Dark Energy as a Cosmological Consequence of Existence of the Dirac Scalar Field in Nature

Abstract

The solution of the field equations of the conformal theory of gravitation with Dirac scalar field in Cartan-Weyl spacetime at the very early Universe is obtained. In this theory dark energy (described by an effective cosmological constant) is a function of the Dirac scalar field . This solution describes the exponential decreasing of at the inflation stage and has a limit to a constant value of the dark energy at large time. This can give a way to solving the fundamental cosmological constant problem as a consequence of the fields dynamics in the early Universe.

A Clifford-gravity-based cosmology, dark matter and dark energy

“…It was shown in [23] how the action was related to a Brans-Dicke-Jordan model whose ω parameter had its critical value ω = −3/2 and leading to the observed constant vacuum energy density when the scalar field θ was scaled to a constant such that (θ o ) 2 = 1/G. Closely-related results have been obtained recently by [25], where dark energy is due to the existence of a Dirac scalar field in a conformal theory of gravitation. In this cosmological model, dark energy (described by an effective cosmological constant) is a function of a Dirac scalar field and such that there is an exponential decrease of the value of the scalar field (from the inflation stage) down to a constant limiting value at large times.…”

The Solution of the Cosmological Constant Problem: The Cosmological Constant Exponential Decrease in the Super-Early Universe

“…If we omit the terms with squares of curvature, the Lagrangian density 4-form of the Poincaré-Weyl gauge theory of gravity takes the form [20][21][22]:…”

“…According to Gliner [25,26], the cosmological constant Λ in the Einstein equations is interpreted as the energy of the hypothetical vacuum-like medium, which is currently called dark energy. The term β 2 Λ 0 in (1) describes the effective cosmological constant [20][21][22] (interpreted here as dark energy), depending on the Weyl-Dirac scalar field β (Λ 0 is the theory parameter providing the correct rate of inflation). The equality β 2 0 Λ 0 = 10 120 Λ (see [27]) should be fulfilled, where Λ is the modern value of the cosmological constant and β 0 is the value of the Weyl-Dirac scalar field at t = 0.…”

“…In [19][20][21][22], it was hypothesized that the group of symmetry of space-time at the primordial stage of the evolution of the Universe-the epoch of the Big Bang and subsequent inflation-was not the Poincaré group, but the Poincaré-Weyl group. At this stage, the rest masses of elementary particles had not yet appeared, and all interactions were carried out by massless quanta; therefore, these interactions had the property of scale invariance.…”

The Solution of the Cosmological Constant Problem: The Cosmological Constant Exponential Decrease in the Super-Early Universe

“…The proposed hypothesis is based on the assumption made by Harrison and Zel'dovich about the approximate scale invariance of the early stage of the evolution of the Universe, which underlies the calculation of the initial part of the spectrum of primary fluctuations of matter density in the early Universe (Harrison -Zel'dovich Plateau, see [22]) and have been confirmed by results of the COBE experiment for the study of the anisotropy of the brightness of the background radiation.…”