There are testable hypothesis, but not about the extremely early universe as of yet. The energy requirements put it outside the realm of terrestrial experiment

There are testable hypothesis, but not about the extremely early universe as of yet. The energy requirements put it outside the realm of terrestrial experiments - and as of yet no one has a good simulacra of the universe prior to the big bang. While there are some theoretical white hole approaches to justify the big bang etc. These are not as of yet testable.