Gravitational Waves in Cold Dark Matter

Understand

We study the effects of cold dark matter on the propagation of gravitational waves of astrophysical and primordial origin.

• We show that the dominant effect of cold dark matter on gravitational waves from astrophysical sources is a small frequency dependent modification of the propagation speed of gravitational waves.
• However, the magnitude of the effect is too small to be detected in the near future.
• We furthermore show that the spectrum of primordial gravitational waves in principle contains detailed information about the properties of dark matter.