Location and Time: Minard 118 at 3:00 PM (Refreshments at 2:30 in TBD)

*Special Colloquia or Tri-College Colloquia venues and times may vary, please consult the individual listing.

Tuesday, February 11       

Teemu Saksala , NCSU

Geometric Inverse Problems Arising from Hyperbolic PDEs

Abstract: : In this talk I will survey the classical Boundary Control method, originally developed by Belishev and Kurylev, which can be used to reduce an inverse problem for a hyperbolic equation, on a complete Riemannian manifold, to a purely geometric problem involving the so-called travel time data. For each point in the manifold the travel time data contains the distance function from this point to any point in a fixed a priori known closed observation set. If the Riemannian manifold is closed then the observation set is a closure of an open and bounded set, and in the case of a manifold with boundary the observation set is an open subset of the boundary. We will survey many known uniqueness and stability results related to the travel time data.

Tuesday, February 25

*Special Tri-College Colloquium at Concordia
Talk: Integrated Science Center 301 (Refreshments: Integrated Science Center 362)

Torin Greenwood, NDSU

Title: Coloring the integers while avoiding monochromatic arithmetic progressions

Abstract: Consider coloring the positive integers either red or blue one at a time in order.  Van der Waerden's classical theorem states that no matter how you color the integers, you will eventually have k equally spaced integers all colored the same for any k.  But, how can we minimize the number of times k equally spaced integers are colored the same?  Even for k = 3, this question is unsolved.  We will discuss progress towards proving an existing conjecture by leveraging a connection to coloring the continuous interval [0,1]. Our strategy relies on identifying classes of colorings with permutations and then using mixed integer linear programming.  Joint work with Jonathan Kariv and Noah Williams.

Thursday, May 8   

Paul Hagelstein, Baylor U

Current developments in the theory of differentiation of integrals

Abstract:  TBD