BEGIN:VCALENDAR VERSION:2.0 PRODID:-//University of Utah Math Department//Departmental Colloquium//EN CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:Departmental Colloquium - Fall 2008 X-WR-CALDESC:Departmental Colloquium at University of Utah Mathematics Department X-WR-TIMEZONE:America/Denver BEGIN:VEVENT UID:20081002T160000-jean-francois-lafont@math.utah.edu DTSTART;TZID=America/Denver:20081002T160000 DTEND;TZID=America/Denver:20081002T170000 DTSTAMP:20260828T105759Z SUMMARY:Simplicial volume and locally symmetric spaces DESCRIPTION:Speaker: Jean-Francois Lafont\, The Ohio State University\n\nThe notion of simplicial volume was introduced by Gromov and Thurston in the early 1980's, and measures how efficiently a manifold can be "triangulated over the reals". I'll explain various results that follow from positivity of this invariant. I will also outline the proof (joint with B. Schmidt) … LOCATION:JWB 335 URL:http://math.utah.edu/research/colloquia/test/2008-fall/ END:VEVENT BEGIN:VEVENT UID:20081009T160000-jason-starr@math.utah.edu DTSTART;TZID=America/Denver:20081009T160000 DTEND;TZID=America/Denver:20081009T170000 DTSTAMP:20260828T105759Z SUMMARY:The Weak Approximation Problem DESCRIPTION:Speaker: Jason Starr\, Stony Brook\n\nGiven a system of polynomial equations in several variables and in 1 parameter, does there exist a "rational solution", i.e., a family of solutions which is a rational function (fraction of polynomials) in the parameter? Do there exist enough rational solutions to approximate every power series … LOCATION:JWB 335 URL:http://math.utah.edu/research/colloquia/test/2008-fall/ END:VEVENT BEGIN:VEVENT UID:20081113T160000-christian-reidys@math.utah.edu DTSTART;TZID=America/Denver:20081113T160000 DTEND;TZID=America/Denver:20081113T170000 DTSTAMP:20260828T105759Z SUMMARY:Tangled diagrams and beyond DESCRIPTION:Speaker: Christian Reidys\, The Center for Combinatorics at Nankai University\n\nIn this talk we develop the notion of generalized vacillating tableaux from molecular contact structures. We prove a bijection between tangled diagrams (tangles) and vacillating tableaux, allowing for exact and asymptotic enumeration. We show how tangles connect the concepts of partitions and … LOCATION:JWB 335 URL:http://math.utah.edu/research/colloquia/test/2008-fall/ END:VEVENT BEGIN:VEVENT UID:20081120T160000-j.-maurice-rojas@math.utah.edu DTSTART;TZID=America/Denver:20081120T160000 DTEND;TZID=America/Denver:20081120T170000 DTSTAMP:20260828T105759Z SUMMARY:ABCs of Real Algorithmic Geometry DESCRIPTION:Speaker: J. Maurice Rojas\, Texs A & M\n\nWe survey recent advances toward basic algorithmic questions in real algebraic geometry. In particular, we consider the two questions and their algorithmic complexity: (1) Does a system of sparse polynomial equations have a real root? (2) What is the topology of a real algebraic set defined by a set … LOCATION:JWB 335 URL:http://math.utah.edu/research/colloquia/test/2008-fall/ END:VEVENT BEGIN:VEVENT UID:20081204T160000-christopher-hacon@math.utah.edu DTSTART;TZID=America/Denver:20081204T160000 DTEND;TZID=America/Denver:20081204T170000 DTSTAMP:20260828T105759Z SUMMARY:Classification of Algebraic Varieties DESCRIPTION:Speaker: Christopher Hacon\, Utah\n\nA complex projective variety is a subset of complex projective space defined by a set of homogeneous polynomials. In this talk I will discuss recent results that describe the geometry of these varieties. The case of varieties of dimension 1, also known as Riemann surfaces, is classical. The geometry … LOCATION:JWB 335 URL:http://math.utah.edu/research/colloquia/test/2008-fall/ END:VEVENT BEGIN:VEVENT UID:20081211T160000-roy-baty@math.utah.edu DTSTART;TZID=America/Denver:20081211T160000 DTEND;TZID=America/Denver:20081211T170000 DTSTAMP:20260828T105759Z SUMMARY:Nonstandard analysis and jump conditions for shock waves DESCRIPTION:Speaker: Roy Baty\, Los Alomos\n\nNonstandard analysis is a relatively new area of mathematics in which infinitesimal numbers can be defined and manipulated rigorously like real numbers. To demonstrate the power of the subject, the problem of shock wave jump conditions is studied for a one-dimensional compressible gas. It is assumed … LOCATION:JWB 335 URL:http://math.utah.edu/research/colloquia/test/2008-fall/ END:VEVENT END:VCALENDAR