21 minutes ago, NortonH said:

Correct. And if we know N and we assume (IF!) that the leftover matter is the result of a chance imbalance after a binary matter/antimatter producing process then the most likely estimate of the original number of particles in the universe is N^2. We know what N is hence we know what N^2 is hence we know how many we expect to have been annihilated (N^2-N) and this gives us an estimate of how much non-matter energy should be out there. It does not seem to be there.

You seem to have this backwards. We know the current energy density, we know the current matter density. From this we know the amount of matter relative to energy. The energy corresponds to potential matter-antimatter pairs in the early universe and therefore we know the amount of matter left over relative to the total amount of matter-antimatter pairs. (It is roughly one billionth.)

Summary here: https://home.cern/topics/antimatter/matter-antimatter-asymmetry-problem

More detail here:https://en.wikipedia.org/wiki/Baryogenesis

Edited February 28, 20187 yr by Strange

There is a detailed article about the current status of the ALPHA project at CERN to measure the properties of anti-hydrogen: http://cerncourier.com/cws/article/cern/71088