Vacuum dynamics in the Universe versus a rigid $\Lambda =$const

Abstract

In this year, in which we celebrate 100 years of the cosmological term, $\Lambda$, in Einstein's gravitational field equations, we are still facing the crucial question whether $\Lambda$ is truly a fundamental constant or a mildly evolving dynamical variable. After many theoretical attempts to understand the meaning of $\Lambda$, and in view of the enhanced accuracy of the cosmological observations, it seems now mandatory that this issue should be first settled empirically before further theoretical speculations on its ultimate nature. In this work, we summarize the situation of some of these studies. Devoted analyses made recently show that the $\Lambda =$const. hypothesis, despite being the simplest, may well not be the most favored one. The overall fit to the cosmological observables $SNIa+BAO+H(z)+LSS+CMB$ singles out the class RVM of the "running" vacuum models, in which $\Lambda =\Lambda (H)$ is an affine power-law function of the Hubble rate. It turns out that the performance of the RVM as compared to the "concordance" $\Lambda$CDM model (with $\Lambda =$const.) is much better. The evidence in support of the RVM may reach $\sim 4\sigma$ c.l., and is bolstered with Akaike and Bayesian criteria providing strong evidence in favor of the RVM option. We also address the implications of this framework on the tension between the CMB and local measurements of the current Hubble parameter.

arXiv commentPublished in Int. J. Mod. Phys. A32 (2017) 1730014. arXiv admin note: text overlap with arXiv:1705.06723

References in corpus (35)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Planck 2015 results. XIII. Cosmological parameters
• A 2.4% Determination of the Local Value of the Hubble Constant
• The trouble with $H_0$
• CDM Models with a Smooth Component
• Planck intermediate results. XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth
• Reconciling Planck with the local value of $H_0$ in extended parameter space
• Indications of a late-time interaction in the dark sector
• First evidence of running cosmic vacuum: challenging the concordance model
• Dark energy: a quantum fossil from the inflationary Universe?
• Expansion History with Decaying Vacuum: A Complete Cosmological Scenario
• Hints of dynamical vacuum energy in the expanding Universe
• Dynamical vacuum energy in the expanding Universe confronted with observations: a dedicated study
• Median statistics and the Hubble constant
• Constraints on the Coupling between Dark Energy and Dark Matter from CMB data
• The Extragalactic Distance Scale
• Hubble expansion and structure formation in the "running FLRW model" of the cosmic evolution
• The $\bar{\Lambda }CDM$ cosmology: from inflation to dark energy through running $\Lambda$
• Determining $H_0$ with Bayesian hyper-parameters
• Dark energy perturbations and cosmic coincidence
• Testing models of vacuum energy interacting with cold dark matter
• Vacuum models with a linear and a quadratic term in H: structure formation and number counts analysis
• Dynamical dark energy: scalar fields and running vacuum
• Running vacuum in the Universe and the time variation of the fundamental constants of Nature
• Nonsingular Decaying Vacuum Cosmology and Entropy Production
• Background history and cosmic perturbations for a general system of self-conserved dynamical dark energy and matter
• Thermodynamical aspects of running vacuum models
• The cosmological constant and entropy problems: mysteries of the present with profound roots in the past
• Effective growth of matter density fluctuations in the running LCDM and LXCDM models
• Median statistics estimates of Hubble and Newton's Constant
• Fundamental constants and cosmic vacuum: the micro and macro connection
• Fundamental Constants in Physics and Their Time Variation
• Consistency of the Planck CMB data and $\Lambda$CDM cosmology
• Dark matter, dark energy and the time evolution of masses in the Universe

Cited by in corpus (17)

• Cosmology Intertwined III: $f{\sigma }_8$ and $S_8$
• Seven hints that early-time new physics alone is not sufficient to solve the Hubble tension
• Constraints on the sum of the neutrino masses in dynamical dark energy models with $w(z)\ge -1$ are tighter than those obtained in $\Lambda$CDM
• Interacting dark energy with time varying equation of state and the $H_0$ tension
• A Vacuum Phase Transition Solves $H_0$ Tension
• Possible signals of vacuum dynamics in the Universe
• Constraints on the interacting vacuum -- geodesic CDM scenario
• Dynamical dark energy versus $\Lambda =$const. in light of observations
• Density perturbations for running vacuum: a successful approach to structure formation and to the ${\sigma }_8$-tension
• Relaxing the ${\sigma }_8$-tension through running vacuum in the Universe
• Dynamical systems methods and statefinder diagnostic of interacting vacuum energy models
• Latest evidence for a late time vacuum -- geodesic CDM interaction
• Nonsingular Cosmology from an Interacting Vacuum
• Growth of structures and redshift-space distortion data in scale-dependent gravity
• Yukawa Black Holes from Interacting Vacuum
• Nonsingular Black Holes From Charged Dust Collapse: A Concrete Mechanism to Evade Interior Singularities in General Relativity
• Stellar Instability from Parametric Resonance