Resonant active-to-active (nu_a -> nu_a), as well as active-to-sterile (nu_a -> nu_s) neutrino oscillations can take place during the core bounce of a supernova collapse. Besides, over this phase, weak magnetism increases antineutrino mean free paths, and thus its luminosity. Because the oscillation feeds mass-energy into the target neutrino species, the large mass-squared difference between species (nu_a -> nu_s) implies a huge amount of energy to be given off as gravitational waves (L_GWs ~10^49erg/s), due to anisotropic but coherent nu flow over the oscillation length. This asymmetric nu-flux is driven by both the spin-magnetic and the universal spin-rotation coupling.
The novel contribution of this work stems from 1) the new computation of the anisotropy parameter alpha ~ 0.1–0.01, and 2) the use of the tight constraints from neutrino experiments as SNO and KamLAND, and the cosmic probe WMAP, to compute the gravitational-wave emission during neutrino oscillations in supernovae core collapse and bounce.
We show that the mass of the sterile neutrino nu_s that can be resonantly produced during the flavor conversions makes it a good candidate for dark matter as suggested by Fuller et al. (2003). The new spacetime strain thus estimated is still several orders of magnitude larger than those from nu difussion (convection and cooling) or quadrupole moments of neutron star matter. This new feature turns these bursts the more promissing supernova gravitational-wave signal that may be detected by observatories as LIGO, VIRGO, etc., for distances far out to the VIRGO cluster of galaxies.