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:20260404T094701Z UID:DiagramCategories/1 DESCRIPTION:Title: Algebraic models for functor calculus\nby Niall Tagga rt (Queen's University Belfast) as part of Diagram categories in homotopy theory\n\n\nAbstract\nThere is a striking and useful analogy between equiv ariant homotopy theory and functor calculus. In the equivariant setting\, Greenlees conjectured that the category of rational G-spectra has an algeb raic model - meaning it is equivalent to the derived category of an abelia n category with desirable finiteness properties. This talk will examine th e functor calculus counterpart of this conjecture in (potentially) more th an one flavour of functor calculus. (Joint work with D. Barnes and M. Kedz iorek.)\n LOCATION:https://stable.researchseminars.org/talk/DiagramCategories/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Maxine Calle (University of Pennsylvania) DTSTART:20251028T200000Z DTEND:20251028T210000Z DTSTAMP:20260404T094701Z UID:DiagramCategories/2 DESCRIPTION:Title: Cut-and-paste K-theory of manifolds and SK-automorphisms< /a>\nby Maxine Calle (University of Pennsylvania) as part of Diagram categ ories in 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 obtain N. This “cut-and-paste” (SK) relation fits into the framewo rk of scissors congruence K-theory\, which is an extension of higher algeb raic K-theory to more general settings. In this talk\, we will discuss a n ew model for the cut-and-paste K-theory of manifolds\, modeled on Waldhaus en’s S-dot construction\, and describe how the first K-group is related to SK-automorphisms of manifolds\, i.e. the ways a manifold can be SK-equi valent to itself. This talk is based on joint work with Maru Sarazola.\n LOCATION:https://stable.researchseminars.org/talk/DiagramCategories/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Steven Amelotte (Carleton University) DTSTART:20251202T210000Z DTEND:20251202T220000Z DTSTAMP:20260404T094701Z UID:DiagramCategories/3 DESCRIPTION:Title: Homotopy types of moment-angle complexes and almost linea r resolutions\nby Steven Amelotte (Carleton University) as part of Dia gram categories in homotopy theory\n\n\nAbstract\nToric topology assigns t o each simplicial complex $K$ a space with a torus action\, called the mom ent-angle complex\, which is defined as a polyhedral product or (homotopy) colimit over the face category of $K$. These spaces play a universal role in toric topology and control the homotopy groups of all toric manifolds. In this talk\, we consider the problem of reading off the homotopy types of these spaces from homological properties of their associated Stanley-Re isner rings. In particular\, we show that the Hurewicz image of any moment -angle complex contains the linear strand of the corresponding Stanley-Rei sner ideal\, and describe how this can be combined with some well-known re sults in commutative algebra to analyze the formality and homotopy type of a large class of moment-angle manifolds and their loop spaces. This talk is based on joint work with Ben Briggs.\n LOCATION:https://stable.researchseminars.org/talk/DiagramCategories/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Valentina Zapata Castro (University of Massachusetts Amherst) DTSTART:20260113T210000Z DTEND:20260113T220000Z DTSTAMP:20260404T094701Z UID:DiagramCategories/4 DESCRIPTION:Title: Model categories in a grid\nby Valentina Zapata Castr o (University of Massachusetts Amherst) as part of Diagram categories in h omotopy theory\n\n\nAbstract\nModel categories provide a powerful framewor k for abstract homotopy theory\, but their complexity often makes them dif ficult to classify. By focusing on finite categories\, especially grids\, we gain a combinatorial setting where the problem becomes explicit. In thi s talk\, we explore model structures through weak factorization systems (W FS) on posets\, which are in one-to-one correspondence with transfer syste ms and their duals\, both introduced here. This perspective leads to a met hod for constructing model structures and a characterization theorem for f inding weak equivalence sets in posets. Our approach offers a pathway towa rds classifying model structures in a controlled setting.\n\nThis is joint work with Kristen Mazur\, Angélica Osorno\, Constanze Roitzheim\, Rekha Santhanam and Danika Van Niel.\n LOCATION:https://stable.researchseminars.org/talk/DiagramCategories/4/ END:VEVENT END:VCALENDAR