In the quantum theory of gravityYanchilina can find an extremely simple answer to the question "What caused the Big Bang?"
The basic formula of this theory shows the relationship between the speed of light and the gravitational potential
In turn a change in the speed of light means a change in the Planck constant
If the gravitational potential is close to zero, then Planck's constant rushes to infinity.
Now let's look at the Heisenberg inequality
It turns out that if the gravitational potential is close to zero, then it rushes to infinity and the left part in the Heisenberg inequality.
That is, in the absence of a gravitational potential, quantum fluctuations become infinitely large,
which means that a Big Bang (or rather a pair of Big Bangs) is inevitable with the formation of a virtual universe-anti-Universe pair.
The process is presented as follows. First, a pair of ultra-high-energy particles is born,
then each of these particles decays. The actual moment of the Big Bang is the moment when the particle begins to decay,
from which our universe emerged.
Each particle from this pair has its own decay scheme, and their decay schemes are symmetrical.
The decay of a single particle that constitutes matter, and in the decay of the other antimatter.
This explains the baryonic asymmetry, or in simpler terms, the fact that our universe is made up of matter.
In addition, the decay formed all the elements of the periodic table at once. This explains the presence of a large number of heavy
elements in the Universe, which cannot be explained by the synthesis of heavy elements in the cores of stars.
And after some fairly long time, the universe and the anti-Universe will have to annihilate, and then everything will repeat.
Note also that this hypothesis about how the universe appeared is in contradiction with the existence of black holes. Near a black hole
even photons can't escape beyond the event horizon, and the Big Bang blew the entire universe out of the singularity.