Dark baryon black holes

We explore a novel mechanism for dark matter production through the formation of light black holes from the collapse of dark baryons in confining SU(N) gauge theories in the large-<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>N</a:mi></a:math> limit. While glueballs and mesons cannot form black holes under physically reasonable conditions, we prove that for appropriate ranges of the confinement scale, quark masses, number of colors <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>N</c:mi></c:math>, and dark sector temperature, dark baryons can produce Planck-scale black hole relics in the early Universe. Assuming the relics are stable, the abundance of both the dark baryon black hole population directly arising at confinement and that frozen in from dark glueball and meson pair annihilation are exponentially suppressed in <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mi>N</e:mi></e:math>, leading to an upper limit <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:mi>N</g:mi><g:mo>≲</g:mo><g:mn>100</g:mn></g:math> and of a few hundred Planck units in mass for models where the black hole relics are the entirety of the dark matter. We present a detailed numerical study of the parameter space where this scenario is realized.