[Kryptid (OP)]

Mirror matter is a hypothetical form of matter which is something like a "mirror image" of normal matter: https://en.wikipedia.org/wiki/Mirror_matter. It is different from antimatter.

Although it is predicted to behave in much the same manner as ordinary matter (it is attracted by gravity and has a positive energy density), it would be very difficult to detect as it interacts with normal matter only through the gravitational force (or at least very weakly through the other forces).

If mirror matter exists, then it should be expected that quantum vacuum fluctuations should contain not only virtual particles, but virtual mirror particles as well. Since a black hole should have no particular preference for matter over mirror matter, shouldn't virtual mirror particles be converted into Hawking radiation near the event horizon just as often as their normal matter counterparts?

For very large black holes, I would therefore expect half of the Hawking radiation to be made up of low frequency photons and half of low frequency mirror photons. Since only the normal photons could be detected, we should observe the black hole emitting only half of the predicted amount of radiation. Could this lack of detectable radiation then be seen as evidence for the existence of mirror matter, especially if it was exactly half of the expected value?

[evan_au]

Mirror matter is a hypothetical form of matter which is something like a "mirror image" of normal matter

It appears that Dark Matter is far more abundant than Ordinary Matter.

So if Dark Matter is Mirror Matter, then some asymmetry must have created far more Mirror Matter than Ordinary Matter. This is just like some asymmetry must have created more Ordinary Matter than AntiMatter.

If Mirror Particles have a different mass than Ordinary Particles, that could affect their rate of formation.

Super-Symmetry is another speculative theory proposed by serious physicists, where the known particles would have a partner, but with much higher mass than the particle we know. Some of these super-partners could have characteristics that would match Dark Matter. The LHC is continuing to search for these hypothetical particles.
See: https://en.wikipedia.org/wiki/Supersymmetry

I would therefore expect half of the Hawking radiation to be made up of low frequency photons and half of low frequency mirror photons.

The photon emission rate of Hawking radiation is extremely low for stellar-mass black holes, so it would be really hard to measure.

You would need a micro black hole to have a measurable photon emission rate.

In any case, I'm not volunteering to go to the black hole to do the measurements!

[jeffreyH]

Then surely you would have mirror antimatter.

[Kryptid (OP)]

Then surely you would have mirror antimatter.

I would think so, yes.

[jeffreyH]

So if there is an asymmetry between mirror matter and mirror antimatter how did this evolve? Is there more mirror matter then mirror antimatter? The wikipedia article does say the neutrinos can oscillate into mirror neutrinos. This also indicates that the weak force may be a link between matter and its mirror equivalent. In the case of leptons that is.

[jeffreyH]

I picked up on this on mirror fermions.
https://arxiv.org/abs/1211.6947

[jeffreyH]

In the matter world we have symmetries that relate to conservation laws. Yet we have an imbalance between matter and antimatter. In the mirror world it may be that mirror antimatter dominates. I am trying to brush up on neutrinos to see if this would make sense.

[jeffreyH]

This now gets interesting. Solving the solar neutrino problem shows that neutrinos must have mass to enable them to change flavour. What about a change to a mirror neutrino flavour? Detecting those would be a challenge.
https://www.dur.ac.uk/research/news/thoughtleadership/?itemno=25777