Related papers: A New Redshift Interpretation
An alternative model describing the dynamics of a flat Universe without cosmological constant and allowing a gradual change of c with time is proposed. New relationships of redshift vs. distance and cosmic background radiation temperature…
In two recent papers, Abramowicz et al. claim that the expansion of the Universe can be interpreted only as the expansion of space. In fact, what they really prove is that the cosmological expansion cannot be described in terms of real…
An alternative to the postulate of dark energy required to explain the accelerated expansion of the universe is to adopt an inhomogeneous cosmological model to explain the supernovae data without dark energy. We adopt a void cosmology…
A general-relativistic theory of cosmology, the dynamical variables of which are those of Hubble's, namely distances and redshifts, is presented. The theory describes the universe as having a three-phase evolution with a decelerating…
I examine the interpretation of photon redshifts in curved spacetime, as being gravitational or Doppler in origin. In Friedmann-Lema\^itre-Robertson-Walker spacetime, redshifts between comoving observers are often attributed to "expanding…
Cosmological perturbations with wavelengths smaller than Hubble radius can be handled in the context of Newtonian theory with very high accuracy. The application of this Newtonian approximation, however, is restricted to nonrelativistic…
The luminosity distance-redshift relation is one of the fundamental tools of modern cosmology. We compute the luminosity distance-redshift relation in a perturbed flat matter-dominated Universe, taking into account the presence of…
We make the hypothesis that the velocity of light and the expansion of the universe are two aspects of one single concept connecting space and time in the expanding universe. We show that solving Friedman's equations with that…
We consider a Hubble expansion law modified in the infra-red by distance-dependent terms, and attempt to enforce homogeneity upon it. As a warm-up, we re-derive the basic kinematics of a Friedman Robertson Walker universe without using…
The emergence of a highly improbable coincidence in cosmological observations speaks to a remarkably simple cosmic expansion. Compelling evidence now suggests that the Universe's gravitational horizon, coincident with the better known…
We consider light propagation in an inhomogeneous irrotational dust universe with vanishing cosmological constant, with initial conditions as in standard linear perturbation theory. A non-perturbative approach to the dynamics of such a…
The averaged term of squared vorticity is attributed to accelerated expansion. Cosmological singularity has been a consequence of excessive symmetry of flow, such as "Hubble's law". More realistic one is suggested. Exact dynamic and…
A non-singular cosmology is derived in modified gravity (MOG) with a varying gravitational coupling strength $G(t)=G_N\xi(t)$. Assuming that the curvature $k$, the cosmological constant $\Lambda$ and $\rho$ vanish at $t=0$, we obtain a…
Cosmic acceleration is explained quantitatively, as an apparent effect due to gravitational energy differences that arise in the decoupling of bound systems from the global expansion of the universe. "Dark energy" is a misidentification of…
Harrison's argument against the interpretation of the cosmological redshift as a Doppler effect is revisited, exaggerated, and discussed. The context, purpose, and limitations of the interpretations of this phenomenon are clarified.
In cosmology based on general relativity, the universe is modeled as a fluid. The transition from the Einstein field equation to its large-scale (cosmological) version is thus analogous to the transition, for a system consisting of a large…
From an observational perspective cosmology is today in excellent shape - advances in instrumentation and data processing have enabled us to study the universe in detail back to when the first galaxies formed, map the fluctuations in the…
Cosmic voids, the less dense patches of the Universe, are promising laboratories to extract cosmological information. Thanks to their unique low density character, voids are extremely sensitive to diffuse components such as neutrinos and…
We use cosmography to present constraints on the kinematics of the Universe without postulating any underlying theoretical model a priori. To this end, we use a Markov Chain Monte Carlo analysis to perform comparisons to the supernova Ia…
We explore the possibility that the entire departure of galactic rotational velocities from their luminous Newtonian expectation be cosmological in origin, and show that within the framework of conformal gravity (but not Einstein gravity…