# Isaac Harris, Ph.D.

Assistant Professor

Purdue University

150 N. University Street, West Lafayette, IN 47907

Office: MATH 612

Email: iharris1107[at]gmail.com - or - harri814[at]purdue.edu

I graduated from The University of Delaware with a Ph.D. in Applied Mathematics under the advisement of Fioralba Cakoni in 2015. In August of 2018, I joined the Department of Mathematics at Purdue University as an Assistant Professor. From Summer 2015-2018 I was at Texas A&M University as a Visiting Assistant Professor continuing my research in Inverse Problems and Scattering Theory with my mentor Bill Rundell.

Here are links to my CV and Google Scholar page.

## Some Updates

- Referee, for the Journal of Computational Physics as of February 2018
- Referee, for Communications in Mathematical Sciences as of August 2017
- Referee, for Inverse Problems as of August 2017
- Referee, for the Journal of Computers and Mathematics with Applications as of June 2017
- Invited to the Theory and Numerics of Inverse Scattering Problems Workshop at Oberwolfach in Sept 2016 as a US Junior Fellow
- Invited AMS Special Section Speaker at the Joint Math Meeting, San Diego CA, January 2018
- Invited Special Section Speaker at the SIAM Annual Meeting, Portland OR, July 2018
- Invited Panelist at the NYC Regional Math Alliance Conference, Union NJ, September 2018
- Invited Speaker at the Applied Math Seminar, Kansas State University, October 2018
- Invited Special Section Speaker at the AMS Fall Central Sectional Meeting, Ann Arbor MI, October 2018
- Attending the Field of Dreams Conference, St Louis MO, November 2018
- Invited Special Section Speaker at the Canadian Mathematical Society Winter Meeting, Vancouver Canada, December 2018
- Invited Speaker at the 24th Inverse Days Conference, at Aalto University in Helsinki Finland, December 2018
- Invited Special Section Speaker at the SIAM Computational Science and Engineering Conference, Spokane WA, February 2019
- Giving a Lunch Talk here at Purdue for Math Graduate Students Friday February 15 2019 titled 'An Introduction to Qualitative Inverse Scattering'
- Invited Applied and Computational Math Seminar speaker at the IMA U Minnesota School of Mathematics,
~~April 2019~~**Postponed** - Invited Special Section Speaker at the Applied Inverse Problems Conference, Grenoble France, July 2019
- Invited Special Section Speaker at the SIAM Central States Conference, Ames IA, October 2019
- Invited Special Section Speaker at the IPMS-Conference, MALTA, May 2020

## Education

- B.A. in Mathematics, Kean University, 2010
- M.S. in Applied Mathematics, University of Delaware, 2012
- Ph.D. in Applied Mathematics, University of Delaware, 2015
- My Dissertation is titled "Non-Destructive Testing of Anisotropic Materials".

## Research

My research interests are in direct and inverse problems for PDEs, especially those arising in acoustic and electromagnetic scattering. I have been working on the inverse scattering problem of non-destructive testing for defects in complex media and parameter identification for periodic media. My research employs techniques from a multitude of areas in mathematical analysis, such as Functional analysis, Analysis of PDEs, Numerical and Asymptotic methods.

This figure is the cover image for Inverse Problems Volume 31 Number 2.

Reconstructions of circular cavities in an Anisotropic material via the factorization method.

* Research Interests:* Direct and Inverse Scattering, Transmission Eigenvalue Problems, Inverse Problems for (Fractional) Diffusion, Qualitative Reconstruction Methods, Electrical Impedance Tomography, Inverse Spectral Problems, Homogenization, and Asymptotic Analysis

## Refereed Research Papers:

**I.Harris**''Analysis of two transmission eigenvalue problems with a coated boundary condition ".*Applicable Analysis - Under Revision*(arXiv:1904.12908)**I. Harris**"Detecting an inclusion with a generalized impedance condition from electrostatic data via sampling".*Mathematical Methods in the Applied Sciences*(Accepted) (arXiv:1708.03203)**L. Hoeltgen, A. Kleefeld, I. Harris and M. Breuss**''Theoretical Foundation of the Weighted Laplace Inpainting Problem"*Applications of Mathematics,*Volume 64, No. 3, 2019 281-300 (arXiv:1801.09068)**I. Harris and A. Kleefeld**''Analysis of new direct sampling indicators for Far-field measurements''.*Inverse Problems*35 054002 (2019) (arXiv:1901.02351)**I. Harris and A. Kleefeld**"The inverse scattering problem for a conductive boundary condition and transmission eigenvalues".*Applicable Analysis*, DOI: 10.1080/00036811.2018.1504028 (arXiv:1608.07560)**F. Cakoni, I. Harris and S. Moskow**"The Imaging of Small Perturbations in an Anisotropic Media".*Computers and Mathematics with Applications*Volume 74, Issue 11, 2017 2769-2783 (arXiv:1702.06058)**L. Hoeltgen, I. Harris, A. Kleefeld and M. Breuss**"Analytic Existence and Uniqueness Results for PDE-Based Image Reconstruction with the Laplacian" Scale Space and Variational Methods in Computer Vision (2017), 66-79.*Lecture Notes in Computer Science*Volume 10302, Springer**I. Harris and S. Rome**"Near field imaging of small isotropic and extended anisotropic scatterers".*Applicable Analysis*Volume 96, No. 10, 2017 1713-1736 (arXiv:1601.02993)**O. Bondarenko I. Harris, and A. Kleefeld**"The interior transmission eigenvalue problem for an inhomogeneous media with a conductive boundary".*Applicable Analysis*Volume 96, No. 1, 2017 2-22 (arXiv:1510.01762)**F. Cakoni, H. Haddar, and I. Harri**s "Homogenization of the transmission eigenvalue problem for periodic media and application to the inverse problem".*Inverse Problems and Imaging*Volume 9, No. 4, 2015, 1025–1049 (arXiv:1410.3729)**F. Cakoni and I. Harris**"The factorization method for a defective region in an anisotropic material".*Inverse Problems*, 31 025002 (2015) (arXiv:1410.3737)**I. Harris, F. Cakoni, and J. Sun**"Transmission eigenvalues and non-destructive testing of anisotropic magnetic materials with voids".*Inverse Problems*, 30 035016 (2014) (Preprint)

## Other Publications:

**I. Harris**''Parameter identification for complex materials using Transmission Eigenvalues''.*Oberwolfach Report*, No. 45 (2016) 46-48. Extended Abstract for the workshop: Theory and Numerics of Inverse Scattering Problems**I. Harris**"Non-Destructive Testing of Anisotropic Materials".*The University of Delawar*e, Ph.D. Thesis (2015)

## Papers in Preparation:

**I. Harris and W. Rundell**"A direct method for reconstructing inclusions and boundary conditions from electrostatic data" (Under Preparation) (arXiv:1704.07479)**I. Harris and J. Rezac**''A Sparsity-Constrained Qualitative Method for Parameter Estimation''. (Under Preparation)**I. Harris D.-L. Nguyen, J. Sands, T. Truong**''On Scattering from Anisotropic Periodic Layers and Transmission Eigenvalue''. (Under Preparation-Working Title)**I.Harris**''The direct and inverse problem for the fractional heat equation with an impedance subregion". (Under Preparation-Working Title)**I.Harris**''Numerical approximation for the inverse transmission eigenvalue problem with a conductive boundary". (Under Preparation-Working Title)

## Teaching Summer 2019

This summer I am working with three Undergraduates, where they are studying the Analytical and Computational aspects of (Non-)Linear Spring Mass Systems as well as Electrical Impedance Tomography. The goal is for the students to understand the difficulties in solving some simple Inverse Problems that arise in the aforementioned areas. Some of the things that the students will explore are: Laplace Transform, Integral Equations, Fourier Series, Polynomial Interpolation and Regularization Techniques.