Resonant Spheres: Multifrequency Detectors of Gravitational Waves

TL;DR

This paper explores the use of spherical resonant detectors for gravitational waves, analyzing their multifrequency capabilities and the effects influencing their frequency response.

Contribution

It introduces a first order theoretical framework for evaluating coupled spectra and readouts in multifrequency spherical gravitational wave detectors.

Findings

Coupled spectrum and readout evaluation method developed

Identification of non-tuning influences affecting frequency splittings

Relevance of URF effects in multifrequency detector operation

Abstract

We discuss the capabilities of spherical antenn\ae as single multifrequency detectors of gravitational waves. A first order theory allows us to evaluate the coupled spectrum and the resonators readouts when the first and the second quadrupole bare sphere frequencies are simultaneously selected for layout tuning. We stress the existence of non-tuning influences in the second mode coupling causing draggs in the frequency splittings. These URF effects are relevant to a correct physical description of resonant spheres, still more if operating as multifrequency appliances like our PHCA proposal.