BEGIN:VCALENDAR VERSION:2.0 PRODID:-//University of Utah Math Department//Commutative Algebra Seminar//EN CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:Commutative Algebra Seminar - Fall 2015 X-WR-CALDESC:Commutative Algebra Seminar at University of Utah Mathematics Department X-WR-TIMEZONE:America/Denver BEGIN:VEVENT UID:20150904T151000-adam-boocher@math.utah.edu DTSTART;TZID=America/Denver:20150904T151000 DTEND;TZID=America/Denver:20150904T161000 DTSTAMP:20260825T100349Z SUMMARY:On the closure of a linear space DESCRIPTION:Speaker: Adam Boocher\, University of Utah\n\nLet L in k^n be a linear subspace. If we choose coordinates, we can readily write down its defining equations as an affine variety. These coordinates in turn suggest several projective closures of L in various projective varieties. I'll discuss joint work with Federico Ardila which computes one of … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT BEGIN:VEVENT UID:20150911T151000-kazuma-shimomoto@math.utah.edu DTSTART;TZID=America/Denver:20150911T151000 DTEND;TZID=America/Denver:20150911T161000 DTSTAMP:20260825T100349Z SUMMARY:A new proof of a theorem of Cohen and Gabber in the positive characteristic case DESCRIPTION:Speaker: Kazuma Shimomoto\, Nihon University\n\nThis is joint work with Kazuhiko Kurano (Meiji University). Recently, Gabber proved a separable version of Cohen's structure theorem on complete local rings in positive characteristic. I will talk about a new proof of this theorem. Gabber used this theorem to provea refined alteration theorem. If … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT BEGIN:VEVENT UID:20150918T151000-steven-sam@math.utah.edu DTSTART;TZID=America/Denver:20150918T151000 DTEND;TZID=America/Denver:20150918T161000 DTSTAMP:20260825T100349Z SUMMARY:Commutative algebra of functor categories DESCRIPTION:Speaker: Steven Sam\, University of Wisconsin, Madison\n\nCommutative algebra can be studied in the general context of a symmetric monoidal abelian category. I will explain some joint work with Andrew Putman and Andrew Snowden in this direction on the category of functors from a category made out of sets or vector spaces to the category of modules over a … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT BEGIN:VEVENT UID:20150925T151000-jon-f.-carlson@math.utah.edu DTSTART;TZID=America/Denver:20150925T151000 DTEND;TZID=America/Denver:20150925T161000 DTSTAMP:20260825T100349Z SUMMARY:The relative stable category DESCRIPTION:Speaker: Jon F. Carlson\, University of Georgia, Athens\n\nLet G be a finite group and k an algebraically closed field of characteristic p > 0. Let H be a collection of p-subgroups of G. We investigate the relative stable category stmod_H(kG) of finitely generated modules modulo H-projective modules. Triangles in this category correspond to H-split … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT BEGIN:VEVENT UID:20151002T151000-sylvia-wiegand@math.utah.edu DTSTART;TZID=America/Denver:20151002T151000 DTEND;TZID=America/Denver:20151002T161000 DTSTAMP:20260825T100349Z SUMMARY:Building examples using power series over Noetherian rings DESCRIPTION:Speaker: Sylvia Wiegand\, University of Nebraska-Lincoln\n\nIn ongoing work with Willian Heinzer and Christel Rotthaus over the past twenty years we have been applying a construction for obtaining sometimes baffling, sometimes badly behaved, sometimes Noetherian, sometimes non-Noetherian, integral domains. This technique of interseting fields with power … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT BEGIN:VEVENT UID:20151002T151000-roger-wiegand@math.utah.edu DTSTART;TZID=America/Denver:20151002T151000 DTEND;TZID=America/Denver:20151002T161000 DTSTAMP:20260825T100349Z SUMMARY:Big projective modules over slightly non-commutative rings DESCRIPTION:Speaker: Roger Wiegand\, University of Nebraska-Lincoln\n\nLet H be an arbitrary positive normal affine semigroup (aka "Diophantine semigroup", aka "reduced finitely generated Krull semigroup"). Early in the millennium I proved that one can find a one-dimensional local domain R (commutative and Noetherian) and a finitely generated torsion-free R-module M … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT BEGIN:VEVENT UID:20151009T151000-alessandro-de-stefani@math.utah.edu DTSTART;TZID=America/Denver:20151009T151000 DTEND;TZID=America/Denver:20151009T161000 DTSTAMP:20260825T100349Z SUMMARY:F-thresholds of graded rings DESCRIPTION:Speaker: Alessandro De Stefani\, University of Virginia\n\nThe F-pure threshold, the diagonal F-threshold and the a-invariant are three numerical invariants that can be attached to graded rings of positive characteristic. Hirose, Watanabe, and Yoshida conjectured some relations between these numbers for strongly F-regular rings. We prove their conjecture … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT BEGIN:VEVENT UID:20151023T151000-hamid-hassanzadeh@math.utah.edu DTSTART;TZID=America/Denver:20151023T151000 DTEND;TZID=America/Denver:20151023T161000 DTSTAMP:20260825T100349Z SUMMARY:Annihilators of Koszul homologies DESCRIPTION:Speaker: Hamid Hassanzadeh\, University of Utah/Federal University of Rio de Janeiro\n\nIn this talk we reveal some connections between Koszul annihilators and residual intersection. After introducing the concepts, we show how sliding depth conditions provide non-trivial annihilators for Koszul homologies. To this end, we present a family of approximation complexes to determine the … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT BEGIN:VEVENT UID:20151030T151000-maral-mostafazadehfard@math.utah.edu DTSTART;TZID=America/Denver:20151030T151000 DTEND;TZID=America/Denver:20151030T161000 DTSTAMP:20260825T100349Z SUMMARY:On the singular locus of Hankel determinants and some of their degenerations DESCRIPTION:Speaker: Maral Mostafazadehfard\, University of Utah\n\nThis is an investigation of the ideal theoretic invariants of the gradient ideal of the determinant of some structural matrices, such as primary components, multiplicity, reductions and free resolution, along with a detailed study of homaloidal behavior. A homaloidal form is a homogeneous polynomial … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT BEGIN:VEVENT UID:20151106T151000-linquan-ma@math.utah.edu DTSTART;TZID=America/Denver:20151106T151000 DTEND;TZID=America/Denver:20151106T161000 DTSTAMP:20260825T100349Z SUMMARY:Lech's conjecture DESCRIPTION:Speaker: Linquan Ma\, University of Utah\n\nA long-standing conjecture of Lech states that the Hilbert-Samuel multiplicity does not drop for faithfully flat extensions of local rings. In this talk, we will prove this conjecture in dimension three, in characteristic p. LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT BEGIN:VEVENT UID:20151120T151000-gennady-lyubeznik@math.utah.edu DTSTART;TZID=America/Denver:20151120T151000 DTEND;TZID=America/Denver:20151120T161000 DTSTAMP:20260825T100349Z SUMMARY:Holonomic D-modules over formal power series DESCRIPTION:Speaker: Gennady Lyubeznik\, University of Minnesota\n\nHolonomic D-modules play an important role in commutative algebra. Their definition and proofs of their elementary properties are quite simple over polynomial rings, but considerably more complicated over formal power series. In this talk, I will present the very recent work of my student Peyman … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2015-fall/ END:VEVENT END:VCALENDAR