Related papers: Entropy production by Q-ball decay for diluting lo…
The role of entropy production in the context of probing QCD properties at high densities and finite temperatures in ultra-relativistic collisions of heavy nuclei is inspected. It is argued that the entropy generated in these reactions…
Entropy production is a necessary ingredient for addressing the over-population of thermal relics. It is widely employed in particle physics models for explaining the origin of dark matter. A long-lived particle that decays to the known…
The gauge-mediated model of supersymmetry breaking implies that stable non-topological solitons, Q-balls, could form in the early universe and comprise the dark matter. It is shown that the inclusion of the effects from gravity-mediation…
Q-balls are non-topological solitons whose classical stability is ensured by a global $U(1)$ charge. In particular, Q-balls are produced in the framework of the Affleck-Dine baryogenesis where $U(1)$ charge is the baryon number. Since some…
We investigate the nucleosynthesis process in high-entropy ($s/k_{\rm B}\gtrsim100$) and very fast-expanding ($\tau_{\rm exp}\sim10^{-3}\ {\rm s}$) materials. In such a material with the electron fraction near 0.5, an interesting…
We investigate the Q-ball decay in the gauge-mediated SUSY breaking. Q balls decay mainly into nucleons, and partially into gravitinos, while they are kinematically forbidden to decay into sparticles which would be cosmologically harmful.…
In this work, we study the applications of entropy bounds in two toy cosmological models with particle production (annihilation), i.e., a radiation-dominated universe and a dust-dominated universe. We consider the co-moving volume and the…
The 511 keV photons from the galactic center can be explained by positrons produced through Q-ball decay. In the scheme of gauge-mediated supersymmetry breaking, large Q balls with lepton charge are necessarily long-lived. In particular,…
A very simplified model of the Universe is considered in order to propose an alternative approach to the irreversible evolution of the Universe at very early times. The entropy generation at the quantum stage can be thought as a consequence…
We study the formation of Q-balls in the early universe, concentrating on potentials with a cubic or quartic attractive interaction. Large Q-balls can form via solitosynthesis, a process of gradual charge accretion, provided some primordial…
We investigate cosmological effects concerning the late-time entropy production due to the decay of non-relativistic massive particles. The thermalization process of neutrinos after the entropy production is properly solved by using the…
We analyse a non-equilibrium exclusion process in which particles are created and annihilated in pairs and hop to the the right or to the left with different transition rates, $p$ and $q$, respectively. We have studied the dynamics of a…
We investigate how entanglement entropy can drive particle creation, deriving explicit relations between entropy and the radiated particle spectrum, the total number of particles, and the total energy. Particle production is computed for…
We consider a wide class of linear stochastic problems driven off the equilibrium by a multiplicative asymmetric force. The force brakes detailed balance, maintained otherwise, thus producing entropy. The large deviation function of the…
The entropy production occurring in relativistic hydrodynamical systems such as the quark-gluon plasma (QGP) formed in high-energy nuclear collisions is explored. We study mechanisms which change the composition of the fluid, i.e. particle…
We perform calculations of dark photon production and decay in the early universe for ranges of dark photon masses and vacuum coupling with standard model photons. Simultaneously and self-consistently with dark photon production and decay,…
The entropy growth in a cosmological process of pair production is completely determined by the associated squeezing parameter, and is insensitive to the number of particles in the initial state. The total produced entropy may represent a…
We consider the generation of entropy when particle pairs are created at a cosmological level. Making a reduction via the particle number basis, we compute the classical limit for the entropy generation due to the evolution of the matter…
Non topological solitons, Q-balls can arise in many particle theories with U(1) global symmetries. As was shown by Cohen et al. \cite{Qballscohen}, if the corresponding scalar field couples to massless fermions, large Q-balls are unstable…
Excited Q-balls are studied by numerical simulations in the Minimal Supersymmetric Standard Model with supersymmetry broken by a gravity mediated mechanism. It is found that there is a suppression factor of $\cO(10^{-2})$ in the rate at…