Magnification Cross Sections for the Elliptic Umbilic Caustic Surface

Abstract

We show that the asymptotic scaling of the magnification volume cross section corresponding to an elliptic umbilic caustic surface is ${\mu }^{-2.5}$ in the two-image region and ${\mu }^{-2}$ in the four-image region, where $\mu$ is the total unsigned magnification.

v2: 6 pages, 6 figures, references added, expanded discussion in Section II