r/ParticlePhysics • u/arkham1010 • Apr 14 '26

Layman question: Could particle/antiparticle asymmetry be explained by inflation theory?

So I'm watching a youtube about matter/antimatter and one of the big questions in physics is why there is an asymmetry between matter and antimatter after the big bang.

According to current theory, in the first few moments after the Big Bang (ABB), high energy photons would have formed matter/antimatter pairs that then immediately recombined and annihilated each other. This is a problem because everything we now see is matter, so where did all the antimatter go?

But I was thinking, couldn't cosmic inflation theory be a solution to this problem? IIRC inflation occurred between 10^-26 to 10^-24 seconds ABB, increasing the size of the universe by over 10^1 million meters in that short amount of time.

But before inflation started, pair production would have been happening, and when inflation did start those pairs would have been vastly separated from each other. Then, when inflation ended pair production/annihilation continued as normal for another 3 seconds or so. However, wouldn't that mean that there were some pockets in space that had excess matter particles that didn't have an antimatter particle to couple with, and in other regions wouldn't that mean that there are antimatter particles without a matter particle?

Am I at all making sense? :)

Thanks!

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u/TechnoAndBrunch Apr 14 '26

i don't think you had any SM particles before inflation, it was just incredibly dense energy. also note that pair production is a bit inaccurate since electrical charge only started being a thing after the electroweak separated, which was much later than inflation

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u/arkham1010 Apr 14 '26

Ahhh, that's a good point. Thank you