Inverse Problems Seminar
The informal biweekly seminar will be meeting on Wednesdays from noon till
1pm in Blocker Rm. 627. It will be devoted to discussing mathematical
and statistical issues of inverse problems.
Image: An example of a CT head scan (courtesy of Wikipedia).

Date Time 
Location  Speaker 
Title – click for abstract 

11/01 Noon 
BLOC 628 
Dr. Vitaly Katsnelson Rice University, Applied Math DEpartment 
Reconstruction of a piecewise smooth wave speed from exterior measurements
We will discuss how to reconstruct a piecewise smooth wave speed inside a domain D with boundary using only measurements taken outside of D; such measurements are akin to having a hyperbolic NeumanntoDirichlet map as one's given data. The main obstacle is the internal multiple scattering occurring within D due to the interfaces. We will show how to control and eliminate these internal multiples to eventually reconstruct the location of the interfaces and the wave speed itself. Our methods work for the local inverse problem as well. Numerical simulations will also be presented. 

12/01 1:50pm 
BLOC 628 
Mahmood Ettehad Texas A&M University 
Network graph reconstruction from path correlations (Joint with Math Physics and Harmonic Analysis seminar)) 

12/06 Noon 
BLOC 628 
Dr. Matthew Lewis UT Southwest Medical Center, Radiology Department 
Secrets of Spectral Computed Tomography
In the past ten years, all three major vendors of clinical CT have released different kinds of CT systems that exploit the energydependence of Xray attenuation. In this talk, I will discuss the dimensionality of Xray contrast and how these different CT systems work. Examples of artifacts of unknown origin will be presented and related to model nonlinearities. Model errors due to Kedges will also be presented, with a question to applied mathematicians: how can we exploit these singularities in novel ways? Lastly, I will conclude with a discussion of next generation photoncounting spectral CT. 
Please send inquiries and suggestions to
Peter Kuchment