Accelerating universe at the end of time

Understand

We investigate whether an accelerating universe can be realized as an asymptotic late-time solution of FLRW-cosmology with multi-field multi-exponential potentials.

• Late-time cosmological solutions exhibit a universal behavior which enables us to bound the rate of time variation of the Hubble parameter.
• In string-theoretic realizations, if the dilaton remains a rolling field, our bound singles out a tension in achieving asymptotic late-time cosmic acceleration.
• Our findings go beyond previous no-go theorems in that they apply to arbitrary multi-exponential potentials and make no specific reference to vacuum or slow-roll solutions.