Department of Mathematics Colloquium

University of Idaho

Spring 2012

Thursday,  May 3, 3:30-4:20 pm, room TLC 032

Refreshments in Brink 305 at 3:00 pm

Active exterior cloaking for the Helmholtz equation

 

Fernando Guevara Vasquez


Department of Mathematics

University of Utah



Abstract

We present a way of using active sources to hide objects from a known incident field. The active sources cancel out the incident field in a region while having a small far field. Since very little waves reach objects in the cloaked region, the scattered field is greatly diminished, making the object practically invisible. We recall how to construct such a cloak using a single and double layer potential on a surface (Green's formulas) and then show how the same effect can be achieved using a few multipolar sources that do not completely surround the cloaked region.