Primordial black holes (PBHs) were proposed more than 50 years ago as black holes possibly formed across a vast mass range in the early universe. They represent a unique probe to access the primordial universe and cosmological inflation. Furthermore, in certain mass ranges, they could comprise the entirety of the dark matter, seed supermassive black holes at high redshift, be responsible for some gravitational-wave events detected so far, and be novel gravitational-wave sources detectable with future instruments. However, detecting PBHs has proved to be extremely challenging and extensive research focused on setting a variety of constraints on the fraction of dark matter composed by these objects.

This book highlights an up-to-date, comprehensive overview on this subject, including pedagogical details on the PBH formation scenarios, cosmological evolution, astrophysical implications, connections with gravitational-wave astronomy, and critical discussion of the latest and future constraints.

At variance with all existing reviews on this subject, this book addresses graduate students and researchers not necessarily familiar with all areas of the topic, providing details on important key results rather than collecting and reviewing the latest literature.

The topic is naturally interdisciplinary and connects areas as diverse as cosmology, particle physics, gravitational-wave astronomy, and numerical simulations. To reflect this diversity, the book includes 25 contributions from key researchers working in these different areas. It provides a unique reference both to approach the topic for the first time and to learn a specific specialized sub-area.

Autorentext

The Editorial Board is formed by well-known experts in the field, with diverse and complementary expertise covering all topics of the book, and who will serve as a bridge across the different communities addressed by this project.

Christian Byrnes is professor of theoretical cosmology at the University of Sussex where he held the Royal Society University Research Fellowship from 2012 for seven years. He received his Ph.D. in 2007 from the Institute of Cosmology and Gravitation in Portsmouth and has also been a fellow in CERN and held postdoctoral positions in the German universities at Heidelberg and Bielefeld. He has researched many areas of primordial black hole and early universe physics over the last decade.

Gabriele Franciolini is a senior postdoctoral fellow at CERN, where he specializes in theoretical physics with a focus on gravitational waves, black holes, dark matter, and the early universe. He earned his Ph.D. from the University of Geneva, concentrating on the study of primordial black holes, and has since become a key contributor to major international collaborations, including the Einstein Telescope, the European Pulsar Timing Array, and LISA. Franciolini received the prestigious Buchalter Cosmology Prize in 2024 and has co-authored over 70 publications in leading scientific journals.

Tomohiro Harada is a professor of physics at Rikkyo University. He belongs to the Institute of Theoretical Physics, Department of Physics. He received his Ph.D. from Kyoto University in 1999. Right after his Ph.D., he joined the same institute as a postdoctoral fellow. Prior to moving to Rikkyo University, he held postdoctoral positions at Waseda University, Queen Mary University of London, and Kyoto University. He took up a lectureship at Rikkyo University in 2006. He was promoted to associate professor in 2008 and to full professor in 2015. He has authored or co-authored over 140 publications in leading scientific journals in the research field of general relativity, relativistic astrophysics, and cosmology. His research interests include black hole physics, gravitational waves, primordial black holes, gravitational collapse, spacetimes singularities, and dark energy.

Paolo Pani is a professor of Theoretical Physics and coordinator of the gravity theory group at Sapienza University of Rome, where he has been the principal investigator of several European projects. He received the INFN Fubini Prize and the SIGRAV Prize. He is a co-author of the book "Superradiance," of the textbook "General Relativity and its Applications," and of over 180 scientific publications on black-hole physics and gravitational-wave phenomenology, and their connections to fundamental physics.

Misao Sasaki is a professor emeritus at Kyoto University and currently a project professor at Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo. His areas of expertise are general relativity and theoretical cosmology. He is an author of the textbook "General Relativity" (in Japanese), co-author of the book "The δN Formalism in Cosmological Perturbation Theory," and has published over 300 scientific articles in peer-reviewed journals.