22 research outputs found
Families of spherical caps: spectra and ray limit
We consider a family of surfaces of revolution ranging between a disc and a
hemisphere, that is spherical caps. For this family, we study the spectral
density in the ray limit and arrive at a trace formula with geodesic polygons
describing the spectral fluctuations. When the caps approach the hemisphere the
spectrum becomes equally spaced and highly degenerate whereas the derived trace
formula breaks down. We discuss its divergence and also derive a different
trace formula for this hemispherical case. We next turn to perturbative
corrections in the wave number where the work in the literature is done for
either flat domains or curved without boundaries. In the present case, we
calculate the leading correction explicitly and incorporate it into the
semiclassical expression for the fluctuating part of the spectral density. To
the best of our knowledge, this is the first calculation of such perturbative
corrections in the case of curvature and boundary.Comment: 28 pages, 7 figure