Related papers: The Supercooled Universe
If axions exist they are efficiently produced in the hot and dense interior of stars, providing a novel energy-loss mechanism. In order to avoid a conflict with the observed properties of stars, one can derive a lower limit on the…
Dark matter drops out of kinetic equilibrium with standard model particles when the momentum-transfer rate equals the expansion rate. In a radiation-dominated universe, this occurs at essentially the same time as dark matter kinetically…
The 21-cm signal from the cosmic reionization epoch can shed light on the history of heating of the primordial intergalactic medium (IGM) at z~30-10. It has been suggested that X-rays from the first accreting black holes could significantly…
At high nuclear density and small temperature, due to the asymptotic freedom property of Quantum ChromoDynamics and to the existence of an attractive channel in the color interaction, diquark condensates might be formed. Since these…
Axions are produced during a period of dilaton-driven inflation by amplification of quantum fluctuations. We show that for some range of string cosmology parameters and some range of axion masses, primordial axions may constitute a large…
Clusters of galaxies are thought to contain about ten times as much dark matter as baryonic matter. The dark component therefore dominates the gravitational potential of the cluster, and the baryons confined by this potential radiate X-rays…
Preheating following the inflationary phase in models of open inflation is considered. The most significant difference from a preheating scenario in flat space is that supercurvature modes can be populated and amplified in the open…
Current observations of the cosmic microwave background could confirm an increase in the radiation energy density after primordial nucleosynthesis but before photon decoupling. We show that, if the gravitino problem is solved by a light…
The gravitino may well play an important role in cosmology, not only because its interactions are Planck-suppressed and therefore long-lived, but also because it is copiously produced via various processes such as particle scatterings in…
It is quite plausible that the mass of the dark matter particle increases significantly after its freeze-out, due to a scalar field rolling to large values. We describe a realization of this scenario in the context of thermal inflation…
The electroweak (EW) phase transition in the early Universe might be supercooled due to the presence of the classical scale invariance involving Beyond the Standard Model (BSM) sectors and the supercooling could persist down till a later…
As a planet ages it cools and its radius shrinks, at a rate set by the efficiency with which heat is transported from the interior out to space. The bottleneck for this transport is at the boundary between the convective interior and the…
We explain how a $SU(N_c)$ gauge theory, decoupled from the standard model and with a high-lying strong coupling scale, can incorporate apparently unrelated cosmological features, such as Inflation and dark matter, using well-understood…
Axions and axion-like particles can be generated in the early universe through mechanisms such as misalignment production, thermal processes, and the decay of topological defects. In this study, we show that scalar perturbations in the…
The axions produced during the QCD phase transition by vacuum realignment, string decay and domain wall decay thermalize as a result of their gravitational self-interactions when the photon temperature is approximately 500 eV. They then…
Under general circumstances full thermal equilibrium may not be established for a long period after perturbative or non-perturbative decay of the inflaton has completed. One can instead have a distribution of particles which is in kinetic…
We study the finite temperature and density effects on beta decay rates to compute their contributions to nucleosynthesis. QED type corrections to beta decay from the hot and dense background are estimated in terms of the statistical…
The search for supersymmetric partners at Large Hadron Collider revealed negative result. Though, strictly speaking, it does not exclude low energy supersymmetry, but still it leads to strong constraints of the parameter space. Therefore…
In supersymmetric theories, the Peccei-Quinn symmetry has a complex extension as a symmetry of the superpotential, so that the scalar potential always has an almost flat direction, the dilaton. We discuss how coherent oscillation of the…
Cosmological simulations of the low-density intergalactic medium exhibit a strikingly tight power-law relation between temperature and density that holds over two decades in density. It is found that this relation should roughly apply Delta…