Have you ever wondered why the universe is Lorentz-invariant?
In this letter, I attempt to prove that:
Cosmology+Quantum Mechanics ➞ Lorentz Symmetry
More precisely, if you require to live in a big universe, for a long time, and have a consistent effective quantum field theory (which includes gravity), then high energy processes (that, for example, happen in Large Hadron Collider), cannot see a preferred reference frame, and thus must be Lorentz-invariant.
Niayesh Afshordi 