Kinematical Conformal Cosmology: Fundamental Parameters from Astrophysical Observations

Abstract

We continue the presentation of an alternative cosmology based on conformal gravity, following our kinematical approach to the subject introduced in a recent paper. In line with the assumptions of our model, which proposes a closed-form expression for the cosmic scale factor R(t), we revise the Hubble and deceleration parameters and introduce modified cosmological distances, analyzing in particular the case of the luminosity distance. Our kinematical conformal cosmology is then able to explain the anomalous acceleration of the Pioneer spacecraft, as due to a local region of gravitational blueshift. From the reported data of the Pioneer anomaly, we also compute the current value of our first fundamental parameter, γ 0 = 1.94 × 10 −28 cm −1 , in line with the original estimate by P. Mannheim of this quantity. Our second fundamental parameter, δ 0 = 3.83 × 10 −5 , interpreted as the current value of a cosmological time variable, is derived from a detailed fitting of type Ia supernovae "gold-silver" data, producing Hubble plots of the same quality of those obtained by standard cosmology, but without requiring any dark matter or dark energy contribution. If further experiments will confirm the presence of an anomalous frequency blueshift in the outer region of the solar system, as described by our model, kinematical conformal cosmology might become a viable alternative to standard cosmological theories.

Wormhole geometries in fourth-order conformal Weyl gravity

“…A similar, but different approach to conformal gravity and cosmology has been proposed by one of us in a series of papers ( [21], [22], [23], [24], [25], [26]). A new model was introduced that was called kinematical conformal cosmology [21] since it was based on purely kinematic considerations without using any dynamical equation of state for the universe.…”

“…A new model was introduced that was called kinematical conformal cosmology [21] since it was based on purely kinematic considerations without using any dynamical equation of state for the universe. This model is able to account for the accelerated expansion of the universe ( [22], [26]) and may also explain the origin of some gravitational anomalies, such as the Flyby Anomaly [25].…”

Astrophysical Tests of Kinematical Conformal Cosmology in Fourth-Order Conformal Weyl Gravity

“…A similar, but different approach to conformal cosmology was proposed by the current author in a series of papers ( [14], [15], [16]) introducing a model which was called kinematical conformal cosmology [14] (KCC in the following) since it was based on purely kinematic considerations, without using any dynamical equation of state for the Universe. This model was able to account for the accelerated expansion of the Universe [15] and might also be able to explain the origin of some gravitational anomalies, such as the Pioneer Anomaly [16] and the Flyby Anomaly [17].…”

Black hole shadows in fourth-order conformal Weyl gravity

“…and were also evaluated by one of us [31,32] with a different approach, obtaining values which differ by a few orders of magnitude from those above:…”

“…Conformal gravity -or CG for short -is a natural extension of Einstein's general relativity, originally introduced by H. Weyl [27], revisited by P. Mannheim and others [28][29][30][31][32][33][34], and even considered by G. 't Hooft [35][36][37][38] as a possible key towards a complete understanding of physics at the Planck scale.…”