The exact properties of dark matter remain largely unknown despite the accumulating evidence. If dark matter is composed of weakly interacting massive particles, it would be accreted by the black hole in the galactic ...The exact properties of dark matter remain largely unknown despite the accumulating evidence. If dark matter is composed of weakly interacting massive particles, it would be accreted by the black hole in the galactic center and form a dense, cuspy spike.Dynamical friction from this spike may have observable effects in a binary system. We consider extreme-mass-ratio inspiral(EMRI) binaries comprising massive black holes harbored in dark matter spikes and stellar mass objects in elliptic orbits. We find that the gravitational-wave waveforms in the frequency domain can be substantially modified. In particular, we show that dark matter can suppress the characteristic strain of a gravitational wave at low frequency but enhance it at a higher domain.These effects are more dramatic as the dark matter density increases. The results indicate that the signal-to-noise ratio of EMRIs can be strongly reduced near 10^(-3)-0.3 Hz but enhanced near 1.0 Hz with a higher sensitivity, which can be probed via the future space-borne gravitational-wave(GW) detectors, LISA and TAIJI. The findings will have important impacts on the detection and parameter inference of EMRIs.展开更多
基金supported by the National Key Research and Development Program of China (Grant No. 2021YFC2201901)the National Natural Science Foundation of China (NSFC)(Grant No. 11851302)+4 种基金the Fundamental Research Funds for the Central Universities and Key Research Program of the Chinese Academy of Sciences (Grant No. XDPB15)supported in part by the National Key Research and Development Program of China(Grant No. 2020YFC2201501)the NSFC (Grant Nos. 11851302, 11851303,11690022, and 11747601)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB23030100)the NSFC Special Fund for Theoretical Physics (Grant No. 12147103)。
文摘The exact properties of dark matter remain largely unknown despite the accumulating evidence. If dark matter is composed of weakly interacting massive particles, it would be accreted by the black hole in the galactic center and form a dense, cuspy spike.Dynamical friction from this spike may have observable effects in a binary system. We consider extreme-mass-ratio inspiral(EMRI) binaries comprising massive black holes harbored in dark matter spikes and stellar mass objects in elliptic orbits. We find that the gravitational-wave waveforms in the frequency domain can be substantially modified. In particular, we show that dark matter can suppress the characteristic strain of a gravitational wave at low frequency but enhance it at a higher domain.These effects are more dramatic as the dark matter density increases. The results indicate that the signal-to-noise ratio of EMRIs can be strongly reduced near 10^(-3)-0.3 Hz but enhanced near 1.0 Hz with a higher sensitivity, which can be probed via the future space-borne gravitational-wave(GW) detectors, LISA and TAIJI. The findings will have important impacts on the detection and parameter inference of EMRIs.
