Can the cosmological "constant" run? - It may run

Abstract

Using standard quantum field theory, we discuss several theoretical aspects of the possible running of the cosmological constant (CC) term in Einstein's equations. The basic motivation for the present work is to emphasize that this possibility should also be taken into account when considering dynamical models for the dark energy (DE), which are nowadays mainly focused on identifying the DE with the energy density associated to one or more ad hoc scalar fields. At the same time, we address some recent criticisms that have been published (or privately communicated to us) attempting to cast doubts on the fundamental possibility of such running. In this work, we argue that while there is no comprehensive proof of the CC running, there is no rigorous proof of the non-running either. In particular, some purported "non-running theorem" recently adduced in the literature is, in our opinion, completely insubstantial and formally incorrect. The way to the CC running is, therefore, still open and we take here the opportunity to present a pedagogical review of the present state of the art in this field, including a a brief historical account.

LaTeX, 36 pages, typos corrected. Sections 2 and 4 include our complete refutation of the criticisms from the authors of arXiv:0712.3040 [hep-th] against our previous papers on this subject

References in corpus (5)

• Effective Action of Vacuum: Semiclassical Approach
• Dark energy perturbations and cosmic coincidence
• Cosmology is not a Renormalization Group Flow
• Effect of the Trace Anomaly on the Cosmological Constant
• Renormalization-scale independence of the physical cosmological constant

Cited by in corpus (19)

• Challenges for $\Lambda$CDM: An update
• Cosmological constant and vacuum energy: old and new ideas
• On the possible running of the cosmological "constant"
• Generalizing the running vacuum energy model and comparing with the entropic-force models
• Hubble expansion and structure formation in the "running FLRW model" of the cosmic evolution
• Dark energy perturbations and cosmic coincidence
• On the Functional Renormalization Group approach for Yang-Mills fields
• Asymptotically Safe Cosmology
• Exact RG Flow in an Expanding Universe and Screening of the Cosmological Constant
• Effective Potential in Curved Space and Cut-Off Regularizations
• On the renormalization of gauge theories in curved space-time
• Constraints on dark energy models from radial baryon acoustic scale measurements
• Perturbations in the relaxation mechanism for a large cosmological constant
• Entropy In The Present And Early Universe: New Small Parameters And Dark Energy Problem
• Dark energy perturbations and a possible solution to the coincidence problem
• Deformed Quantum Field Theory, Thermodynamics at Low and High Energies, and Gravity. I
• The inhomogeneous equation of state and the speed of convergence to a small cosmological constant
• Radiative generation of metastable minima in a scalar-fermion model
• Scale-dependent gravity and covariant scale-setting