UC Santa Cruz physicist Stefano Profumo has put forth two novel theories in 2025 that present new perspectives on the formation of dark matter, the invisible substance believed to constitute roughly 85% of the universe's mass. These hypotheses, which have been detailed in scientific publications such as Physical Review D, aim to illuminate the origins of this enigmatic cosmic component. Profumo's "Mirror Universe Theory" suggests the existence of a parallel reality with its own unique particles and forces, a "dark sector" where dark quarks and gluons could form dark baryons. Under the extreme conditions of the early universe, these dark baryons might have collapsed gravitationally into microscopic black holes, slightly heavier than the Planck mass, interacting primarily through gravity and thus remaining undetectable by conventional means, yet their gravitational influence could explain observed dark matter.
The second theory, the "Cosmic Horizon Radiation Theory," posits that dark matter particles originated from quantum radiation processes at the boundary of the observable universe. During the universe's rapid expansion post-Big Bang, quantum effects at this cosmic horizon could have generated the particles that make up dark matter, drawing a parallel to Hawking radiation near a black hole's event horizon. Both theories are rooted in established scientific principles and mathematical frameworks, moving beyond traditional particle dark matter models that have encountered challenges due to null experimental results. These new concepts offer testable scenarios that could significantly alter our understanding of the universe's composition and fundamental forces, joining existing explanations like WIMPs and axions in the ongoing scientific endeavor to solve the dark matter mystery. The inherent difficulty in directly detecting dark matter stems from its minimal interaction with ordinary matter and radiation, primarily interacting only via gravity, making laboratory detection exceptionally challenging. The wide range of theoretical masses for dark matter particles further complicates these detection efforts, but Profumo's work provides new avenues for exploration in this critical area of cosmology.