Consider a simply-connected Riemann surface represented by a Speiser graph. Nevanlinna asked if the type of the surface is determined by the mean excess of the graph: whether mean excess zero implies ...

Slowness surface for bulk wave propagation in anisotropic media can be divided into concave, saddle and convex regions by the parabolic lines. When a parabolic line crosses a symmetry plane, it leaves ...

A parabolic antenna is a simple enough device, a curved reflector designed to focus all the radiation from the direction it’s pointed into a waveguide or antenna at its feedpoint. They’re easy enough ...

Buddy Martin works for Steward Observatory, part of the University of Arizona. He receives funding from the Giant Magellan Telescope Organization. The University of Arizona is a partner in the Giant ...