Study Suggests Dark Matter Existed Before the Big Bang

In a remarkable expansion of our understanding of cosmology, a recent investigation posits that dark matter may have originated prior to the Big Bang, challenging the conventional paradigm that considers the Big Bang as the definitive inception of all physical phenomena—matter, dark matter, space, and energy. Following this cataclysmic event, our Universe is believed to have experienced a phase of cosmic inflation, during which it expanded exponentially by an astonishing factor of 10 septillion in an infinitesimal fraction of time.

However, emerging theories suggest that this inflationary epoch may have transpired before what we designate as the Big Bang, a notion recently entertained by physicists at the University of Texas at Austin. Their proposal asserts that dark matter was generated amidst this transient phase.

The researchers introduce a novel framework termed warm inflation via freeze-in, or WIFI, wherein dark matter particles emerge from minute interactions between radiation and particles in a warm ‘thermal bath’ during inflation. “The distinguishing feature of our model is that dark matter is effectively produced during inflation,” remarks Katherine Freese, a theoretical astrophysicist affiliated with UT Austin.

Traditionally, it is posited that any entities formed during inflation are rendered negligible due to the exponential expansion of the Universe. Yet, the authors argue for a mechanism that allows the preservation of dark matter particles even amidst this rapid expansion.

While the Universe is thought to have existed as a singularity prior to the Big Bang—a state characterized by infinite density and a breakdown of known physical laws—some physicists advocate for an alternate epoch preceding this singularity.

The model of warm inflation stipulates that during this inflationary phase, energy dissipates into radiation, creating a thermal environment conducive to the production of dark matter through a process aptly named UV freeze-in. The team’s calculations indicate that this mechanism generates sufficient dark matter to align with current astronomical observations.

This proposition, however, does not resolve the overarching enigma surrounding dark matter. Rather, it constitutes one hypothesis among many, including notions of a separate ‘Dark Big Bang’. Upcoming investigations, particularly those focusing on the cosmic microwave background, such as CMB-S4, may offer critical insights, potentially validating the warm inflation paradigm. “If subsequent observations corroborate that warm inflation accurately embodies cosmic evolution, the implications for dark matter production as proposed in our model would be profoundly significant,” anticipates Gabriele Montefalcone, a co-author of the study, published in Physical Review Letters.