A physicist from the University of California, Santa Cruz, has introduced innovative theories regarding the elusive substance known as dark matter. In two recently published papers, Stefano Profumo suggests unconventional origins for dark matter, a material that plays a crucial role in the universe’s gravitational dynamics but remains undetectable by traditional means.
The first paper, released in May 2025, posits that dark matter may originate from a “mirror” universe where particles are composed of dark counterparts to known particles, such as protons and neutrons. In his second paper, published in early July 2025, Profumo explores the idea that dark matter particles could have emerged at the cosmic horizon, the boundary of the observable universe, during the rapid expansion following the Big Bang.
Profumo acknowledges the speculative nature of both theories, stating, “Both mechanisms are highly speculative, but they offer self-contained and calculable scenarios that don’t rely on conventional particle dark matter models, which are increasingly under pressure from null experimental results.”
Dark matter is a significant yet puzzling component of the cosmos. It neither emits nor blocks radiation, rendering direct detection impossible. Its existence is inferred from gravitational effects that exceed what can be accounted for by visible matter, such as galaxies and stars. While various theoretical candidates have been proposed, including massive cosmic structures and ephemeral particles, none have been confirmed through experimental evidence.
To develop his alternative theories, Profumo draws on different areas of physics. His first theory leverages quantum chromodynamics, which explains the strong force binding quarks and gluons into protons and neutrons. He theorizes that a “mirror” universe could exist alongside our own, governed by a different version of this strong force. Under specific early universe conditions, these hidden particles could cluster to form dark matter black holes, interacting with our universe solely through gravitational forces.
In the second paper, Profumo applies quantum field theory to the cosmic horizon, analogous to a black hole’s event horizon. Following the Big Bang, the universe experienced accelerated expansion. Profumo suggests that quantum fluctuations at the cosmic horizon may have led to the spontaneous creation of dark matter particles with varying masses.
Both of Profumo’s theories are founded on established scientific principles and offer potential avenues for empirical testing in future experiments. While further refinement is necessary, these proposals could enhance our understanding of the dark matter that permeates the universe.
The papers have been published in the scientific journal Physical Review D and are available for review. As researchers continue to investigate the nature of dark matter, Profumo’s work shines a light on previously unexplored possibilities in the ongoing quest to decode one of the universe’s most profound mysteries.
