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In this methodological note we discuss several topics related to interpretation of some basic cosmological principles. We demonstrate that one of the key points is the usage of synchronous reference frames. The Friedmann-Robertson-Walker one is the m ost known example of them. We describe how different quantities behave in this frame. Special attention is paid to potentially observable parameters. We discuss different variants for choosing measures of velocity and acceleration representing the Hubble flow, and present illustrative calculations of apparent acceleration in flat $Lambda CDM$ model for various epochs. We generalize description of the tethered galaxies problem for different velocity measures and equations of state, and illustrate time behavior of velocities and redshifts in the $Lambda CDM$ model.
We have considered polar ring galaxy candidates, the images of which can be found in the SDSS. The sample of 78 galaxies includes the most reliable candidates from the SPRC and PRC catalogs, some of which already have kinematic confirmations. We anal yze the distributions of studied objects by the angle between the polar ring and the central disk, and by the optical diameter of the outer ring structures. In the vast majority of cases, the outer structures lie in the plane close to polar (within 10-20 deg) which indicates the stability of the corresponding orbits in the gravitational potential of the halo. Moderately inclined outer structures are observed only in about 6% of objects which probably indicates their short lifetime. In such an unstable configuration, the polar ring would often cross the disk of the galaxy, being smaller than it in the diameter. We show that the inner polar structures and outer large-scale polar rings form a single family in the distribution of diameters normalized to the optical size of the galaxy. At the same time, this distribution is bimodal, as the number of objects with d_ring= (0.4-0.7)*d_disk is negligible. Such a shape of size distribution is most likely due to the fact that the stability of polar orbits in the inner regions of galaxies is maintained by the bulge or the bar, while in the outer regions it is provided by the spheroidal (or triaxial) halo.
The confinement mechanism proposed earlier by the author is employed for to compute the decay constants $f_P$ corresponding to leptonic decays $Pto l^pm+ u_l$, $l=mu, e$, where $P$ stands for any meson from $pi^pm$, $K^pm$. For this aim the weak axia l form factor of $P$-meson is nonperturbatively calculated. The study entails estimates for parameters of the confining SU(3)-gluonic field in charged pions and kaons. The corresponding estimates of the gluon concentrations, electric and magnetic colour field strengths are also adduced for the mentioned field at the scales of the mesons under consideration. Further the obtained results are applied to the problem of chiral symmetry breaking in quantum chromodynamics (QCD). It is shown that in chirally symmetric world masses of pions and kaons are fully determined by the confining SU(3)-gluonic field among (massless) $u$, $d$ and $s$ quarks and not equal to zero. Accordingly chiral symmetry is sufficiently rough approximate one holding true only when neglecting the mentioned SU(3)-gluonic field between quarks and no additional mechanism of the spontaneous chiral symmetry breaking connected to the so-called Goldstone bosons is required. Finally, a possible relation of the results obtained with a phenomenological string-like picture of confinement is discussed too.
We have studied the kinematics of the ionized gas and stellar component in Mrk334 using methods of panoramic (3D) spectroscopy. The observations were performed at the prime focus of the SAO RAS 6-m telescope with the integral-field spectrograph MPFS (Afanasiev et al. 2001) and with a scanning Fabry-Perot interferometer (FPI), installed on the multimode device SCORPIO (Afanasiev & Moiseev 2005). Based on these data, the monochromatic maps and velocity fields in different emission lines of the ionized gas were constructed. The diagnostic diagrams have been made based on the emission lines ratios.
139 - M. V. Zhabitsky 2007
We performed the first direct calculation of the probability of pionium (pi+pi- atom) ionization in the target. The dependence of the probability of pionium ionization in the target as a function of the pionium lifetime is established. These calculat ions are of interest of the DIRAC experiment at CERN, which aims to measure the pionium lifetime with high precision.
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