Book Description

Primordial black holes (PBH) are a promising candidate for dark matter. Because they do not interact with light and are potentially quite small, we aim to develop new observational probes that might allow us to constrain or detect them. Pulsars are extremely regular clocks and are thus quite sensitive probes of gravitational perturbation. If a PBH were captured in orbit around a pulsar, its gravitational impacts on the pulsar may lead to visible and periodic changes in the pulsar timing, providing a unique opportunity for observations. By studying three-body dynamics as a mechanism of capture, we have found equations for capture rates and ejection timescales, leading to estimates of captured populations of PBHs in arbitrary binary systems. We find that the ejection timescale for the solar system is on the scale of 5 x 105 years, which agrees with previous work. We have also analyzed the distribution of orbital parameters of these bound objects. Knowing the expected size and orbital parameters of a population of bound PBHs in any given binary system allows us to predict the visible effects in pulsar timing. If we see the effects we expect, we have further reason to believe that PBHs exist. If we do not see these effects, we can further constrain PBHs.