Abstract The most exciting future observation in cosmology will feature a monitoring of the cosmic expansion real time, unlike anything that has ever been attempted before. This campaign uncover crucial physical properties various constituents universe, and perhaps answer simpler question concerning whether or not is even accelerating. An unambiguous yes/no response to this query significantly ...

The acceleration of the cosmic expansion may be due to a new component of physical energy density or a modification of physics itself. Mapping the expansion of cosmic scales and the growth of large scale structure in tandem can provide insights to distinguish between the two origins. Using Minimal Modified Gravity (MMG)—a single parameter gravitational growth index formalism to parametrize modi...

Recent astronomical observations of distant supernovae lightcurves, [1]-[4], suggest that the expansion of the universe has recently begun to accelerate. Acceleration is created by an antigravitational repulsive stress, like that produced by a positive cosmological constant, or universal vacuum energy. It creates a rather bleak eschatological picture. An ever-expanding universe’s future appears...

We discuss the testable predictions of a phenomenological model in which the accelerated expansion of the universe is the result of the action of a non-gravitational force field, rather than the effect of a negative-pressure dark-energy fluid or a modification of general relativity. We show that in such a scenario the cosmic acceleration felt by distant standard candles like SNIa depends on the...

One of the questions in the cosmology courses is the cooling mechanism of cosmic fluid during it expansion according to classical concepts of the thermodynamics. In this short pedagogical paper, we quote the questions and give a natural approach dealing with this problem by measuring the dispersion velocity of the particles in the cosmic fluid by a comoving observer. We show that the thermal mo...

Abstract We use 47 gravitational wave sources from the Third LIGO–Virgo–Kamioka Gravitational Wave Detector Transient Catalog (GWTC–3) to estimate Hubble parameter H ( z ), including its current value, constant 0 . Each (GW) signal provides luminosity distance source, and we corresponding redshift using two methods: redshifted masses a galaxy catalog. Using binary black hole (BBH) masses, simul...

We offer a method of calculating the source term in the line-of-sight integral for cosmic microwave background anisotropies without using a truncated partial-wave expansion in the Boltzmann hierarchy. ∗Electronic address: [email protected]