  The most important features of the proposed spherical gravitational wave
detectors are closely linked with their symmetry. Hollow spheres share this
property with solid ones, considered in the literature so far, and constitute
an interesting alternative for the realization of an omnidirectional
gravitational wave detector. In this paper we address the problem of how a
hollow elastic sphere interacts with an incoming gravitational wave and find an
analytical solution for its normal mode spectrum and response, as well as for
its energy absorption cross sections. It appears that this shape can be
designed having relatively low resonance frequencies (about 200 Hz) yet keeping
a large cross section, so its frequency range overlaps with the projected large
interferometers. We also apply the obtained results to discuss the performance
of a hollow sphere as a detector for a variety of gravitational wave signals.
