Astrophysics Milestones for Pulsar Timing Array Gravitational-wave Detection

<!--HTML--><div><span>All of the three established pulsar timing arrays (NANOGrav, EPTA, PPTA), along with international pulsar timing array (IPTA) have now reported strong Bayesian evidence for a common-spectrum stochastic process in their latest data sets, with broad agreement in the recovered spectral characteristics of this process. However, evidence for the quadrupolar Hellings &amp; Downs interpulsar correlations, which are characteristic of gravitational-wave signals, is not yet significant in any of these datasets. </span></div> <div><span>In this talk, I will review these results, and describe and quantify, through realistic simulations, the key milestones that pulsar timing arrays can be expected to achieve in the next few years.</span></div>