相关论文: Does Positronium Form in the Universe ?

This paper follows "The physics and identity of Dark Energy", which is the acceleration energy of old photons. The present paper considers everything else in the decay of our universe; it is an ensemble called "old protons, etc."; the…

The first stars to form in the Universe may be powered by the annihilation of weakly interacting dark matter particles. These so-called dark stars, if observed, may give us a clue about the nature of dark matter. Here we examine which…

The formation of baryon asymmetry in the Universe is considered in the left-right asymmetry model of weak interaction. In this model, the nature of CP violation is associated with the presence of a right vector boson admixture, with a…

We propose a novel theoretical framework in which proton decay is induced by the dark matter. While proton decay requires violation of the $B+L$ symmetry, dark matter stability often relies on the presence of an unbroken symmetry. These…

Para positronium composed by an electron-antielectron pair is an unstable system decaying into two high energetic gamma photons via self annihilation process, due to the conservation of the charge conjugation parity in electromagnetically…

The origin of the hot phase of the early universe remains so far an unsolved puzzle. A viable option is entropy production through the decays of heavy Majorana neutrinos whose lifetimes determine the initial temperature. We show that…

Recent studies suggest that the process of symmetry breaking after inflation typically occurs very fast, within a single oscillation of the symmetry-breaking field, due to the spinodal growth of its long-wave modes, otherwise known as…

Assuming Galactic positrons do not go far before annhilating, a difference between the observed 511 keV annihilation flux distribution and that of positron production, expected from beta-plus decay in Galactic iron nucleosynthesis, was…

We determine the rates and energy and angular distributions of the positronium decays into a photon and a neutrino-antineutrino pair, Ps-->gamma+nu+anti-nu. We find that both positronium spin states have access to this decay channel,…

We approach to the ortho-positronium (o-Ps) as a relativistic two-body problem in $2+1$ dimensions in which o-Ps is composed of two-oppositely charged particles interacting via an attractive Coulomb force. In addition to separation of…

We review current cosmological constraints on the axion. We describe the basic mechanisms by which axions are created in the early universe, focussing on the standard thermal scenario where the dominant process is through axion radiation by…

The recent results of IceCube Neutrino Observatory include an excess of PeV neutrino events which appear to follow a broken power law different from the other lower energy neutrinos detected by IceCube. The possible astrophysical source of…

Axion-like dark matter whose symmetry breaking occurs after the end of inflation predicts enhanced primordial density fluctuations at small scales. This leads to dense axion minihalos (or miniclusters) forming early in the history of the…

Dark matter annihilation or decay could have a significant impact on the ionisation and thermal history of the universe. In this paper, we study the potential contribution of dark matter annihilation (s-wave- or p-wave-dominated) or decay…

We explored a distinct mechanism for matter creation via electron-positron pair production during bound-bound transitions in the deexcitation of one-muon ions. For ions with nuclear charges $Z\geq24$, transitions from low-lying excited…

We show that if photon possesses a tiny but non-vanishing mass the universe cannot be electrically neutral. Cosmological electric asymmetry could be generated either at an early stage by different evaporation rates of primordial black holes…

If the preon structure of quarks, leptons and gauge bosons will be proved then in the Universe during a relativistic phase transition the production of nonperturbative preon condensates has occured. Familons are collective excitations of…

Since it became evident that the CDM model for cosmic structure formation predicts smaller power on large scales than observed, many alternatives have been suggested. Among them, the existence of late decaying particle can cure it by…

In most models of dark energy the structure formation stops when the accelerated expansion begins. In contrast, we show that the coupling of dark energy to dark matter may induce the growth of perturbations even in the accelerated regime.…

The main stages in the evolution of a neutron star, from its birth as a proto-neutron star, to its old age as a cold, catalyzed configuration, are described. A proto-neutron star is formed in the aftermath of a successful supernova…