Light dark matter scattering in gravitational wave detectors

Abstract

We present prospects for discovering dark matter scattering in gravitational wave detectors. The focus of this work is on light, particle dark matter with masses below 1 $$\hbox {GeV}/\text {c}^{2}$$ GeV / c 2 . We investigate how a potential signal compares to typical backgrounds like thermal and quantum noise, first in a simple toy model and then using KAGRA as a realistic example. That shows that for a discovery much lighter and cooler mirrors would be needed. We also give some brief comments on space-based experiments and future atomic interferometers.

Detection Prospects of Dark Matter in Einstein Telescope

“…Thus, to optimize the SNR in this case, one needs a lighter mirror and lower temperature. This is in qualitative agreement with the toy model considered in [6]. However, lowering the mass of mirror will not be suitable for current GWs detector as it enhances the radiation pressure noise at low frequency and further limits the sensitivity of the detector.…”

Updated detection prospects for relic neutrinos using coherent scattering

“…where we have chosen the target mass to align with the 40 kg mirrors employed at LIGO [58] and the far right hand side holds true for the reference scenario outlined at the end of Section 3. The signatures of light dark matter scattering in gravitational wave detectors were later revised in [59] and found to be more akin to a series of instantaneous collisions with strain profiles peaking at frequencies not necessarily equal to the scattering frequency. As the collision frequency (4.1) is lower than the sampling rate of existing ground-based interferometers [61] and the average distance between scattered neutrinos far exceeds their wavelength, β ν {Γ " λ ν , we can treat each collision independently.…”

“…As the collision frequency (4.1) is lower than the sampling rate of existing ground-based interferometers [61] and the average distance between scattered neutrinos far exceeds their wavelength, β ν {Γ " λ ν , we can treat each collision independently. In this case, the strain profile from a single scattering event 2 is [59] hpf q "…”

“…The situation differs somewhat for space-based interferometers where the masses are in free fall, making it difficult to discuss in terms of a harmonic oscillator. Instead, we measure the amplitude spectral density (ASD) of the differential acceleration between the test mass and the spacecraft, as suggested in [59],…”

“…We further assume just a single resonance frequency, but note that an oscillator may have several, e.g the harmonics of the first violin mode in Figure3. See[59] and[60] for comprehensive reviews.…”