Modulations of X-ray spectra from extragalactic sources might provide a signature of photons converting into axion-like particles (ALPs) when traversing a region with a large-scale magnetic field. A crucial unknown […]

In 1976, S. Weinberg and his student, E. Gildener (GW), proposed multi-Higgs models of electroweak symmetry breaking which are clas- sically scale-invariant. If this scale invariance is spontaneously broken, the […]

 Cosmological first-order phase transition are said strongly supercooled when the nucleation temperature is much smaller than the critical temperature. They are typical of  potentials which feature nearly scale-invariance, for which […]

The goal of identifying the Standard Model of particle physics and its extensions within string theory has been one of the principal driving forces in string phenomenology. Recently, the incorporation […]

Star forming galaxies (SFGs) are powerful factories of high-energy cosmic rays. Their star formation rate (SFR) is a key physical property characterizing both the total energy budget and the transport conditions of such particle populations. Tight correlations are in fact observed between the SFR and the non-thermal radio and gamma-ray luminosity of several SFGs. I […]