Popular thinking says that the Big Bang was the beginning of matter, dark matter, space, energy, and everything. After this event, the universe underwent a period of “cosmic inflation” in which its size increased by 10 septillion in an unimaginable fraction of a second.
But some theories suggest that the period of inflation actually occurred before what we call the Big Bang. Now, in a new study, physicists from the University of Texas (UT) at Austin have suggested that dark matter also formed in this short interval.
The research team called the new model “warm inflation via freezing” or WIFI. The model states that dark matter particles are formed from tiny interactions between radiation and particles in a warm “thermal bath” during inflation.
“What’s unique about our model is that dark matter is successfully produced during inflation,” says UT theoretical astrophysicist Kathryn Freese. In most models, anything created during inflation is later destroyed as the universe expands exponentially; so that in the end there is nothing left.”
The new model posits that dark matter particles form from tiny interactions between radiation and particles in a warm “thermal bath” during inflation.
Before the Big Bang, the entire universe is thought to have existed in a singularity. A singularity is a point of infinite density where space-time is infinitely bent. But the known laws of physics completely fail there; So some physicists suggest that instead of a singularity, there was a different period before the Big Bang.
That period could be the collapse of the previous universe, as in the “Big Bounce” model, or it could be cosmic inflation. This stage lasted only a billionth of a second, and energy was transferred to matter and light to become what we know as the Big Bang.
From there, the stage is set for the evolution of the universe according to the theory of “general relativity”. The authors of the recent study are not the first to suggest that cosmic inflation occurred before the Big Bang, and they are not even the first to suggest that dark matter was created during this period. What is new is their mechanism for how to produce these strange substances in quantities consistent with astronomical observations.
Warm inflation (which the “WI” in the new WIFI model refers to) is one existing idea that states that radiation is produced as exponential expansion occurs. This creates a kind of thermal bath that allows small but important interactions to occur.
