Aug 8 2019
Dark matter, which scientists believe constitute approximately 80% of the universe’s mass, is one of the most indefinable mysteries in modern physics. What is it exactly and how it came to be is unknown, but a new study conducted at Johns Hopkins University currently proposes that dark matter may have existed before the Big Bang.
The study, published on August 7th in Physical Review Letters, illustrates a new idea of how dark matter came to be and how to identify it using astronomical observations.
"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, a postdoctoral fellow in Physics and Astronomy at the Johns Hopkins University and the study's author.
While not a lot is known about its origins, astronomers have established that dark matter plays a critical role in the creation of galaxies and galaxy clusters. Though not openly observable, researchers know dark matter is present by its gravitation effects on how visible matter moves and is spread out in space.
For a long time, scientists thought that dark matter must be a surplus substance from the Big Bang. Scientists have looked for this kind of dark matter for a long time, but thus far all experimental searches have been ineffective.
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.
Tommi Tenkanen, Study Author and Postdoctoral Fellow in Physics and Astronomy, Johns Hopkins University
Using a new, basic mathematical framework, the research reveals that dark matter may have been generated before the Big Bang during an epoch called the cosmic inflation when space was expanding very quickly. The fast expansion is said to lead to plentiful production of certain kinds of particles known as scalars. Thus far, just one scalar particle has been discovered, the famed Higgs boson.
We do not know what dark matter is, but if it has anything to do with any scalar particles, it may be older than the Big Bang. With the proposed mathematical scenario, we don't have to assume new types of interactions between visible and dark matter beyond gravity, which we already know is there.
Tommi Tenkanen, Study Author and Postdoctoral Fellow in Physics and Astronomy, Johns Hopkins University
While the indication that dark matter existed prior to the Big Bang is not new, other theorists have not been able to furnish calculations that back the idea. The new research shows that scientists have always disregarded the simplest possible mathematical scenario for the origins of dark matter, he says.
The study also proposes a way to examine the origin of dark matter by exploring the signatures dark matter imparts on the distribution of matter in the universe.
While this type of dark matter is too elusive to be found in particle experiments, it can reveal its presence in astronomical observations. We will soon learn more about the origin of dark matter when the Euclid satellite is launched in 2022. It's going to be very exciting to see what it will reveal about dark matter and if its findings can be used to peak into the times before the Big Bang.
Tommi Tenkanen, Study Author and Postdoctoral Fellow in Physics and Astronomy, Johns Hopkins University
Source: http://www.jhu.edu/