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bystander
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by bystander » Tue Aug 13, 2019 3:53 pm
Dark Matter May Be Older Than the Big Bang
Johns Hopkins University | 2019 Aug 08
Dark matter, which researchers believe make up about 80% of the universe’s mass, is one of the most elusive mysteries in modern physics. What exactly it is and how it came to be is a mystery, but a new Johns Hopkins University study now suggests that dark matter may have existed before the Big Bang. ...
“The study revealed a new connection between particle physics and astronomy. If dark matter consists of new particles that were born before the Big Bang, they affect the way galaxies are distributed in the sky in a unique way. This connection may be used to reveal their identity and make conclusions about the times before the Big Bang too,” says Tommi Tenkanen ...
For a long time, researchers believed that dark matter must be a leftover substance from the Big Bang. Researchers have long sought this kind of dark matter, but so far all experimental searches have been unsuccessful.
“If dark matter were truly a remnant of the Big Bang, then in many cases researchers should have seen a direct signal of dark matter in different particle physics experiments already,” says Tenkanen.
Using a new, simple mathematical framework, the study shows that dark matter may have been produced before the Big Bang during an era known as the cosmic inflation when space was expanding very rapidly. The rapid expansion is believed to lead to copious production of certain types of particles called scalars. So far, only one scalar particle has been discovered, the famous Higgs boson. ...
Dark Matter from Scalar Field Fluctuations ~ Tommi Tenkanen
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bystander
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by bystander » Tue Aug 13, 2019 4:02 pm
This article seems to suggest that
cosmic inflation occurred before the
big bang. It has always been my understanding that it was the time immediately following the big bang. I'm not sure how that impacts this study and its assertion that dark matter may be
scalar particles.
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
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rstevenson
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by rstevenson » Wed Aug 14, 2019 11:04 am
bystander wrote: ↑Tue Aug 13, 2019 4:02 pm
This article seems to suggest that
cosmic inflation occurred before the
big bang. It has always been my understanding that it was the time immediately following the big bang. I'm not sure how that impacts this study and its assertion that dark matter may be
scalar particles.
I think the article writer must have slept through that class in Physics. Here, from that Wikipedia article on Inflation, is the short answer...
In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from 10^−36 seconds after the conjectured Big Bang singularity to some time between 10^−33 and 10^−32 seconds after the singularity.
I haven't read the linked paper yet, but it would surely be Big News if it happens to mention in passing that inflation preceeded the big bang.
Rob
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bystander
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by bystander » Wed Aug 14, 2019 1:45 pm
rstevenson wrote: ↑Wed Aug 14, 2019 11:04 am
I haven't read the linked paper yet, but it would surely be Big News if it happens to mention in passing that inflation preceeded the big bang.
Here's the abstract
(emphasis mine):
T Tenkanen wrote:
Dark matter (DM) may have its origin in a pre-Big Bang epoch, the cosmic inflation. Here, we consider for the first time a broad class of scenarios where a massive free scalar field unavoidably reaches an equilibrium between its classical and quantum dynamics in a characteristic time scale during inflation and sources the DM density. The study gives the abundance and perturbation spectrum of any DM component sourced by the scalar field. We show that this class of scenarios generically predicts enhanced structure formation, allowing one test models where DM interacts with matter only gravitationally.
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rstevenson
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by rstevenson » Fri Aug 23, 2019 1:10 pm
Thanks Bystander. I'll have to go and read the paper now -- though I'll have difficulty parsing that dense form of English they're using.
Just found this (my emphasis)...
I'm curious about that phrase "by this definition". Makes it all sound a bit far out and not yet part of the Received Wisdom. But that's what makes bleeding edge physics interesting!
Rob