Constraints and prospects on gravitational-wave and neutrino emissions using GW150914

Abstract

Recently, the LIGO observatory reported the first direct observation of gravitational waves, with a signal consistent with a binary black hole merger. This detection triggered several follow-up searches for coincident emission in electromagnetic waves as well as neutrinos, but no such emission was found. In this article, the implications of the non-detection of counterpart neutrinos are investigated using general arguments. The results are interpreted with a parameter denoting the energy emitted in neutrinos relative to the energy emitted in gravitational waves. The bound on this parameter from the diffuse astrophysical neutrino flux detected by the IceCube Neutrino Observatory is discussed. It is found that, currently, the non-detection of counterpart neutrinos puts a bound comparable to the one from the diffuse astrophysical neutrino flux. This bound is then used to constrain the amount of matter in the black hole binary environment. Finally, the sensitivity to this parameter in future gravitational wave observation runs is investigated. It is shown how the detection of one or more neutrinos from a single merger would strongly constrain the source population and evolution.

Coherent radio emission from the electron beam sudden appearance

“…To understand transition radiation, we have to investigate the derivative dt /dt, given by the relation between the emission time as function of the observer time t (t). Following [20], an example of this relation is given in Fig. 1.…”

“…This immediately leads to the question: How can we properly describe transition radiation? Following the approach given in [20], taking the limit to the boundary from both sides, for a single electron, one obtains,…”

“…This formalism closely follows the modeling of coherent transition radiation and sudden appearance emission outlined in Sec. 2, described both macroscopically in [20], and microscopically in [21]. Simulations are performed using the individual particle trajectories obtained from GEANT4 simulations [25], after which the radio emission from the individual tracks is obtained using the ZHS algorithm [26].…”

“…Simulations are performed using the individual particle trajectories obtained from GEANT4 simulations [25], after which the radio emission from the individual tracks is obtained using the ZHS algorithm [26]. These simulations have been cross-checked with the macroscopic approach given in [20].…”

“…As such, the agreement of the obtained data with simulation provides confidence in the understanding of the coherent transition radiation as predicted for the in-nature process of a high-energy cosmic-ray or neutrino induced particle cascade traversing different media. Indeed, as shown recently, a detectable radio signal is expected as an air shower is absorbed by the ground [19] and for neutrino induced cascades traversing the ground to air boundary [20,21]. After reviewing the mechanism of coherent transition radiation in Section II we describe the four concerned experiments and the test beam setup in Section III.…”