Physics & Engineering Physics

Dr. Greg Gbur, professor at the University of North Carolina, Charlotte, will present, “Inverse Scattering and Invisible Objects.” Most problems in physics are “direct” problems, in which a “cause” is introduced and the “effect” of that cause is determined. Inverse problems reverse this process, attempting to deduce the “cause” from measurements of the “effect.” Inverse problems are now common in medical imaging, including CAT scans and MRIs, in which the internal structure of an object (the “cause”) is determined from the scattering and absorption of radiation (the “effect”).

We discuss some basics of inverse problems, and the challenges in solving them, in the context of diffraction tomography, the measurement of an object structure from a scattered field. We show how non-uniqueness in inverse problems is intimately connected with “invisibility,” and show how this connection can be used to design seemingly “invisible” objects.