The scarcity of antimatter in the universe compared to matter is one of the fundamental mysteries in physics. Antimatter is essentially a counterpart to matter, with particles having the same mass but opposite charge. For example, an antielectron (positron) has the same mass as an electron but a positive charge.
According to the currently accepted theories of particle physics, matter and antimatter should have been produced in equal amounts during the early stages of the universe, such as during the Big Bang. However, for reasons that are not yet fully understood, there was an imbalance between the two. The exact mechanisms that led to this imbalance, known as baryogenesis, are still an active area of research.
The scarcity of antimatter is evident in our observations of the universe today. In cosmological terms, we see that matter dominates over antimatter. Galaxies, stars, planets, and virtually all observable celestial objects are composed of matter. There is no definitive evidence of any large-scale region of the universe that consists solely of antimatter.
One of the reasons for this imbalance could be that when matter and antimatter come into contact, they annihilate each other, releasing a tremendous amount of energy. This process is well-established in particle physics experiments. It is believed that the early universe experienced a period of rapid expansion called inflation, during which small fluctuations in the density of matter and antimatter eventually led to the dominance of matter over antimatter.
While antimatter is not abundant in the universe, it is still produced in certain astrophysical processes, such as high-energy collisions of particles or in cosmic ray interactions. Scientists continue to study antimatter and its properties to gain a better understanding of the fundamental laws of physics and the early universe.