Related papers: Light Dark Matter: A Common Solution to the Lithiu…
The recent analysis from the SH0ES Collaboration has confirmed the existence of a Hubble tension between measurements at high redshift ($z> 1000$) and at low redshift ($z<1$) at the $5\sigma$ level with the low redshift measurement giving a…
Observations of low-metallicity halo stars have revealed a puzzling result: the abundance of \li7 in these stars is at least three times lower than their predicted primordial abundance. It is unclear whether the cause of this disagreement…
We investigate the production of dark radiation (DR) from axions and axion-like particles (ALPs) as potential origins of dark matter. Focusing on the dark matter misalignment mechanism, we examine non-thermal, pre-inflationary scenarios…
A current problem within the {\Lambda}CDM framework is the tension between late and early time measurements of the Hubble parameter today, H0. We entertain the possibility that dark energy modeled as multiple interacting axion-like-particle…
Early dark energy, an additional component of dark energy active in the decade of redshift before recombination, has emerged as one of the most effective models at reducing the $H_0$ tension between direct measurement of the Hubble…
We study a dark matter production mechanism based on decays of a messenger WIMP-like state into a pair of dark matter particles that are self-interacting via exchange of a light mediator. Its distinctive thermal history allows the mediator…
The simplest cosmological model ($\Lambda$CDM) is well-known to suffer from the Hubble tension, namely an almost $5 \sigma$ discrepancy between the (model-based) early-time determination of the Hubble constant $H_0$ and its late-time (and…
A cosmological model with a time-varying mass of electrons seems a promising solution for the so-called Hubble tension. We examine the big bang nucleosynthesis (BBN) constraints on the time-varying electron mass model, because a larger…
Dark energy and dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationally repulsive negative masses, which drive…
The answer is Yes! We indeed find that interacting dark energy can alleviate the current tension on the value of the Hubble constant $H_0$ between the Cosmic Microwave Background anisotropies constraints obtained from the Planck satellite…
Addressing the discrepancy between the late and early time measurements of the Hubble parameter, $H_0$, and the so-called $S_8$ parameter has been a challenge in precision cosmology. Several models are present to address these tensions, but…
Observations of the cosmic microwave background (CMB) together with weak lensing measurements of the clustering of large scale cosmological structures and local measurements of the Hubble constant pose a challenge to the standard…
We briefly describe the cosmological lithium problems followed by a summary of our recent theoretical work on the magnitude of the effects of electron screening, the possible existence of dark matter parallel universes and the use of…
Despite the remarkable success of the $\Lambda$Cold Dark Matter ($\Lambda$CDM) cosmological model, a growing discrepancy has emerged (currently measured at the level of $\sim 4-6 \sigma$) between the value of the Hubble constant $H_0$…
In this manuscript we reassess the potential of interacting dark matter-dark energy models in solving the Hubble constant tension. These models have been proposed but also questioned as possible solutions to the $H_0$ problem. Here we…
We examine interactions between dark matter and dark energy in light of the latest cosmological observations, focusing on a specific model with coupling proportional to the dark energy density. Our data includes Cosmic Microwave Background…
One of the problem revealed recently in cosmology is a so-called Hubble tension (HT), which is the difference between values of the present Hubble constant, measured by observation of the universe at redshift $z \lesssim 1$, and by…
We address some recent erroneous claim that $H_0$ observations are difficult to accommodate with LTB cosmological models, showing how to construct solutions in agreement with an arbitrary value of $H_0$ by re-writing the exact solution in…
We study the gravitational production of super-Hubble-mass dark matter in the very early universe. We first review the simplest scenario where dark matter is produced mainly during slow roll inflation. Then we move on to consider the cases…
The majoron, a neutrinophilic pseudo-Goldstone boson conventionally arising in the context of neutrino mass models, can damp neutrino free-streaming and inject additional energy density into neutrinos prior to recombination. The combination…