Fast radio bursts signal high-frequency gravitational waves

Abstract

There is growing evidence for high-frequency gravitational waves (HFGWs) ranging from MHz to GHz. Several HFGW detectors have been operating for over a decade, and two GHz events have been reported recently. However, a confirmed detection might take a decade. This essay argues that unexplained observed astrophysical phenomena, like Fast Radio Bursts (FRBs), might provide indirect evidence for HFGWs. In particular, using the Gertsenshtein–Zel’dovich effect, we show that our model can explain three key features of FRBs: generate peak-flux up to [Formula: see text], naturally explain the pulse width and the coherent nature of FRBs. In short, our model offers a novel perspective on the indirection detection of HFGWs beyond current detection capabilities. Thus, transient events like FRBs are a rich source for multi-messenger astronomy.

Inverse Gertsenshtein effect as a probe of high-frequency gravitational waves

“…(i) Astrophysical and cosmological magnetic fields: magnetic fields are ubiquitous as they are observed across many scales in the Universe, from planets and stars [39][40][41] to galaxy and cluster scales [42,43]. Correspondingly, graviton-photon conversion is studied in the presence of planetary magnetospheres [44], highly magnetised objects such as neutron stars, pulsars, magnetars, and BHs [45][46][47][48][49], Milky Way magnetic fields [50] and largescale magnetic fields originating in the early Universe, i.e., primordial (cosmological) magnetic fields (PMFs) [33,51,52].…”