Scientists have proposed two intriguing theories that could help explain the mysterious nature of dark matter. Physicist Stefano Profumo of the University of California, Santa Cruz, suggests that dark matter might exist in a hidden “mirror” universe or could have been generated at the edge of the observable universe during rapid expansion after the Big Bang. In the first theory, Profumo explores the idea of a shadow sector that follows many of the same physical laws as our known universe.
Inspired by quantum chromodynamics, which describes how quarks are bound inside protons and neutrons, this theory involves dark quarks and dark gluons binding together to form heavy composite particles called dark baryons. Under certain conditions in the early universe, these dark baryons could have collapsed into small, stable black hole-like objects that account for the dark matter we observe today. The second theory examines whether dark matter could be produced by the universe’s expanding “cosmic horizon.” Using principles from quantum field theory in curved spacetime, Profumo shows that a wide range of dark matter masses could result from this mechanism, depending on the temperature and duration of the expansion phase.
Dark matter mirror universe theory
This idea draws inspiration from the concept that observers near cosmic horizons, such as those of a black hole, perceive thermal radiation due to quantum effects. Both theories continue UC Santa Cruz’s tradition of integrating particle theory with cosmic-scale phenomena to tackle the mystery of dark matter.
Profumo, deputy director for theory at the Santa Cruz Institute for Particle Physics, noted that while both mechanisms are speculative, they offer self-contained scenarios that do not depend on conventional particle dark matter models, which have faced challenges from null experimental results. Profumo’s upcoming textbook, “An Introduction to Particle Dark Matter,” captures lessons from cutting-edge techniques used in dark matter research. His work remains rooted in known physics, extending well-studied theories to new frontiers.
These studies appeared in Physical Review D, the American Physical Society’s premier venue for theoretical particle physics. The search for the fundamental nature of dark matter continues, with the hope that someday we might unravel the secrets of the dark side of physics.
