In a homogeneous pionic gas system, chemical nonequilibrium process is considered to understand its effect in the expansion processes that are realized immediately after heavy ion collisions. The chemical relaxation time is calculated by incorporating the π+π ↔ π+π+π+π reaction, which is given in the second order of perturbation in the σ model. The π + π ↔ π + π + π + π reaction is assumed to b...

Cosmic Microwave Background (CMB) anisotropies have been recognized as one of the most important observational quantities to understand the early stage of our universe. In this paper, recent development of theoretical works on CMB anisotropies are summarized and it is shown that temperature uctuations of CMB contain rich information, i.e., cosmological parameters, geometry of the universe, init...

The pseudorapidity dependence of elliptic flow in Au+Au collisions at 130 A GeV is studied within a full three-dimensional hydrodynamic model in the light-cone coordinate. First, we prepare two initial conditions in the hydrodynamic model for analyzing elliptic flow. Both initial conditions lead to reasonable agreement with single particle spectra in central and semi-central collisions. Next, b...

the iranian civil code has limited the effects of unknown condition to nullification of such condition provided that it results in ignorance with respect to consideration. the code conveys no explicit provision concerning the effect of such condition not resulting in the ignorance. unknown condition refers to a condition on which there is not complete and comprehensive knowledge. this article l...