Related papers: The Supercooled Universe
The three phase transitions - the GUT, the electro-weak and the quark-hadron, which the universe is assumed to have undergone produce very important physical effects if they are assumed to be of first order. It is also important that enough…
The QCD phase diagram might exhibit a first order phase transition for large baryochemical potentials. We explore the cosmological implications of such a QCD phase transition in the early universe. We propose that the large baryon-asymmetry…
We derive general constraints on supersymmetric extension of axion models, in particular paying careful attention to the cosmological effects of saxion. It is found that for every mass range of the saxion from keV to TeV, severe constraints…
The evolution of the Universe between inflation and the onset of big bang nucleosynthesis is difficult to probe and largely unconstrained. This ignorance profoundly limits our understanding of dark matter: we cannot calculate its thermal…
Quasi-conformal models are an appealing scenario that can offer naturally a strongly supercooled phase transition and a period of thermal inflation in the early Universe. A crucial aspect for the viability of these models is how the…
It has recently been shown that if the dark matter is in thermal equilibrium with a sector that is highly decoupled from the Standard Model, it can freeze-out with an acceptable relic abundance, even if the dark matter is as heavy as ~1-100…
Since the thermal history of the Universe is unknown before the epoch of primordial nucleosynthesis, the largest temperature of the radiation dominated phase (the reheating temperature) might have been as low as 1 MeV. We perform a…
Regarding long life particles produced during preheating after inflation as dark matter, we find that its back reaction on the field $\phi$ could lock $\phi$ in a false vacuum up to today. This false vacuum can drive the accelerated…
A kinetic mixing between the axion and the inflaton allows for a production of axion dark matter even if the inflationary Hubble scale is smaller than the zero-temperature axion mass. We analyze the axion dynamics in this recently…
It is usually assumed that dark matter is produced during the radiation dominated era. There is, however, no direct evidence for radiation domination prior to big-bang nucleosynthesis. Two non-standard thermal histories are considered. In…
We show that an adiabatic increase of the supercurrent along a superconductor with lines of nodes of the order parameter on the Fermi surface can result in a cooling effect. The maximum cooling occurs if the supercurrent increases up to its…
We report that the hypothesis that the upper bound on the axion decay constant can be moved up beyond $10^{12}$ GeV in models with a stronger QCD in the early universe is not realized. This proof is possible by studying the superpotential…
In all supersymmetric theories, gravitinos, with mass suppressed by the Planck scale, are an obvious candidate for dark matter; but if gravitinos ever reached thermal equilibrium, such dark matter is apparently either too abundant or too…
In the framework where the strong coupling is dynamical, the QCD sector may confine at a much higher temperature than it would in the Standard Model, and the temperature-dependent mass of the QCD axion evolves in a non-trivial way. We find…
The decoupling of a cold relic, during a decaying-particle-dominated cosmological evolution is analyzed, the relic density is calculated both numerically and semi-analytically and the results are compared with each other. Using plausible…
The standard theoretical estimation of the thermal dark matter abundance may be significantly altered if properties of dark matter particles in the early universe and at the present cosmological epoch differ. This may happen if, e.g., a…
We compute the thermal axino production rate in supersymmetric QCD to leading order in the gauge coupling. Using hard thermal loop resummation and the Braaten-Yuan prescription, we obtain a finite result in a gauge-invariant way, which…
We introduce a class of unified supersymmetric axion theories with unified and PQ symmetries broken by the same set of fields at a scale $\sim 2\times 10^{16}$ GeV. A typical domain wall number of order 30 leads to an axion decay constant…
We present an overview of the arguments which lead to the picture that at low temperatures the QCD matter not far above a critical confinement-deconfinement density exists in one of several distinct superfluid phases exhibiting the quantum…
Thermal freeze-out or freeze-in during a period of early matter domination can give rise to the correct dark matter abundance for $\langle \sigma_{\rm ann} v \rangle_{\rm f} < 3 \times 10^{-26}$ cm$^3$ s$^{-1}$. In the standard scenario, a…