Example Problems

An object iscloakedif its presence cannot be detected by an observer using electromagnetic or other forms of imaging. In fact, the observer should not notice that cloaking is even occurring. Cloaking has a long history in science fiction, but recent developments have put the idea on a firmer mathematical and physical basis. Suppose that an observer seeks to image some bounded regionΩin space. This is to be accomplished by injecting energy intoΩfrom the outside, then observing the response: that is, the energy that comes out ofΩ. An example of this process is radar: