Stories
Slash Boxes
Comments

SoylentNews is people

posted by martyb on Sunday May 19 2019, @09:16PM   Printer-friendly
from the something-unobservable-made-of-something-unobserved,-it's-axionmatic dept.

In an article Friday on Universe Today, Paul M. Sutter, an astrophysicist at Ohio State, discusses one tantalizing possibility for explaining dark matter, which is that it may be comprised of particles called axions.

Axions are an exotic hypothetical particle invented to explain a conundrum in high energy physics having to to with [sic] charge-parity symmetry and the strong nuclear force. Like dark matter, we have not actually observed axions.

The conundrum is that by all rights the strong nuclear force should violate [CP-symmetry]. There are terms in the mathematics that very obviously break CP-symmetry, and yet we don't see any signs of symmetry breaking with the strong nuclear force in any of our experiments. So something must be going on to restore this symmetry when it ought to be broken.

The answer – or at least one potential answer – is a new kind of particle called the axion. The axion restores a certain kind of balance in the force (yes I'm aware of the Star wars reference here) so that the CP-symmetry is preserved and everyone can go about their daily lives. Of course experiments to date haven't directly revealed the existence of the axion, and there's a range of possible masses and properties that the axion could have.

Based on the relationship of galactic core objects to galaxy sizes, a team of astronomers was able to place upper bounds on axion particle mass, which will help guide future experiments.

It turns out that some of the range of possible axion properties allow that hypothetical particle to be a candidate for the dark matter.

The Dark Axions
If we let the axion be the dark matter it can generally explain all the usual dark matter observations. It can explain the rotation curves inside of galaxies. It can explain the motions of galaxies within galaxy clusters. It can be manufactured in sufficient abundance in the early Universe to fit observations of the cosmic microwave background. And so on.

Axions acting as dark matter also present a potential alternative for black holes in the center of galaxies

axions in the cores of galaxies can bundle together tightly enough to form a single massive ball that would at first blush look a lot like a supermassive black hole. It would be small, it wouldn't interact with light, and it would be incredibly massive.

He also notes that the recent imaging of Sagittarius A* does not rule out axion cores.


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 1) by khallow on Monday May 20 2019, @03:33PM (2 children)

    by khallow (3766) Subscriber Badge on Monday May 20 2019, @03:33PM (#845537) Journal

    However, the whole thing about dark matter being right is also premature.

    Nobody here is disagreeing with that.

  • (Score: 1, Redundant) by fyngyrz on Monday May 20 2019, @03:49PM (1 child)

    by fyngyrz (6567) on Monday May 20 2019, @03:49PM (#845540) Journal

    Nobody here is disagreeing with that.

    Glad you figured that out. A little late, but better late than never.

    --
    I got mood poisioning. Must have been something I hate.

    • (Score: 1) by khallow on Monday May 20 2019, @05:38PM

      by khallow (3766) Subscriber Badge on Monday May 20 2019, @05:38PM (#845562) Journal

      Nobody here is disagreeing with that.

      Glad you figured that out. A little late, but better late than never.

      Why accuse me of something I never did?