Why String theory ? simple cosmological model is not sufficient for study of nature of universe
closed as not a real question by Colin K, Mark Eichenlaub, sb1, Moshe, Robert Filter Feb 16 '11 at 7:41
It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, see the FAQ.
A simple cosmological model has nothing to predict about the fate of collision of particles at high energies, or any other question about short-distance physics, for that matter. To describe the Universe not just in a broad macroscopic sketch, but also in the microscopic details, one needs a quantum theory, and string theory is the only known consistent theory that reconciles particle physics (such as gauge theories with chiral fermions) and general relativity (the latter including cosmological models).