Related papers: The Dark Universe: The First Molecules
After inflation the Universe presumably undergoes a phase of reheating which in effect starts the thermal big bang cosmology. However, so far we have very little direct experimental or observational evidence of this important phase of the…
In the standard model of cosmology, the present evolution of the Universe is determined by the presence of two components of unknown nature. One of them is referenced as ``dark matter'' to justify the fact that it behaves cosmologically…
In cosmological models favored by current observations, the first astrophysical objects formed in dark matter halos at redshifts starting at z>20, and their properties were determined by primordial H_2 molecular chemistry. These…
The nature of dark matter remains one of the greatest unsolved mysteries in elementary particle physics. It might well be that the dark matter particle belongs to a dark sector completely secluded or extremely weakly coupled to the visible…
Phase transitions in the early universe are prime settings for the production of primordial black holes, since they can break the relatively quiescent homogeneity and isotropy of Friedmann-Robertson-Walker (FRW) cosmologies. These epochs of…
It is commonly assumed that the energy density of the Universe was dominated by radiation between reheating after inflation and the onset of matter domination 54,000 years later. While the abundance of light elements indicates that the…
Dark matter (DM) comes from long-range gravitational observations, and it is considered as something that does not interact with ordinary matter or emits light. However, also on much smaller scales, a number of unexpected observations of…
Primordial black holes with a narrow mass range are regarded as a nonrelativistic fluid component with an equation of state for dust. The impact of the black hole evaporation on the dynamics of the early universe is studied by resorting to…
If the next fundamental level of matter occurs (preons) then dark matter must consist of familons containing a "hot" component from massless particles and a "cold" component from massive particles. During evolution of the Universe this dark…
The evolution of the Universe is the ultimate laboratory to study fundamental physics across energy scales that span about 25 orders of magnitude: from the grand unification scale through particle and nuclear physics scales down to the…
The hypothesis that dark matter is converted into visible particles in active galactic nuclei is investigated. If dark matter consists of stable superheavy neutral particles and active galactic nuclei are rotating black holes, then, due to…
This paper may solve the dark-energy problem because our universe is not alone, and the multiverse is a powerful part of the cosmos. The decay of our aging universe is reviewed first. The accelerated expansion takes the decay debris into…
During the past two decades, cosmologists turned to particle physics in order to explore the physics of the very early Universe. The main link between the physics of the smallest and largest structures in the Universe is the idea of…
The evolution of the perturbations in the energy density and the particle number density in a flat Friedmann-Lemaitre-Robertson-Walker universe in the radiation-dominated era and in the epoch after decoupling of matter and radiation is…
We study the effects of dark-matter annihilation during the epoch of big-bang nucleosynthesis on the primordial abundances of light elements. We improve the calculation of the light-element abundances by taking into account the effects of…
The cosmic expansion history proceeds in broad terms from a radiation dominated epoch to matter domination to an accelerated, dark energy dominated epoch. We investigate whether intermittent periods of acceleration are possible in the early…
Dark matter, one of the fundamental components of the universe, has remained mysterious in modern cosmology and particle physics, and hence, this field is of utmost importance at present moment. One of the foundational questions in this…
A mechanism of creation of stellar-like objects in the very early universe, from the QCD phase transition till BBN and somewhat later, is studied. It is argued that in the considered process primordial black holes with masses above a few…
Over the past few decades, a consensus picture has emerged in which roughly a quarter of the universe consists of dark matter. I begin with a review of the observational evidence for the existence of dark matter: rotation curves of…
The first stars to form in the Universe may be powered by the annihilation of weakly interacting dark matter particles. These so-called dark stars, if observed, may give us a clue about the nature of dark matter. Here we examine which…