Related papers: A Quantum Phase Transition in the Cosmic Ray Energ…
Observations of cosmic rays have been improved at all energies, both in terms of higher statistics and reduced systematics. As a result, the all particle cosmic ray energy spectrum starts to exhibit more structures than could be seen…
The thermodynamical properties of a generalized Dicke model are calculated and related with the critical properties of its energy spectrum, namely the quantum phase transitions (QPT) and excited state quantum phase transitions (ESQPT). The…
The knee of cosmic ray spectra reflects the maximum energy accelerated by galactic cosmic ray sources or the limit to the ability of galaxy to bind cosmic rays. The measuring of individual energy spectra is a crucial tool to ascertain the…
Cosmic rays are charged relativistic particles that reach the Earth with extremely high energies, providing striking evidence of the existence of effective accelerators in the Universe. Below an energy around $\sim 10^{17}$ eV cosmic rays…
Molecular quantum electrodynamics leads to photon frequency shifts and thus to changes in condensed matter free energies often called the Casimir effect. Strong quantum electrodynamic coupling between radiation and molecular motions can…
Recent precise measurements of cosmic ray (CR) spectra show that the energy distribution of protons is softer than those of heavier nuclei, and there are spectral hardenings for all nuclear compositions above $\sim$200 GV. Models proposed…
An update of the status of the knee in the cosmic ray energy spectrum at 3-4 PeV is presented. We argue that the evidence in favour of the presence of a 'single source' is even stronger than before.
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…
First-order phase transitions exist in many models beyond the Standard Model and can generate detectable stochastic gravitational waves for a strong one. Using the cosmological observables in big bang nucleosynthesis and cosmic microwave…
The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances…
We investigate the 1D plane-parallel front connecting the warm ($10^4$ K) and hot ($10^6$ K) phases of the circumgalactic medium (CGM), focusing on the influence of cosmic rays (CRs) in shaping these transition layers. We find that cosmic…
Physical processes related to cosmological first-order phase transitions are discussed and reviewed in this introductory part of dissertation. I first describe cosmological phase transitions on a general level, concentrating on bubble…
We study weakly first order cosmological phase transitions in finite temperature field theories. Focusing on the standard electroweak theory and its minimal supersymmetric extension, we identify the regimes of Higgs masses for which the…
The production of energetic particles in the universe remains one of the great mysteries of modern science. The mechanisms of acceleration in astrophysical sources and the details about the propagation through the galactic and extragalactic…
Phase transitions, as the condensation of a gas to a liquid, are often revealed by a discontinuous behavior of thermodynamic quantities. For liquid Helium, for example, a divergence of the specific heat signals the transition from the…
The specific heat, magnetization and thermal expansion of single crystals of antiferromagnetic insulator EuTe, measured at temperatures down to 2 K and in magnetic fields up to 90 kOe, demonstrate non trivial properties. The Neel…
We study a quantum thermal engine model for which the heat transfer law is determined by Einstein's theory of radiation. The working substance of the quantum engine is assumed to be a two-level quantum systems of which the constituent…
We study the physics of quantum phase transitions from the perspective of non-equilibrium thermodynamics. For first order quantum phase transitions, we find that the average work done per quench in crossing the critical point is…
The propagation of high-energy cosmic rays in the Galaxy is investigated. Solutions of a diffusion model are combined with numerically calculated trajectories of particles. The resulting escape path length and interaction path length are…
The ratio of the number of muons with a threshold of 1 GeV and charged particles at a distance of 600 m from the axis is analyzed. Air showers with energies above 5 EeV and zenith angles with less than 60 degrees are considered. Comparison…