Related papers: Coupling constant constraints in a nonminimally co…
We demonstrate that the latest constraints on inflationary observables, namely the tensor-to-scalar ratio $r$ and the scalar spectral index $n_{_S}$, from the Cosmic Background Radiation (CMB) observations are already strong enough to rule…
We perform a combined perturbation and observational investigation of the scenario of non-minimal derivative coupling between a scalar field and curvature. First we extract the necessary condition that ensures the absence of instabilities,…
We investigate the imprints of the Generalized Uncertainty Principle on cosmological scales by using redshift-space distortion measurements in combination with background cosmological data to determine constraints on the deformation…
The spectrum and statistics of the cosmic microwave background radiation (CMBR) are investigated under the hypothesis that scale invariance of the primordial density fluctuations should be promoted to full conformal invariance. As in the…
We study observational constraints on the non-metricity $f(Q)$-gravity which reproduces an exact $\Lambda$CDM background expansion history while modifying the evolution of linear perturbations. To this purpose we use Cosmic Microwave…
In this paper, we use a set of observational $H(z)$ data (OHD) to constrain the $\Lambda$CDM cosmology. This data set can be derived from the differential ages of the passively evolving galaxies. Meanwhile, the $\mathcal {A}$-parameter,…
We study the use of type Ia supernovae (SNe Ia) in the context of scalar-tensor theories of gravity, taking as a working example induced gravity, equivalent to Jordan-Brans-Dicke theory. Winking at accurate and precision cosmology, we test…
The coupled dark energy model provides a possible approach to mitigate the coincidence problem of cosmological standard model. Here, the coupling term is assumed as $\bar{Q}=3H\xi_x\bar{\rho}_x$, which is related to the interaction rate and…
The Cosmic Microwave Background anisotropies provide a unique opportunity to constrain simultaneous variations of the fine-structure constant $\alpha$ and Newton's gravitational constant $G$. Those correlated variations are possible in a…
We study the parameterized post-Newtonian approximation in teleparallel model of gravity with a scalar field. The scalar field is non-minimally coupled to the scalar torsion as well as to the boundary term introduced in [1]. We show that,…
We study cosmological perturbations in generalized Einstein scenarios and show the equivalence of inflationary observables both in the Jordan frame and the Einstein frame. In particular the consistency relation relating the tensor-to-scalar…
The formation of the cosmic microwave background radiation (CMBR) provides a very powerful probe of the early universe at the epoch of recombination. Specifically, it is possible to constrain the variation of fundamental physical constants…
We analyze a model of quintessence governed by an exponential potential and non-minimally coupled to gravity, in light of recent datasets, including cosmic microwave background, baryon acoustic oscillations, and supernovae distance moduli…
Coupled cosmologies can predict values for the cosmological parameters at low redshifts which may differ substantially from the parameters values within non-interacting cosmologies. Therefore, low redshift probes, as the growth of structure…
We use updated Hubble parameter and baryon acoustic oscillation data, as well as other lower-redshift Type Ia supernova, Mg II reverberation-measured quasar, quasar angular size, H II starburst galaxy, and Amati-correlated gamma-ray burst…
We use cosmic microwave background (CMB) and large-scale structure data to constrain cosmological models where the primordial perturbations have both an adiabatic and a cold dark matter (CDM) isocurvature component. We allow for a possible…
We discuss the problem of constraining cosmological parameters with cosmic microwave background band--power estimates. Because these latter are variances, they do not have gaussian distribution functions and, hence, the standard…
We present cosmological constraints on deviations of Newton's constant at large scales, analyzing latest cosmic microwave background (CMB) anisotropies and primordial abundances of light elements synthesized by big bang nucleosynthesis…
Newton's constant has observational effects on both the CMB power spectra and the light curves of SNIa. We use Planck data, BAO data and the SNIa measurement to constrain the varying Newton's constant $G$ during the CMB epoch and the…
Experimental searches for new, "fifth" forces are attracting a lot of attention because they allow to test theoretical extensions to the standard model. Here, we report a new experimental search for possible fifth forces, specifically…