Related papers: Nucleosynthesis in a simmering univeerse
Big-bang nucleosynthesis (BBN), today a pillar of modern cosmology, began with the trailblazing 1948 paper of Alpher, Bethe and Gamow. In it, they proposed non-equilibrium nuclear processes in the early Universe ($t \sim 1000\,$sec) and an…
We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component…
Contrary to a recent claim, the inferred primordial abundances of the light elements are quite consistent with the expectations from standard big bang nucleosynthesis when attention is restricted to direct observations rather than results…
Big Bang Nucleosynthesis (BBN) relates key cosmological parameters to the primordial abundance of light elements. In this paper, we point out that the recent observations of Cosmic Microwave Background anisotropies by the Planck satellite…
A brief review of standard big bang nucleosynthesis theory and the related observations of the light element isotopes is presented. Implications of BBN on chemical evolution and constraints on particle properties will also be discussed.
We perform calculations of dark photon production and decay in the early universe for ranges of dark photon masses and vacuum coupling with standard model photons. Simultaneously and self-consistently with dark photon production and decay,…
Neutrino non-standard interactions (NSI) with electrons, predicted in many extended theoretical models of particle physics, are known to alter the picture of neutrino decoupling from the cosmic plasma. We update previous analyses of…
In the past years 'quintessence' models have been considered which can produce the accelerated expansion in the universe suggested by recent astronomical observations. One of the key differences between quintessence and a cosmological…
We investigate observable cosmological aspects of sterile neutrino dark matter produced via the freeze-in mechanism. The study is performed in a framework that admits many cosmologically interesting variations: high temperature production…
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 what we know on nucleosynthesis in the Universe and hypotheses that have been made in this regard. A brief description of the Universe's evolution during its different stages is offered, indicating which are the periods and…
The hot big-bang cosmology provides a reliable accounting of the Universe from about $10^{-2}\sec$ after the bang until the present, as well as a robust framework for speculating back to times as early as $10^{-43}\sec$. Cosmology faces a…
Primordial or big bang nucleosynthesis (BBN) is one of the three historical strong evidences for the big bang model. Standard BBN is now a parameter free theory, since the baryonic density of the Universe has been deduced with an…
Experiments with cold and ultracold neutrons have reached a level of precision such that problems far beyond the scale of the present Standard Model of particle physics become accessible to experimental investigation. Due to the close links…
In this paper we investigate the primordial nucleosynthesis in $\mathscr{L}=\varepsilon^{2-2\beta}R^\beta+{16\pi}m_P^{-2}\mathscr{L}_m$ gravity, where $\varepsilon$ is a constant balancing the dimension of the field equation, and…
To constrain the universe before recombination (380000 years after the Big Bang), we mostly rely on the measurements of the primordial abundances that indicate the first insight into the thermal history of the universe. The first production…
We address the emerging discrepancy between the Big Bang Nucleosynthesis data and standard cosmology, which asks for a bit longer evolution time. If this effect is real, one possible implication (in a framework of brane cosmology model) is…
$\beta$-decay, a process that changes a neutron into a proton (and vice versa), is the dominant decay mode of atomic nuclei. This decay offers a unique window to physics beyond the standard model, and is at the heart of microphysical…
We put bounds on the variation of the value of the fine structure constant $\alpha$, at the time of Big Bang nucleosynthesis. We study carefully all light elements up to $^7$Li. We correct a previous upper limit on $|\Delta \alpha /…
In this work, we investigate Big Bang Nucleosynthesis (BBN) within the framework of $f(T,{L}_m)$ gravity, where the gravitational Lagrangian is generalized as a function of the torsion scalar $T$ and the matter Lagrangian ${L}_m$. We…