Emergence of a Cosmological Constant in Anisotropic Fluid Cosmology

Abstract

We investigate anisotropic fluid cosmology in a situation where the spacetime metric back-reacts in a local, time-dependent way to the presence of inhomogeneities. We derive exact solutions to the Einstein field equations describing Friedmann-Lemaitre-Robertson-Walker (FLRW) large scale cosmological evolution in the presence of local inhomogeneities and time-dependent back reaction. We use our derivation to tackle the cosmological constant problem. A cosmological constant emerges by averaging the back reaction term on spatial scales of the order of $100\text{Mpc}$, at which our universe begins to appear homogeneous and isotropic. We find that the order of magnitude of the "emerged" cosmological constant agrees with astrophysical observations and is related in a natural way to baryonic matter density. Thus, there is no coincidence problem in our framework.

12 pages, no figures

References in corpus (7)

• Dynamics of dark energy
• Aspects of the cosmological "coincidence problem"
• Stability of the isotropic pressure condition
• Accelerated expansion from structure formation
• Effective Fluid Description of the Dark Universe
• Anisotropic Fluid Cosmology: an Alternative to Dark Matter?
• Galactic dynamics and long-range quantum gravity

Cited by in corpus (5)

• Cosmological coupling of nonsingular black holes
• Quasi-local masses and cosmological coupling of black holes and mimickers
• Hyperbolically symmetric versions of Lemaitre-Tolman-Bondi spacetimes
• Non-static hyperbolicallly symmetric fluids
• Effective models of non-singular quantum black holes