The Arrow of Time In a Universe with a Positive Cosmological Constant Λ

Abstract

Motivated by the mounting evidence for dark energy, here we explore the consequences of a fundamental cosmological constant Λ for our universe. We show that when the gravitational entropy of a pure DeSitter state ultimately wins over matter, then the thermodynamic arrow of time in our universe must reverse in scales of order a Hubble time. We find that due to the dynamics of gravity and nonlocal entanglement, a finite size system such as a DeSitter patch with horizon size H −1 0 has a finite lifetime ∆t. This phenomenon arises from the dynamic gravitational instabilities that develop during a DeSitter epoch and turn catastrophic. A reversed arrow of time is clearly in disagreement with observations. Thus we are led to conclude: Nature forbids a fundamental Λ. Or else general relativity must be modified in the IR regime when Λ dominates the expansion of the Universe.

Initial Conditions for Defining an Arrow of Time at the Start of Inflation?

“…In particular, we wish to investigate what is brought up in [19] which we do not believe is correct. We don't believe that the cosmological constant is negative.…”

“…We will in future research use this above analysis as to critique what is done in [19] with an eye toward falsifying it. We also will tie in our treatment of this topic with a tie into the work provided in [20] which was presented as a contribution to the Frontiers in Fundamental physics 15 conference.…”