Related papers: Ballistic Dark Matter oscillates above $\Lambda$CD…
A smooth unclustered dark matter component with negative presure could reconcile a flat universe with the many observations that find a density in ordinary, clustered matter well below the critical density and also explain the recent high…
In the paper, we consider two models in which dark energy is coupled with either dust matter or dark matter, and discuss the conditions that allow more time for structure formation to take place at high redshifts. These models are expected…
We revisit cosmological neutrino mass bounds when a fraction of dark matter is allowed to decay to massless dark radiation. By compensating the late-time increase in the matter density induced by neutrinos becoming non-relativistic,…
We investigate the characteristic modifications in the evolving cosmological perturbations when dark energy interacts with dust-like matter, causing the latter's background energy density fall off with time faster than usual. Focusing in…
Modified Dark Matter (MDM) is a phenomenological model of dark matter, inspired by gravitational thermodynamics, that naturally accounts for the universal acceleration constant observed in galactic rotation curve data; a critical…
Over the last decade, warm dark matter (WDM) has been repeatedly proposed as an alternative scenario to the standard cold dark matter (CDM) one, potentially resolving several disagreements between the CDM model and observations on small…
We study a phenomenological dark matter model described as a collisionless relativistic kinetic gas in a spatially flat Friedmann-Lema\^itre-Robertson-Walker universe. After normalization to the observed present-day dark matter abundance,…
Recently a new particle physics model called Bound Dark Matter (BDM) has been proposed in which dark matter (DM) particles are massless above a threshold energy (Ec) and acquire mass below it due to nonperturbative methods. Therefore, the…
The cosmological QCD transition affects primordial density perturbations. If the QCD transition is first order, the sound speed vanishes during the transition and density perturbations fall freely. For scales below the Hubble radius at the…
We consider decaying dark matter (DDM) as a resolution to the possible tension between cosmic microwave background (CMB) and weak lensing (WL) based determinations of the amplitude of matter fluctuations, $\sigma_8$. We perform N-body…
In this work, we carry out a comprehensive perturbative analysis of four cosmological models featuring a sign-switching cosmological constant. Among these, we include the well-known $\Lambda_{\rm s}$CDM model, characterised by an abrupt…
The formation of large scale structure is independent of the nature of the cold dark matter (CDM), however the fate of very small scale inhomogeneities depends on the micro-physics of the CDM particles. We investigate the matter power…
Atomic dark matter is a simple but highly theoretically motivated possibility for an interacting dark sector that could constitute some or all of dark matter. We perform a comprehensive study of precision cosmological observables on minimal…
We study the evolution of cosmological perturbations in dark-matter models with elastic and velocity-independent self interactions. Such interactions are imprinted in the matter-power spectrum as dark acoustic oscillations, which can be…
Early-matter-like dark energy is defined as a dark energy component whose equation of state approaches that of cold dark matter (CDM) at early times. Such a component is an ingredient of unified dark matter (UDM) models, which unify the…
We consider a possibility to explain the observed suppression of the second acoustic peak in the anisotropy spectrum of the Cosmic Microwave Background (CMB) by interaction between a fraction of non-baryonic Cold Dark Matter (CDM) and…
There is a vast literature on Dark Matter (DM) with many reviews of specific topics only a small fraction of which will be mentioned. I start with a very brief review of cosmology which underlies much of DM research and some relevant…
We consider the history of the universe from a possible big bang or a bounce into a late period of a unified interacting dark energy - dark matter model. The model is based on the Two Measures Theories (T.M.T.) which introduces a metric…
The Hubble tension and the recently reported anomaly in data from the Dark Energy Spectroscopic Instrument (DESI) are considered to pose serious challenges to the standard $\Lambda$CDM model of cosmology. In this work, we show that…
After numerous astronomical and experimental searches, the precise particle nature of dark matter is still unknown. The standard Weakly Interacting Massive Particle(WIMP) dark matter, despite successfully explaining the large-scale features…