Related papers: QCD relics from the early Universe
Formation of stable domains filled with strongly correlated coherent quark matter is discussed in general terms and is exemplified further in the framework of the Generalised Nambu-Jona-Lasinio model. It is argued that such domains, if…
The abundance and size distribution of quark nuggets (QN), formed a few microseconds after the big bang due to first order QCD phase transition in the early universe, has been estimated. It appears that stable QNs could be a viable…
QCD-like theories in which the dark matter (DM) of the Universe is hypothesized to be a thermal relic in the form of a dark pion has been extensively investigated, with most studies neglecting the CP-violating $\theta$-angle associated with…
We calculate the size distribution of quark nuggets, which could be formed due to first order QCD phase transition in the early universe. We find that there are a large number of stable Quark Nuggets which could be a viable candidate for…
High energy collisions of particles may have created tiny black holes in the early Universe, which might leave stable remnants instead of fully evaporating as a result of Hawking radiation. If the reheating temperature was sufficiently…
The Universe may contain sufficiently small size matter-antimatter domains at temperatures of a few hundred MeV, without violating the success of Big Bang Nucleosynthesis. We demonstrate that this possibility enhances the keV scale sterile…
The scenario that some first-order phase transitions may have taken place in the early Universe offers us one of the most intriguing and fascinating questions in cosmology. Indeed, the role played by the latent "heat" or energy released in…
We discuss production of QCD axion dark matter in a novel scenario, which assumes time-varying scale of Peccei-Quinn symmetry breaking. The latter decreases as the Universe's temperature at early times and eventually stabilises at a large…
The very first stars to form in the Universe heralded an end to the cosmic dark ages and introduced new physical processes that shaped early cosmic evolution. Until now, it was thought that these stars lived short, solitary lives, with only…
The domain wall problem of the Peccei-Quinn mechanism can be solved if the Peccei-Quinn symmetry is explicitly broken by a small amount. Domain walls decay into axions, which may account for dark matter of the universe. This scheme is…
The universe would have been completely dark between the epoch of recombination and the development of the first non-linear structure. But at redshifts beyond 5 -- perhaps even beyond 20 -- stars formed within `subgalaxies' and created the…
Three current models of QCD in (1+1) dimensions are examined and extended in light-front coordinates. A pion of high momentum is found to have an infinite extent along its direction of motion.
QCD was shown to have a nontrivial vacuum structure due to the topology of the theta = theta+2*pi*n parameter. As a result of this nontrivial topology, in the large N_c limit, quasi-stable QCD domain walls appear, characterized by a…
The Peccei-Quinn solution to the strong CP problem provides a motivated framework rich in cosmological consequence. Thermal axion production is unavoidable if there is a thermal bath at early times. Scattering and decay processes of bath…
We present for the first time solutions in the gauged $U(1)\times U(1)$ model of Witten describing vortons -- spinning flux loops stabilized against contraction by the centrifugal force. Vortons were heuristically described many years ago,…
Modelling of Extreme Scattering Events suggests that the Galaxy's dark matter is an undetected population of cold, AU-sized, planetary-mass gas clouds. None of the direct observational constraints on this picture -- thermal/non-thermal…
Sterile neutrinos with masses in the keV range can be the dark matter, and their emission from a supernova can explain the observed velocities of pulsars. The sterile neutrino decays could produce the x-ray radiation in the early universe,…
It was recently shown that there exists metastable U(1)_A domain wall configurations in high-density QCD (\mu >> 1 GeV). In the following we will assess the stability of such non-trivial field configurations at intermediate densities (\mu <…
Strongly-coupled theories at the TeV can naturally drive a long period of supercooling in the early universe. Trapped into the deconfined phase, the universe could inflate and cool down till the temperature reaches the QCD strong scale. We…
Strong nuggets with a baryon number of $A\sim 10^{10-30}$ could be able to survive from the cosmic separation of the QCD phases, provided the transition from strange quark matter to strangeon matter is accounted for, thereby evading…