Unless stated otherwise, colloquia are scheduled for Thursdays 4:30-5:30pm in LN 2205 with refreshments served from 4:00-4:25 pm in the Anderson Memorial Reading Room.
Here you find some directions to Binghamton University and the Department of Mathematical Sciences.
Thursday, November 15th, 2012
Speaker:
Igor Belegradek (Georgia Institute of Technology)
Title:
Open manifolds of nonpositive curvature
Time:
4:30 - 5:30 pm
Room: LN-2205
Abstract: This is a largely expository talk on known topological obstructions to nonpositive curvature. We shall first explore geometric meaning of nonpositive curvature and explain why it forces the manifold to be covered by a Euclidean space. We also discuss the uniformization of surfaces, and significance of metric completeness, after which we move to more delicate obstructions coming from harmonic map superrigidity, random groups with fixed point properties, and elementary group actions.
Thursday, November 29th, 2012
Speaker:
Sven Knoth (Institute of Mathematics and Statistics, Helmut Schmidt University Hamburg)
Title:
A Brief Introduction to Statistical Process Control (SPC)
Time:
4:30 - 5:30 pm
Room: LN-2205
Abstract: SPC assembles methods for monitoring statistical data. Useful synonyms are sequential change point detection, surveillance, control charting, continuous inspection, disorder problems, detection of abrupt changes, jump detection etc. The area was created in the 1920s by Walter Shewhart. There are many papers on theoretical aspects and on application. Dozens of software packages allow practitioners to utilize SPC on the shop floor. Quality engineers and auditors love to ask process engineers and shop floor personnel whether and how they are applying SPC procedures. During the last decade control charts, the main tools of SPC, experienced a renaissance in public health. CUSUM control charts were adopted to be applied for new data designs (keyword risk adjustment). This talk will give an overview about and some personal reflections on that field SPC.
Thursday, December 6th, 2012
Speaker:
Kirsten Eisenträger (Penn State)
Title:
Elliptic curves and Hilbert's Tenth Problem.
Time:
4:30 - 5:30 pm
Room: LN-2205
Abstract: In 1900 Hilbert presented his now famous list of 23 open problems. The tenth problem in its original form was to find an algorithm to decide, given a multivariate polynomial equation with integer coefficients, whether it has a solution over the integers. Hilbert's Tenth Problem remained open until 1970 when Matiyasevich, building on work by Davis, Putnam and Robinson, proved that no such algorithm exists, i.e. Hilbert's Tenth Problem is undecidable. Since then, analogues of this problem have been studied by asking the same question for polynomial equations with coefficients and solutions in other commutative rings. In this talk we will discuss how elliptic curves can be used to prove the undecidability of Hilbert's Tenth Problem for various rings and fields.
Thursday, March 21st, 2013
Speaker:
Robert Bieri (University of Frankfurt and Binghamton University)
Title:
Subset of the (n-1)-sphere with no balanced n-tuples.
Time:
4:30 - 5:30 pm
Room: LN-2205
Thursday, April 4th, 2013
Speaker:
Farshid Hajir (UMass Amherst)
Title:
From D=B^2-4AC to non-abelian Cohen-Lenstra heuristics.
Time:
4:30 - 5:30 pm
Room: LN-2205
Abstract: In his 1801 masterpiece, *Disquisitiones Arithmeticae*, Gauss laid the foundations not only of the arithmetic theory of quadratic forms, but also of algebraic number fields in general. Most of the conjectures he made there, about the frequency of occurrence of various groups as class groups of binary quadratic forms, are still open. But in the 1980s, Cohen and Lenstra formulated a simple heuristic which "explains" Gauss's observations in terms of the theory of abelian groups. In recent joint work with Nigel Boston and Michael Bush, we study the variation of pro-p fundamental groups, generalizing the Cohen-Lenstra heuristics to a non-abelian setting. In this expository talk for a general audience, I will sketch the outlines of this work.
Thursday, April 11th, 2013
Dean's Speaker Series in Geometry/Topology
Speaker:
Yuri Zarhin (Penn State)
Title:
One-dimensional polynomial maps, periodic orbits and multipliers.
Time:
4:30 - 5:30 pm
Room: LN-2205
Abstract: We study the map that sends a monic degree n complex polynomial f(x) without multiple roots to the collection of n values of its derivative at the roots of f(x). We give an answer to a question posed by Ju.S. Ilyashenko.
Thursday, April 25th, 2013
Dean's Speaker Series in Geometry/Topology
Speaker:
Robert Jerrard (University of Toronto)
Title:
Weak solutions of an equation describing vortex filaments.
Time:
4:30 - 5:30 pm
Room: LN-2205
Abstract: An old conjecture, dating back to the early 20th century, holds that vortex filaments in ideal fluids in certain limits can be described by a geometric evolution equation called the binormal curvature flow. Smooth solutions of the binormal curvature flow are mostly well-understood. However, it is interesting and possibly useful to study rough solutions as well, for a couple of (probably orthogonal) reasons: because non-smooth vortex filaments may occur in physical fluids, and because some rough solutions of the binormal curvature flow are conjectured to exhibit very rich, peculiar (and probably nonphysical) behavior with surprising number-theoretic properties. This talk will describe the history of some of these conjectures, which remain completely open, as well as a recent proposal for a notion of very weak solutions of the binormal curvature flow which reveals some previously unexpected stability properties.
Wednesday, May 1st, 2013 [Note unsuaul day of the week! ]
Dean's Speaker Series in Geometry/Topology
Speaker:
Allan Greenleaf (Rochester)
Title:
Is there a general theory of Fourier integral operators?.
Time:
4:40 - 5:40 pm
Room: LN-2205
Abstract: Fourier integral operators (FIOs) are fundamental tools in the analysis of linear partial differential equations. FIOs can, as in Egorov's theorem, be used to conjugate partial differential operators to normal forms, which are then easier to analyze, and they are natural objects for studying the spectral geometry of Riemannian manifolds . These early applications of FIOs have since broadened, first to linear inverse problems, such as the Radon transform and its variants, and more recently to linearizations of nonlinear inverse problems, such as in exploration seismology. However, these applications often lead to situations where the assumptions of the standard FIO calculus are violated. This talk will describe the geometry, formulated in terms of singularity theory, behind these difficulties and assess the prospects for having a satisfactory general theory.