2012/05/15 by Jerome Martin, Jérôme Martin · 1 voice · 914 citations
Physics and Astronomy · #Cosmological constant #Cosmological constant problem #Cosmology #Cosmology and Gravitation Theories #Dark energy #Feynman diagram #Physics #Quantum Electrodynamics and Casimir Effect #Quantum field theory #Quantum mechanics #Relativity and Gravitational Theory #Theoretical physics #Vacuum energy #Zero-point energy #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1016/j.crhy.2012.04.008
published in Comptes Rendus Physique 13(6-7), 566-665 (Elsevier BV) · 89 pages, 14 figures, Accepted review article to appear in a special volume of the "Comptes Rendus de l'Academie des Sciences" about Dark Energy and Dark Matter
arxiv created 2012/05/15 · openalex publication_date 2012/07/01 · arxiv updated 2015/06/05 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
This article aims at discussing the cosmological constant problem at a pedagogical but fully technical level. We review how the vacuum energy can be regularized in flat and curved space–time and how it can be understood in terms of Feynman bubble diagrams. In particular, we show that the properly renormalized value of the zero-point energy density today (for a free theory) is in fact far from being 122 orders of magnitude larger than the critical energy density, as often quoted in the literature. We mainly consider the case of scalar fields but also treat the cases of fermions and gauge bosons which allows us to discuss the question of vacuum energy in super-symmetry. Then, we discuss how the cosmological constant can be measured in cosmology and constrained with experiments such as measurements of planet orbits in our solar system or atomic spectra. We also review why the Lamb shift and the Casimir effect seem to indicate that the quantum zero-point fluctuations are not an artifact of the quantum field theory formalism. We investigate how experiments on the universality of free fall can constrain the gravitational properties of vacuum energy and we discuss the status of the weak equivalence principle in quantum mechanics, in particular the Colella, Overhauser and Werner experiment and the quantum Galileo experiment performed with a Salecker–Wigner–Peres clock. Finally, we briefly conclude with a discussion on the solutions to the cosmological constant problem that have been proposed so far.