If something exists, the question of whether quantum mechanics could have created the something from a nothing is just the sort of arrogant question haters of religion think represent their intellect.
What causes the Casimir effect? The proximity of the plates being charged excludes certain wave lengths which in turn 'push' upon the outer surfaces of the plates?
For there to be wavelengths, time must exist. Before the 'bang' time nor space exited. Time and Space were made to exist, then events started occurring and things started to exist, even your arrogant self.
Arrogance is not involved on my part, but on your part. I EXPECT a citation because your explanation is not the explanation accepted by science. If you are saying this on your own authority, you’re mistaken. The Casimir effect is not produced by the mechanism you posit, and you won’t find any scientist in the world who agrees with you.