A groundbreaking study by researchers at Colgate University sheds light on a new theory about the mysterious origins of dark matter.
Assistant Professor of Physics and Astronomy Cosmin Ilie and student researcher Richard Casey have expanded on a bold idea proposed by Katherine Freese and Martin Winkler from the University of Texas at Austin: that dark matter may have come from a separate event called the “Dark Big Bang.”
What is Dark Matter?
Dark matter is one of the universe’s greatest mysteries.
It makes up about 25% of the universe’s energy but cannot be seen directly because it doesn’t emit or absorb light.
While scientists haven’t detected it yet, its gravitational effects are evident in galaxies and beyond, influencing the movement of stars and the structure of the cosmos.
Dark matter also leaves its mark on the cosmic microwave background radiation, the faint afterglow of the Big Bang.
For decades, scientists believed all matter—including dark matter—originated from a single event, the Big Bang, about 13.8 billion years ago. This event marked the end of cosmic inflation, where the universe expanded rapidly and was filled with a hot plasma of particles and radiation.
In 2023, Freese and Winkler suggested a new idea: dark matter might not have emerged during the conventional Big Bang.
Instead, it could have come from a second event, the Dark Big Bang, which occurred months later. In this model, dark matter particles were created when a quantum field, connected only to the “Dark Sector” of the universe, decayed.
Ilie and Casey refined this model, exploring various ways the Dark Big Bang could fit with current experimental data. Their study, published in Physical Review D, uncovers new possibilities for how dark matter might have formed.
They also highlight one of the model’s most exciting predictions: gravitational waves produced by the Dark Big Bang. These ripples in spacetime could be detected by upcoming experiments.
Gravitational wave detectors like the International Pulsar Timing Array (IPTA) and the Square Kilometer Array (SKA) may soon provide the tools to test the Dark Big Bang theory. The 2023 discovery of background gravitational waves by the NANOGrav collaboration could even be linked to this model.
This research doesn’t just address dark matter’s origins—it offers a fresh perspective on how the universe evolved in its earliest moments. If proven, the Dark Big Bang theory would revolutionize our understanding of the cosmos, unlocking new insights into the forces that shaped the universe and its hidden components.
The search for answers continues, bringing us closer to unraveling the mysteries of dark matter and the origins of the universe itself.
Source: Colgate University.
