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 - Spring 2018 X-WR-CALDESC:Commutative Algebra Seminar at University of Utah Mathematics Department X-WR-TIMEZONE:America/Denver BEGIN:VEVENT UID:20180112T143000-florian-enescu@math.utah.edu DTSTART;TZID=America/Denver:20180112T143000 DTEND;TZID=America/Denver:20180112T153000 DTSTAMP:20260824T165229Z SUMMARY:Frobenius complexity in the graded setting DESCRIPTION:Speaker: Florian Enescu\, Georgia State University\n\n LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180119T143000-hans-christian-herbig@math.utah.edu DTSTART;TZID=America/Denver:20180119T143000 DTEND;TZID=America/Denver:20180119T153000 DTSTAMP:20260824T165229Z SUMMARY:Moment map phenomenology DESCRIPTION:Speaker: Hans-Christian Herbig\, CEP, Brazil\n\nIn the study of quadratic moment maps there appears to be a dichotomy between large and small representations. In the large case the moment map exhibits some features of regularity. This enables one to make qualitative and quantitative statements about the symplectic quotients. In the talk I will … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180126T143000-steven-v-sam@math.utah.edu DTSTART;TZID=America/Denver:20180126T143000 DTEND;TZID=America/Denver:20180126T153000 DTSTAMP:20260824T165229Z SUMMARY:Special Colloquium DESCRIPTION:Speaker: Steven V Sam\, University of Wisconsin, Madison\n\n LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180216T143000-akhil-mathew@math.utah.edu DTSTART;TZID=America/Denver:20180216T143000 DTEND;TZID=America/Denver:20180216T153000 DTSTAMP:20260824T165229Z SUMMARY:Rigidity in algebraic K-theory and topological cyclic homology DESCRIPTION:Speaker: Akhil Mathew\, University of Chicago\n\nThe Gabber-Gillet-Suslin-Thomason rigidity theorem states that for a henselian pair (R, I) with p invertible on R, the mod p algebraic K-theory of R and R/I agree. We prove a generalization of this result for arbitrary henselian pairs, where the difference is measured by topological cyclic homology; … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180223T143000-josh-pollitz@math.utah.edu DTSTART;TZID=America/Denver:20180223T143000 DTEND;TZID=America/Denver:20180223T153000 DTSTAMP:20260824T165229Z SUMMARY:A characterization of complete intersections in terms of the derived category DESCRIPTION:Speaker: Josh Pollitz\, University of Nebraska, Lincoln\n\nIn 2004, Dwyer, Greenlees, and Iyengar gave a necessary condition, on each homologically finite complex, for a local ring to a be a complete intersection. The main goal of the talk is to give an outline of the proof that the converse holds. To do this, I will introduce the notion of Koszul support … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180302T143000-thomas-polstra@math.utah.edu DTSTART;TZID=America/Denver:20180302T143000 DTEND;TZID=America/Denver:20180302T153000 DTSTAMP:20260824T165229Z SUMMARY:On the nilpotence of Frobenius actions on local cohomology modules DESCRIPTION:Speaker: Thomas Polstra\, University of Utah\n\nThe Frobenius endomorphism of a local ring of prime characteristic gives rise to Frobenius actions on local cohomology modules. In this talk we will discuss interesting connections between these Frobenius actions, tight closure, and Frobenius closure. All new results presented are from joint work … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180309T143000-yuri-tschinkel@math.utah.edu DTSTART;TZID=America/Denver:20180309T143000 DTEND;TZID=America/Denver:20180309T153000 DTSTAMP:20260824T165229Z SUMMARY:Rationality and Unirationality DESCRIPTION:Speaker: Yuri Tschinkel\, NYU, Courant\n\nI will discuss cohomological obstructions to rationality, descent varieties, and unirationality questions. LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180406T143000-ozgur-esentepe@math.utah.edu DTSTART;TZID=America/Denver:20180406T143000 DTEND;TZID=America/Denver:20180406T153000 DTSTAMP:20260824T165229Z SUMMARY:Cohomology annihilators in dimension one DESCRIPTION:Speaker: Ozgur Esentepe\, University of Toronto\n\nGiven a commutative Noetherian ring R, we are interested in the cohomology annihilator ideal ca(R). This ideal consists of the ring elements which annihilate all Ext-modules Ext^n(M,N) for any finitely generated R-module M,N and sufficiently large n. It is closely related to the singularities of our … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180406T143000-pablo-solis@math.utah.edu DTSTART;TZID=America/Denver:20180406T143000 DTEND;TZID=America/Denver:20180406T153000 DTSTAMP:20260824T165229Z SUMMARY:Hunting Vector Bundles on P1 x P1 DESCRIPTION:Speaker: Pablo Solis\, Stanford University\n\nA vector bundle on a projective variety has natural cohomology if every twist has cohomology concentrated in a single degree. Such vector bundles form extremal rays in the cone of cohomology tables of vector bundles. This cone was studied by Eisenbud and Schreyer in connection with Boij-Soederberg … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180413T143000-mengyuan-zhang@math.utah.edu DTSTART;TZID=America/Denver:20180413T143000 DTEND;TZID=America/Denver:20180413T153000 DTSTAMP:20260824T165229Z SUMMARY:Curves on a smooth cubic surface in P3 DESCRIPTION:Speaker: Mengyuan Zhang\, University of California, Berkeley\n\nWe present results on the geometry and cohomology of effective divisors on a smooth cubic surface in P3. We study the linear systems using Zariski decomposition, and determine their cohomologies. Furthermore, we study the Hartshorne-Rao modules of the curves, and determine the degrees of their … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180420T143000-christopher-eur@math.utah.edu DTSTART;TZID=America/Denver:20180420T143000 DTEND;TZID=America/Denver:20180420T153000 DTSTAMP:20260824T165229Z SUMMARY:Divisors on matroids and their volumes DESCRIPTION:Speaker: Christopher Eur\, University of California, Berkeley\n\nThe classical volume polynomial in algebraic geometry measures the degrees of ample (and nef) divisors on a smooth projective variety. We introduce an analogous volume polynomial for matroids, and give a complete combinatorial formula. For a realizable matroid, we thus obtain an explicit formula for … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180427T143000-linquan-ma@math.utah.edu DTSTART;TZID=America/Denver:20180427T143000 DTEND;TZID=America/Denver:20180427T153000 DTSTAMP:20260824T165229Z SUMMARY:Perfectoid spaces DESCRIPTION:Speaker: Linquan Ma\, University of Utah\n\n LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT BEGIN:VEVENT UID:20180504T143000-kenta-sato@math.utah.edu DTSTART;TZID=America/Denver:20180504T143000 DTEND;TZID=America/Denver:20180504T153000 DTSTAMP:20260824T165229Z SUMMARY:Ascending chain condition for F-pure thresholds DESCRIPTION:Speaker: Kenta Sato\, University of Tokyo\n\nFor a germ of a variety in positive characteristic and a non-zero ideal sheaf on the variety, we can define the F-pure threshold of the ideal by using Frobenius morphisms, which measures the singularities of the pair. In this talk, I will show that the set of all F-pure thresholds on a fixed … LOCATION:LCB 222 URL:http://math.utah.edu/caseminar/2018-spring/ END:VEVENT END:VCALENDAR