2006/09/01 by Laura Mersini-Houghton, Laura Mersini–Houghton, Mersini-Houghton, Laura
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Astrophysics (astro-ph) #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Space Science and Extraterrestrial Life #astro-ph #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.48550/arxiv.gr-qc/0609006
6 pages, added 1 appendix that summarizes previous results, typos fixed
openalex publication_date 2006/09/01 · arxiv created 2007/04/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
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 H0-1 has a finite lifetime Δt. 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.