Related papers: Barrow Cosmology and Big-Bang Nucleosynthesis
Barrow, and Barrow and collaborators, have put forward theoretical models with variable fundamental constants including JBD theories. The experimental evidence for an accelerating Universe points out to a deceleration parameter…
In this paper, starting from the modified Einstein field equations, we derive the modified scalar spectral index $n_{s}$ and the modified tensor-to-scalar ratio $r$ in Barrow entropy model, calculate their values for the power-law,…
We present a comprehensive investigation exploring the theoretical framework of Einstein-Aether gravity theory when combined with two modified cosmological paradigms: the Barrow Agegraphic Dark Energy (BADE) and its newer variant, the New…
The Hubble parameter inferred from cosmic microwave background observations is consistently lower than that from local measurements, which could hint towards new physics. Solutions to the Hubble tension typically require a sizable amount of…
We present a modified cosmological scenario that arises from the application of non-extensive thermodynamics with varying exponent. We extract the modified Friedmann equations, which contain new terms quantified by the non-extensive…
We investigate Big Bang nucleosynthesis (hereafter, BBN) in a cosmic environment characterized by a distribution of small-scale matter/antimatter domains. Production of antimatter domains in a baryo-asymmetric universe is predicted in some…
Big Bang Nucleosynthesis (BBN), as one of the earliest processes in the universe accessible to direct observation, offers a powerful and independent probe of the cosmic expansion history. With recent advances in both theory and observation,…
As we know that the horizon area of a black hole will increase when it absorbs matters. While based on Barrow's idea of fractal black hole horizon, ones [Phys. Lett. B 831 (137181) 2022] had proposed that for a spherically fractal structure…
Applying Clausius relation, $\delta Q=TdS$, to apparent horizon of a FRW universe with any spatial curvature, and assuming that the apparent horizon has temperature $T=1/(2\pi \tilde {r}_A)$, and a quantum corrected entropy-area relation,…
One of the three testaments in favor of the big bang theory is the prediction of the primordial elemental abundances in the big-bang nucleosynthesis (BBN). The Standard BBN is a parameter-free theory due to the precise knowledge of the…
The quantum scenario concerning Hawking radiation, gives us a precious clue that a black hole has its temperature directly connected to its area gravity and that its entropy is proportional to the horizon area. These results have shown that…
We discuss the present bounds on the relativistic energy density in the Universe parameterized in terms of the effective number of neutrinos N using the most recent cosmological data on Cosmic Microwave Background (CMB) temperature…
According to the standard models of particle physics and cosmology, there should be a background of cosmic neutrinos in the present Universe, similar to the cosmic microwave photon background. The weakness of the weak interactions renders…
Neutrino physics in the early Universe is key to our understanding of later cosmological stages, such as primordial nucleosynthesis (BBN) or the formation of large-scale structures. The coming decade promises new experimental results to…
Primordial nucleosynthesis is a success story of the standard big bang (SBB) cosmology. We explore nucleosynthesis in possible models very different from SBB in which the cosmological scale factor increases linearly with time right through…
We use Big Bang Nucleosynthesis calculations and light element abundance data to constrain the relative variation of the deuteron binding energy since the universe was a few minutes old, $\delta Q = Q(BBN)-Q(present)$. Two approaches are…
We consider Big Bang nucleosynthesis and the cosmic microwave background when both the neutrino temperature and neutrino number are allowed to vary from their standard values. The neutrino temperature is assumed to differ from its standard…
We have analyzed the Barrow holographic dark energy (BHDE) in the framework of the flat FLRW Universe by considering the various estimations of Barrow exponent $\triangle$. Here we define BHDE, by applying the usual holographic principle at…
For a brief time in its early evolution the Universe was a cosmic nuclear reactor. The expansion and cooling of the Universe limited this epoch to the first few minutes, allowing time for the synthesis in astrophysically interesting…
We update Standard Big Bang Nucleosynthesis (SBBN) calculations on the basis of recent nuclear physics compilations (NACRE in particular), experimental and theoretical works. By a Monte--Carlo technique, we calculate the uncertainties on…