Scalar field ϕCDM models provide an alternative to the standard ΛCDM paradigm, while being physically better motivated. Dynamical scalar are divided into two classes: quintessence (minimally and non-minimally interacting with gravity) phantom models. These explain phenomenology of late-time dark energy. In these models, energy density pressure time-dependent functions under assumption that is described by ideal barotropic fluid model. As a consequence this, equation state parameter also...

The cosmological Mass Varying Neutrino model beyond the standard $\Lambda$CDM scenario is considered. interaction of fermionic field and scalar with inverse power law Ratra-Peebles potential via Yukawa coupling studied in detail. Depending on parameter $\alpha$ field, expansion rate universe, mass equation, sum neutrino masses, mutual influence masses value as well total density thermodynamic coupled fields at critical point are explored. values $m_\nu(a_0)\leq0.07~{\rm eV}$ calculated for...

Dark Energy models with slowly-rolling cosmological scalar field provide a popular alternative to the standard, time-independent constant model. We study simultaneous evolution of background expansion and growth in model Ratra-Peebles self-interaction potential. use recent measurements linear rate baryon acoustic oscillation peak positions constrain parameter $\alpha$ that describes steepness

We explore the scalar field quintessence freezing model of dark energy with inverse Ratra-Peebles potential. study cosmic expansion and large scale structure growth rate. use recent measurements rate baryon acoustic oscillation peak positions to constrain matter density $\Omega_\mathrm{m}$ parameter $\alpha$ that describes steepness solve jointly equations for background perturbations. The obtained theoretical results are compared observational data. perform Baysian data analysis derive...

Most dark energy models have the $\Lambda$CDM as their limit, and if future observations constrain our universe to be close Bayesian arguments about evidence fine-tuning will employed discriminate between models. Assuming a baseline model we investigate number of quintessence phantom models, study how they would perform when compared observational data, such expansion rate, angular distance, growth rate measurements, from upcoming Dark Energy Spectroscopic Instrument (DESI) survey. We sample...

Abstract— Photometric observations of the twilight sky were carried out during Leonids 1998. The obtained vertical distributions aerosol between 20 and 140 km demonstrate processes intrusion fine meteor dust its subsequent intra‐atmospheric dynamics. characteristic radii two fractions particles estimated by their sedimentation velocities. They varied within r p = 0.006–0.06 μm 19–81 limits depending on an assumed particle density ρ 0.4–4.0 g cm −3 . assumption 2.0 gave to be 0.01 30 μm, respectively.

We investigated the evolution of background expansion and growth rate matter density fluctuations in scalar field $ϕ$CDM Ratra-Peebles model. constrained model parameter $α$ $Ω_{\rm m}$ using recent measurements baryon acoustic oscillation peak position. In addition, we studied a number models order to determine whether or not it would be possible discriminate them from $Λ$CDM predicted data for future Dark Energy Spectroscopic Instrument (DESI) observations. For this purpose, carried out...

Abstract The mass-varying neutrino scenario is analyzed for three trial quintessence potentials (Ferreira-Joyce, inverse exponential, and thawing oscillating). mass generated via Yukawa coupling to the scalar field which represents dark energy. exponential oscillating are shown successfully generate masses in range m ∼ 10 -2 -10 -3 eV yield current energy density regime of late-time acceleration Universe. Depending on choice potentials, could occur two different regimes: (1) instability, (2)...

$\phi$CDM models provide an alternative to the standard $\Lambda$CDM paradigm, while being physically better motivated. These lead a time-dependent speed of sound for dark energy that is difficult replicate by $w$CDM parametrizations. We review most up-to-date status observational evidence in this paper. start with overview motivation behind these classes models, basic mathematical formalism, and different models. then present compilation recent results applying probes constraining model...

$\phi$CDM models provide an alternative to the standard $\Lambda$CDM paradigm, while being physically better motivated. These lead a time-dependent speed of sound for dark energy that is difficult replicate by $w$CDM parametrizations.
 We review most up-to-date status observational evidence in this paper.
 start with overview motivation behind these classes models, basic mathematical formalism, and different models.
 then present compilation recent results applying probes...

We studied the following scalar field ϕCDM models: ten quintessence models and seven phantom models. reconstructed these using phenomenological method developed by our group. For each potential, ranges were found: (i) model parameters; (ii) EoS (iii) initial conditions for differential equations, which describe dynamics of universe. Using MCMC analysis, we obtained constraints comparing observations expansion rate universe, angular diameter distance growth function, with corresponding...

Cosmological models that go beyond the standard Lambda Cold Dark Matter (ΛCDM) scenario, namely, scalar field ϕCDM models, are considered. The Hubble expansion rate of universe, dynamic and energetic domination dark energy, formation matter density fluctuations large-scale structure growth in these compared to spatially-flat ΛCDM model investigated.