Nonstandard Lagrangian cosmology

We show that many independent scenarios as the ‘accelerated expansion of the universe’, ‘eternal inflation’,‘eternally oscillating universe’, ‘nonsingular oscillating universe’, and ‘collapse of an oscillating universe’ may occurwithout modifying the gravity theory or introducing scalar fields of any type. This is achieved by replacing thestandard Lagrangian in the Friedmann-Robertson-Walker spacetime model by an exponentially nonstandardLagrangian which modify the Euler-Lagrange equation although the standard variational approach is used.

کلیدواژه ها:

Nonstandard Lagrangians ، FRW cosmology ، Spacetime model