In this study, we aimed to measure the directly ionizing component (muons and photons) and the indirectly ionizing component (neutrons) of the cosmic-ray spectra and evaluate their dose rate contribution to the total dose rate on a ground level in Japan. Measurements were carried out in Tohoku University, Japan, from October 2000. The pulse-height spectra of the cosmic-ray photons and muons wer...

Recent developments in string theory suggest that cosmic strings could be formed at the end of brane inflation. Supergravity provides a realistic model to study the properties of strings arising in brane inflation. Whilst the properties of cosmic strings in flat space-time have been extensively studied there are significant complications in the presence of gravity. We study the effects of gravi...

Radiative transfer equilibrium models of nearby interstellar matter (ISM) are required to determine the boundary conditions of the heliosphere from astronomical observations of nearby stars. These models are also constrained by data on the ISM inside of the solar system, including pickup ion, anomalous cosmic rays, and in situ He data. The two best ISM models give semi-empirical filtration fact...

The interaction between concepts of irreversibility and the development of non-equilibrium statistical mechanics is discussed with particular reference to certain 'paradoxes' that retarded this development A recently evolved attitude towards the general problem of irreversibility may be considered responsible for a number of practical advances in this field. My subject is the interaction betwee...

We propose a different view of the dilemma concerning the coldness of the local cosmic flow and its repercussions for the global Universe. We stress the fact that our cosmic neighbourhood embodies a region of rather particular circumstances, whose dynamics and kinematics are substantially influenced by its location in between the Great Attractor region and the Pisces-Perseus chain. On the basis...

Recently we have shown that the observed knee structure is reproduced well by a superposition of the hypothetical extragalactic cosmic rays modulated by the galactic wind and the galactic cosmic rays originating in supernova remnants. We reexamine this model assuming the chemical composition of the hypothetical extragalactic cosmic rays is the same as that of the galactic cosmic rays of superno...

We investigate the problem of transition from galactic cosmic rays to extragalactic ultra high energy cosmic rays. Using the model for extragalactic ultra high energy cosmic rays and observed all-particle cosmic ray spectrum, we calculate the galactic spectrum of iron nuclei in the energy range 108 − 109 GeV. The flux and spectrum predicted at lower energies agree well with the KASCADE data. Th...

The isotropic component of the γ-ray flux between 100MeV and 100EeV (10 eV) contains important information about the origin of highest energy cosmic rays and the extragalactic magnetic field (EGMF). Using numerical simulations of extragalactic cosmic and γ-ray propagation we show that an average fraction of ≃ 10% γ-rays in the total cosmic ray flux around 10EeV would imply both a non-accelerati...

In this paper the collision of two cosmic string loops is studied. After collision junctions are formed and the loops are entangled. We show that after their formation the junctions start to unzip and the loops disentangle. This analysis provides a theoretical understanding of the unzipping effect observed in numerical simulations of a network of cosmic strings with more than one type of cosmic...