20251007T210000Z DTSTAMP:20260422T212749Z UID:DiagramCategories/1 DESCRIPTION:Title: Algebraic models for functor calculus\nby Niall Taggart (Que en's University Belfast) as part of Diagram categories in homotopy theory\ n\n\nAbstract\nThere is a striking and useful analogy between equivariant homotopy theory and functor calculus. In the equivariant setting\, Greenle es conjectured that the category of rational G-spectra has an algebraic mo del - meaning it is equivalent to the derived category of an abelian categ ory with desirable finiteness properties. This talk will examine the funct or calculus counterpart of this conjecture in (potentially) more than one flavour of functor calculus. (Joint work with D. Barnes and M. Kedziorek.) \n LOCATION:https://researchseminars.org/talk/DiagramCategories/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Maxine Calle (University of Pennsylvania) DTSTART:20251028T200000Z DTEND:20251028T210000Z DTSTAMP:20260422T212749Z UID:DiagramCategories/2 DESCRIPTION:Title: Cut-and-paste K-theory of manifolds and SK-automorphisms\nby Maxine Calle (University of Pennsylvania) as part of Diagram categories i n homotopy theory\n\n\nAbstract\nGiven two manifolds M and N\, one can ask whether it is possible to cut M up into pieces and reassemble them to obt ain N. This “cut-and-paste” (SK) relation fits into the framework of s cissors congruence K-theory\, which is an extension of higher algebraic K- theory to more general settings. In this talk\, we will discuss a new mode l for the cut-and-paste K-theory of manifolds\, modeled on Waldhausen’s S-dot construction\, and describe how the first K-group is related to SK-a utomorphisms of manifolds\, i.e. the ways a manifold can be SK-equivalent to itself. This talk is based on joint work with Maru Sarazola.\n LOCATION:https://researchseminars.org/talk/DiagramCategories/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Steven Amelotte (Carleton University) DTSTART:20251202T210000Z DTEND:20251202T220000Z DTSTAMP:20260422T212749Z UID:DiagramCategories/3 DESCRIPTION:Title: Homotopy types of moment-angle complexes and almost linear resol utions\nby Steven Amelotte (Carleton University) as part of Diagram ca tegories in homotopy theory\n\n\nAbstract\nToric topology assigns to each simplicial complex $K$ a space with a torus action\, called the moment-ang le complex\, which is defined as a polyhedral product or (homotopy) colimi t over the face category of $K$. These spaces play a universal role in tor ic topology and control the homotopy groups of all toric manifolds. In thi s talk\, we consider the problem of reading off the homotopy types of thes e spaces from homological properties of their associated Stanley-Reisner r ings. In particular\, we show that the Hurewicz image of any moment-angle complex contains the linear strand of the corresponding Stanley-Reisner id eal\, and describe how this can be combined with some well-known results i n commutative algebra to analyze the formality and homotopy type of a larg e class of moment-angle manifolds and their loop spaces. This talk is base d on joint work with Ben Briggs.\n LOCATION:https://researchseminars.org/talk/DiagramCategories/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Valentina Zapata Castro (University of Massachusetts Amherst) DTSTART:20260113T210000Z DTEND:20260113T220000Z DTSTAMP:20260422T212749Z UID:DiagramCategories/4 DESCRIPTION:Title: Model categories in a grid\nby Valentina Zapata Castro (Univ ersity of Massachusetts Amherst) as part of Diagram categories in homotopy theory\n\n\nAbstract\nModel categories provide a powerful framework for a bstract homotopy theory\, but their complexity often makes them difficult to classify. By focusing on finite categories\, especially grids\, we gain a combinatorial setting where the problem becomes explicit. In this talk\ , we explore model structures through weak factorization systems (WFS) on posets\, which are in one-to-one correspondence with transfer systems and their duals\, both introduced here. This perspective leads to a method for constructing model structures and a characterization theorem for finding weak equivalence sets in posets. Our approach offers a pathway towards cla ssifying model structures in a controlled setting.\n\nThis is joint work w ith Kristen Mazur\, Angélica Osorno\, Constanze Roitzheim\, Rekha Santhan am and Danika Van Niel.\n LOCATION:https://researchseminars.org/talk/DiagramCategories/4/ END:VEVENT END:VCALENDAR