Does anti- matter change simultaneously to the change in matter?
I am not sure I fully understand the question. When we now produce anti-matter in the laboratory, we change energy into matter + anti-matter. So we produce, for example, a proton and an anti-proton simultaneously. This was supposed to happy also in the early Universe, so there was, immediately after the big bang, an equal amount of matter and anti-matter. We now have found that there is difference between the decay rates of matter and anti-matter, so this contributes to an imbalance of matter and anti-matter but the effects we know about are not large enough to account for the fact that the Universe is mostly matter these days.
