How is it proven that there are infinite intervals for the Universe (--infinity, t) and (t, + infinity) time?

Question

higher mathematics

How is it proven that there are infinite intervals for the Universe (--infinity, t) and
(t, + infinity) time?

Answer 1

Don't confuse math and physics.
In physics, there are hypotheses and proofs that are simply verifiable at the current moment, they may not be accurate, but they are working.
And mathematics is based on mathematical identities and axioms, and not on the real world.

Answer 2

Mathematics does not operate with the concept of time. From the word "absolutely". Cartesian coordinates are abstract.