Editing Physical cosmology (section)

===Other areas of inquiry===
Cosmologists also study:
* Whether [[primordial black hole]]s were formed in our universe, and what happened to them.<ref name=Kovetz2017>{{cite journal | title=Probing Primordial Black Hole Dark Matter with Gravitational Waves | last1=Kovetz | first1=Ely D. | journal=Physical Review Letters | volume=119 | issue=13 | page=131301 | year=2017 | doi=10.1103/PhysRevLett.119.131301 | pmid=29341709 | bibcode=2017PhRvL.119m1301K | arxiv=1705.09182 | s2cid=37823911 }}</ref>
* Detection of cosmic rays with energies above the [[GZK cutoff]],<ref name=Takeda1998>{{cite journal | title=Extension of the Cosmic-Ray Energy Spectrum beyond the Predicted Greisen-Zatsepin-Kuz'min Cutoff | display-authors=1 | last1=Takeda | first1=M. | last2=Hayashida | first2=N. | last3=Honda | first3=K. | last4=Inoue | first4=N. | last5=Kadota | first5=K. | last6=Kakimoto | first6=F. | last7=Kamata | first7=K. | last8=Kawaguchi | first8=S. | last9=Kawasaki | first9=Y. | last10=Kawasumi | first10=N. | last11=Kitamura | first11=H. | last12=Kusano | first12=E. | last13=Matsubara | first13=Y. | last14=Murakami | first14=K. | last15=Nagano | first15=M. | last16=Nishikawa | first16=D. | last17=Ohoka | first17=H. | last18=Sakaki | first18=N. | last19=Sasaki | first19=M. | last20=Shinozaki | first20=K. | last21=Souma | first21=N. | last22=Teshima | first22=M. | last23=Torii | first23=R. | last24=Tsushima | first24=I. | last25=Uchihori | first25=Y. | last26=Yamamoto | first26=T. | last27=Yoshida | first27=S. | last28=Yoshii | first28=H. | journal=Physical Review Letters | volume=81 | issue=6 | date=10 August 1998 | pages=1163–1166 | doi=10.1103/PhysRevLett.81.1163 | bibcode=1998PhRvL..81.1163T | arxiv=astro-ph/9807193 | s2cid=14864921 }}</ref> and whether it signals a failure of [[special relativity]] at high energies.
* The [[equivalence principle]],<ref name=Boucher2004/> whether or not Einstein's general theory of relativity is the correct theory of [[gravitation]],<ref name=Turyshev2008>{{cite journal | title=Experimental Tests of General Relativity | last1=Turyshev | first1=Slava G. | journal=[[Annual Review of Nuclear and Particle Science]] | volume=58 | issue=1 | pages=207–248 | year=2008 | doi=10.1146/annurev.nucl.58.020807.111839| doi-access=free | bibcode=2008ARNPS..58..207T | arxiv=0806.1731 | s2cid=119199160 }}</ref> and if the fundamental [[laws of physics]] are the same everywhere in the universe.<ref name=Uzan2011>{{cite journal | title=Varying Constants, Gravitation and Cosmology | last1=Uzan | first1=Jean-Philippe | journal=Living Reviews in Relativity | volume=14 | issue=1 | pages=2 | date=March 2011 | doi=10.12942/lrr-2011-2 | doi-access=free | pmid=28179829 | pmc=5256069 | bibcode=2011LRR....14....2U | arxiv=1009.5514 }}</ref>
*{{anchor|Biophysical cosmology}}'''Biophysical cosmology''': a type of physical cosmology that studies and understands [[life]] as part or an inherent part of physical cosmology. It stresses that [[Universe#Habitability|life is inherent to the universe]] and therefore [[Life#In the universe|frequent]].<ref name="v237">{{cite book | last=Dick | first=Steven J. | title=Space, Time, and Aliens | chapter=The Biophysical Cosmology: The Place of Bioastronomy in the History of Science | publisher=Springer International Publishing | publication-place=Cham | date=2020 | isbn=978-3-030-41613-3 | doi=10.1007/978-3-030-41614-0_4 | pages=53–58}}</ref>