Negative Energy Cosmology and the Cosmological Constant

Abstract

It is well known that string theories naturally compactify on anti-de Sitter spaces, and yet cosmological observations show no evidence of a negative cosmological constant in the early Universe's evolution. In this letter we present two simple nonlocal modifications of the standard Friedmann cosmology that can lead to observationally viable cosmologies with an initial (negative) cosmological constant. The nonlocal operators we include are toy models for the quantum cosmological backreaction. In Model I an initial quasiperiodic oscillatory epoch is followed by inflation and a late time matter era, representing a dark matter candidate. The backreaction in Model II quickly compensates the negative cosmological term such that the Ricci curvature scalar rapidly approaches zero, and the Universe ends up in a late time radiation era.

10 pages, 4 figures

References in corpus (8)

• de Sitter Vacua in String Theory
• Generating the curvature perturbation without an inflaton
• Adiabatic CMB perturbations in pre-big bang string cosmology
• Nonlocal Cosmology
• A Simplified Quantum Gravitational Model of Inflation
• A Phenomenological Model for the Early Universe
• Primordial Density Perturbations and Reheating from Gravity
• A solution to the cosmological constant problem

Cited by in corpus (6)

• Relaxing cosmological tensions with a sign switching cosmological constant
• De Sitter Universe in Nonlocal Gravity
• Stochastic dark energy from inflationary quantum fluctuations
• Cosmology with Scalar-Euler form Coupling
• A Cyclic Universe With Varying Cosmological Constant in $f(R,T)$ gravity
• A Soliton and a Black Hole are in Gauss-Bonnet gravity. Who wins?