New Cosmological Model Proposes Dark Matter Production During Pre-Big Bang Inflation

To explain the origins of dark market, a new model of the universe has been proposed by researchers, reports Phys.org.

"Their idea is that dark matter would be produced during a infinitesimally short inflationary phase when the size of the universe quickly expanded exponentially..."


Although inflation is mostly accepted by cosmologists as part of the Big Bang picture based on some evidence (though there is meaningful dissent), the driver of inflation is still unknown... [T]o-date research has not considered the possibility that a significant [amount] of dark matter could be produced during the inflationary expansion and not be diluted away. In the paper's WIFI model — Warm Inflation via ultraviolet Freeze-In — dark matter is created through small and rare interactions with particles in a hot, energetic environment. It contains a new mechanism where this production occurs just before the Big Bang, during cosmic inflation, leading to dark matter being formed much earlier than in existing theories...

"The thing that's unique to our model is that dark matter is successfully produced during inflation," said Katherine Freese, Director of the Weinberg Institute of Theoretical Physics and the Texas Center for Cosmology and Astroparticle Physics at The University of Texas at Austin and lead author of the paper. "In most [other] models, anything that is created during inflation is then 'inflated away' by the exponential expansion of the universe, to the point where there is essentially nothing left." In this new mechanism, all the dark matter that we observe today could have been created during that brief, pre-Big Bang period of inflation. The quantum field driving inflation, the inflation, loses some of its energy to radiation, and this radiation, in turn, produces dark matter particles via the freeze-in mechanism....


The WIFI [Warm Inflation via ultraviolet Freeze-In] model cannot yet be confirmed by observations. But a key part of the scenario, warm inflation, will be tested over the next decade by the so-called cosmic microwave background experiments. Confirming warm inflation would be a significant step for the WIFI model's dark matter production scenario.


"What was before inflation? Physicists have no idea."

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