Given a polynomial map between two vector spaces over a field,
how many values can it miss? The lecture will present a number of
new results on this question. They were inspired by the work of
Daqing Wan, and obtained jointly with Michiel Kosters (Leiden).
For the first 15 minutes, we begin with Light Breakfast. Registration and sign-in. Walk-ins are welcome.
From 10:15--11:45, we will use MATLAB and the Computer Vision System Toolbox to demonstrate applications of object detection and tracking. Through interactive examples, you will see how to:
• Recognize objects using scale- and rotation-invariant features
• Use a cascade-classifier algorithm to find objects of interest
• Track objects using a point tracking algorithm
• Perform Kalman Filtering to predict the location of a moving object
• Implement a motion-based multiple object tracking system This event assumes some experience with MATLAB and Image Processing Toolbox.
From 11:45--12, Q&As with the speaker and Allyson Butler, Education Department, MathWorks.
In the last century, Geometry underwent several
substantial extensions and revisions based on
the fundamental revolutions that it lived through
in the XIXth century.
The purpose of the lecture is to discuss several
aspects of these transformations: the new
concepts that emerged from these new points
of view, the new perspectives that could be
drawn from bringing together the continuous and
discrete viewpoints, some classical problems that could
be solved, and the new interactions with other
disciplines that went along.
It includes the presentation of the views of the late Professor
Chern Shiing Shen on some of these issues.
In their attempt to mimic the proof of Fermat's Last Theorem for GL(n), Clozel, Harris, and Taylor, were led to a conjectural analogue of Ihara's lemma -- which is still open for n>2. In this talk we will revisit their conjecture from a more modern point of view, and reformulate it in terms of local Langlands in families, as currently being developed by Emerton and Helm. At the end, we hope to hint at potential applications.
Functionalized polymer membranes have a strong
affinity for solvent, imbibing it to form charge-lined networks which
serve as charge-selective ion conductions in a host of energy conversion
applications. We present a continuum model, based upon a reformulation
of the Cahn-Hilliard free energy, which incorporates solvation energy and
counter-ion
entropy to stabilize a host of network morphologies. We derive geometric
evolution for co-dimension one bilayers and co-dimension two pore
morphologies
and show that the system possesses a simple mechanism for competitive
evolution of co-existing networks through the common far-field chemical
potential.
Polynomial interpolation is well understood on the real line. In
multi-dimensional spaces, one often adopts a well established one-dimensional method
and fills up the space using certain tensor product rule. Examples
like this include full tensor construction and sparse grids construction.
This approach typically results in
fast growth of the total number of interpolation nodes and certain fixed geometrical structure of the
nodal sets. This imposes difficulties for practical applications,
where obtaining function values at a large number of nodes is
infeasible. Also, one often has function data from nodal locations that are not
by "mathematical design" and are ``unstructured''.
In this talk, we present a mathematical framework for conducting polynomial interpolation
in multiple dimensions using arbitrary set of unstructured nodes. The resulting method,
least orthogonal interpolation, is rigorous and has a straightforward numerical implementation.
It can faithfully interpolate any function data on any nodal sets, even on those that are considered
degenerate by the traditional methods. We also present a strategy to choose
``optimal'' nodes that result in robust
interpolation. The strategy is based on optimization of Lebesgue
function and has certain highly desirable mathematical properties.
Questions about the structure of sums of Cantor sets, as well as related questions on properties of convolutions of singular measures, appear in dynamical systems (due to persistent homoclinic tangencies and Newhouse phenomena), probabilities, number theory, and spectral theory. We will describe the recent results (joint with D.Damanik and B.Solomyak) that claim that under some natural technical conditions convolutions of measures of maximal entropy supported on dynamically dened Cantor sets in most cases (for almost all parameters in a one parameter family) are absolutely continuous. This provides a rigorous proof of absolute continuity of the density of states measure for the Square Fibonacci Hamiltonian in the low coupling regime, which was conjectured by physicists more than twenty years ago.
We consider discrete quasi-periodic long range operators with Liouvillean frequency. First, based on generalized Gordon type argument, we show that they can be approximated by a sequence of finite range operators which have no point spectrum for any phase. On the other hand, we show that when the potential for the dual model is small, then they can be approximated by a sequence of long range operators which have at least one eigenvalue for each phase in a set of full measure.
We prove that the resolvent set of any (possibly singular)
almost periodic Jacobi operator is characterized as the set of all
energies whose associated Jacobi cocycles induce a dominated splitting.
This extends a well-known result by Johnson for Schrödinger operators.