 stars and PBHs, as they would provide important information about the early Universe.</p></li>
<li><p>The next generation of gravitational wave observatories, such as the Einstein Telescope and the Cosmic Explorer, are expected to be able to detect BBHs formed from Pop III stars.</p></li>
</ul>
</section>
<section id="BBH/BNS-merger-rate-at-source-redshift-z_s-(in-small-dz)">
<h2>BBH/BNS merger rate at source redshift <span class="math notranslate nohighlight">\(z_s\)</span> (in small dz)<a class="headerli