Related papers: Hubble Energy
If gravitons are super-strong interacting particles and the low-temperature graviton background exists, the basic cosmological conjecture about the Dopplerian nature of redshifts may be false: a full magnitude of cosmological redshift would…
Considering some modified Newtonian potentials and the Hubble law in writing the total energy of a test mass located at the edge of a flat Friedmann-Robertson-Walker universe, we obtain several modified Friedmann equations. Interestingly…
We study observational consequences of the model for dark energy proposed in [1] (Aoki et al., Phys.Rev. D97 (2018) no.4, 043517). We assume our universe has been created by bubble nucleation, and consider quantum fluctuations of an…
The description of the cosmological expansion and its possible local manifestations via treating the proper conformal transformations as a coordinate transformation from a comoving Lorentz reference frame to an uniformly accelerated one is…
It is shown that the Hubble constant can be derived from the standard luminosity function of galaxies as well as from a new luminosity function as deduced from the mass-luminosity relationship for galaxies. An analytical expression for the…
The first principles analysis of the radiation by an arbitrary source in a flat Friedmann-Robertson-Walker space-time is presented. The obtained analytical solution explicitly shows that the cosmological redshift is not of kinematic origin…
One of the most outstanding problems of the standard model of cosmology today is the problem of cosmological constant/dark energy. It corresponds to about 73 per cent of the energy content of the universe gone missing. I hereby postulate a…
Local measurements of the Hubble parameter obtained from the distance ladder at low redshift are in tension with global values inferred from cosmological standard rulers. A key role in the tension is played by the assumptions on the…
A higher value of Hubble constant has been obtained from measurements with nearby Type Ia supernovae, than that obtained at much higher redshift. With the peculiar motions of their hosts, we find that the matter content at such low redshift…
The Big Bang predicted theoretically by Friedmann could not be discovered in the 1920th, since global cosmological distances (more than 300-1000 Mpc) were not available for observations at that time. In 1927-29, Lema\^itre and Hubble…
We show that in imaginary time quantum metric fluctuations of empty space form a self-consistent de Sitter gravitational instanton that can be thought of as describing tunneling from "nothing" into de Sitter space of real time (no…
A hypothesis of curvature pressure is used to derive a static and stable cosmology with a tired-light redshift. The idea is that the high energy particles in the inter-galactic medium do not travel along geodesics because of the strong…
Physics invites the idea that space contains energy whose gravitational effect approximates that of Einstein's cosmological constant, Lambda; nowadays the concept is termed dark energy or quintessence. Physics also suggests the dark energy…
The Hubble parameter is a critical measurement in cosmology, which contains the most direct information of the cosmic expansion history. Since discrepancy is found between low redshift and high redshift estimations of Hubble constant, we…
The energy conditions of Einstein gravity (classical general relativity) are designed to extract as much information as possible from classical general relativity without enforcing a particular equation of state for the stress-energy. This…
The recent transition from decelerated to accelerated expansion can be seen as a reflection (or "bounce") in the connection variable, defined by the inverse comoving Hubble length ($b=\dot a$, on-shell). We study the quantum cosmology of…
Various results are obtained for a Friedmann-Robertson-Walker cosmology. We derive an exact equation that determines Hubble's law, clarify issues concerning the speeds of faraway objects and uncover a "tail-light angle effect" for distant…
The cosmological constant, which was introduced by Einstein a century ago to allow for a static universe, experienced a revival two decades ago under the label dark energy as a parameter to model the observed accelerated expansion of the…
Cosmological adiabatic particle creation results in the generation of irreversible entropy. The evolution of this entropy is examined in a flat Friedmann--Robertson--Walker universe at late times, using a dissipative model with a power-law…
One of the greatest challenges of science is to understand the current accelerated expansion of the Universe. In this work, we show that by considering the quantum nature of the gravitational field, its wavelength can be associated with an…