Yes, I have read some physicists did the math on their white boards and concluded matter can come into being on its on. Another theory. Not buying it because if the Doppler Effect is used to reverse the expansion of the Universe, it always comes down to the BiG Bang consisting of hydrogen and helium only. They still can't explain how all the other elements on the periodical table occurred.
My theory is: An unknown entity{s} threw out their dice with certain physics components/laws to set standards for their new Universe just to see what would happen.
Not much happened other than gravity(their singular most important physics) pulling the elements together into galaxies, nebulas, and individual stars. Some developed planetary systems.
After what was possibly a minute of their time, they saw our Rock evolve with growing organisms. Time to check us out...and watch through their UAP that they sent through wormholes or other means. Earth may have been just what they were hoping for in the infinite mix.