# Thread: Can black holes be where some of the missing antimatter is stored?

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## Can black holes be where some of the missing antimatter is stored?

While Hawking radiation allows particles to escape, I have not seen a calculation that favors matter over antimatter at the boundary. If normal matter were to be favored then antimatter would trapped inside the hole. Black holes could then filter out antimatter by trapping it within the singularity. This might help somewhat in the search of its whereabouts.

2. If I understand what you are trying to solve, I think that less than a tenth of a percent of the universe is tied up in black holes, and that IF Hawking radiation is real, then only an unmeasurable fraction of that mass has had time to come back out... but the Antimatter paradox is that 50% of the universe should be antimatter... so your hypothesis that somehow Hawking Radiation only lets non-anti-matter out (for which you present no other support) seems to not solve anything, but require new physics to work.

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Sorry. I was not suggesting that all of the antimatter was in black holes. The issue is whether strong gravitational fields might alter the ratio. There is a lack of balance between the two that is quite small in favor of matter. It is not expected that this ratio would be altered by strong gravity, but that is why we do experiments. For example, a meson experiment in the micro-gravity of the space station and a duplicate experiment on Earth may prove the null result. An enhanced ratio on Earth would support a gravitational influence.

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Originally Posted by borman
... If normal matter were to be favored then antimatter would trapped inside the hole.
There is no physics or evidence that matter or antimatter is favored. Take electron and positron pairs as an example. They have identical masses. They should be created with opposite, random trajectories. They have equal chances of passing the event horizon. This Hawking radiation will be an equal mixture of electrons and positrons with the same being trapped.

5. Originally Posted by borman
Sorry. I was not suggesting that all of the antimatter was in black holes. The issue is whether strong gravitational fields might alter the ratio.
But the same objection still applies. The only places where there are gravitational fields strong enough to have a significant effect (if there were such an effect) would be around black holes. And, as noted, they form a minute amount of the mass of the universe (and influence an even smaller amount).

It is not expected that this ratio would be altered by strong gravity, but that is why we do experiments.
That suggests we should do experiments to test things we don't expect? That implies a near infinite number of speculative experiments, almost all of which would have no useful result.

It is much more efficient to use theory to predict effects to look for.

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Here is a link to the 2008 Kobayashi Nobel Lecture:
CP VIOLATION AND FLAVOUR MIXING

From the bullet points below fig.6, he suggests there is small room for new physics and that the amount of difference is too small to account for all the missing antimatter. CP Violation in the lepton sector is mentioned as a possible source.

Apparently, not too much progress has been made in the past 12 years either theoretically or experimentally to resolve the antimatter problem or it would have been announced.

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Originally Posted by borman
Here is a link to the 2008 Kobayashi Nobel Lecture:
CP VIOLATION AND FLAVOUR MIXING

From the bullet points below fig.6, he suggests there is small room for new physics and that the amount of difference is too small to account for all the missing antimatter. CP Violation in the lepton sector is mentioned as a possible source.

Apparently, not too much progress has been made in the past 12 years either theoretically or experimentally to resolve the antimatter problem or it would have been announced.
A little announced progress since 2008
In 2011, a hint of CP violation in decays of neutral D mesons was reported by the LHCb experiment at CERN using 0.6 fb−1 of Run 1 data.[8] However, the same measurement using the full 3.0 fb−1 Run 1 sample was consistent with CP symmetry.[9]

In 2013 LHCb announced discovery of CP violation in strange B meson decays.[10]

In March 2019, LHCb announced discovery of CP violation in charmed D0 decays with a deviation from zero of 5.3 standard deviations.[11]
Still not enough to resolve the matter dominance issue which leaves lepton sector CP violation as the best candidate for the remaining source. However this will be hard to test experimentally since the tests use neutrinos.

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Another question considering CPT is whether the matter-antimatter ratio could be modulated in the presence of a pseudogap. In 2002, it was discovered that pseudogaps violated time reversal symmetry. There are materials that exhibit pseudogaps which are not superconducting and some exhibit it at room temperatures. Since C, P, and CP are violated, T also has to violate symmetry to keep the CPT product from violation. Does the degree of time reversal have to be fine-tuned to keep the product CPT inviolate? If so, could the presence of a pseudogap alter the degree of time reversal violation in favor of a greater matter-antimatter ratio? The experiment to test this question can be done on Earth at one of the B meson labs.

A youtube video that discusses CPT without getting too complicated:
This Particle Breaks Time Symmetry

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Originally Posted by borman
Another question considering CPT is whether the matter-antimatter ratio could be modulated in the presence of a pseudogap. In 2002, it was discovered that pseudogaps violated time reversal symmetry.
And in 2004, 2008 and 2014 it was shown that the observations leading to this had an alternative explanation. The situation remains muddled because most of the work on this has been theoretical, and there are other explanations in the theoretical domain as well.

Originally Posted by borman
Does the degree of time reversal have to be fine-tuned to keep the product CPT inviolate?
No, because it is a binary thing for each interaction. It is either reversed or it isn't.

Originally Posted by borman
If so, could the presence of a pseudogap alter the degree of time reversal violation in favor of a greater matter-antimatter ratio? The experiment to test this question can be done on Earth at one of the B meson labs.
It would have to be very carefully designed to avoid the issues that have come up with the original experiments and theories.

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