We study a static spherically symmetric problem with a black hole and radially directed geodesic flows of dark matter. The obtained solutions have the following properties. At large distances, the gravitational field produces constant velocities of circular motion, i.e. flat rotation curves. At smaller distances, the field switches to Newtonian regime, then to Schwarzschild regime. Deviations from Schwarzschild regime start below the gravitational radius. The dark matter prevents the creation of event horizon, instead, a spherical region possessing extremely large redshift is created. The structure of space-time for the obtained solutions is investigated and the implications for the models of the galaxies are discussed
The vertex y + 3~ has been investigated in the reaction of pion pair production by pions in the nuclear Coulomb field, rii-+ ( Z , A 1-r-+no+ (2, A ) , in the region of low-invariant-mass r -T O pairs. The experiment has been carried out in the 40-GeV pion beam of the I H E P accelerator (Serpukhov) with the SIGMA spectrometer. We have measured for the first time the cross section of the reaction in the region of momentum transfer squared q 2 < 2 X 1 0 -' (~e V / c )~, U / Z ' = 1.63k0.2310.13 nb, and the y -3 r coupling constant F'"= 12.9k0.9iO. 5 G~V P ' , where the first (second) error is statistical (systematic). The obtained result agrees with the calculations based on the Wess-Zumino-Witten effective Lagrangian. The hypothesis of chiral anomalies and the color-SU(3) quark symmetry are confirmed.
This paper is dedicated to the idea of studying in virtual worlds and discusses how virtual storytelling technology (VST) can provide an educational process. We try to answer the question -is it possible to substitute a real learning environment with a fully immersive 3D virtual space? And if so, what role should a virtual teacher play and what skills should he have? We describe several advantages that virtual environment (VE) has as compared to an ordinary classroom. It enables children to explore a phenomenon involved and gives them a strong incentive to study. Further, in VE we can transfer a lesson to inaccessible places and carry out demonstrations and experiments that are unrealizable on Earth. We consider the relationship between VST and game-like environments. We present some particular educational applications developed at our institute on the basis of Avango VR-system. Finally, we discuss the future of educational virtual environments and virtual storytelling.
In the course of monitoring interplanetary scintillations of a large number of sources using the Big Scanning Antenna of the Lebedev Physical Institute, a search for pulsars with periods ≥0.4 s at declinations −9◦ < δ < 42◦ and right ascensions 0h < α < 24h was simultaneously carried out. The search was conducted using four years of observations carried out at 110.25MHz in six frequency channels making up a 2.5 MHz band and having a time resolution of 100 ms. The initial identification of pulsar candidates was done using Fourier power spectra averaged over the entire observational period; the pulsar candidates were then verified using observations with higher frequency and time resolution: 32 frequency channels and a time resolution of 12.5 ms. Eighteen new pulsars were discovered in the studied area, whose main characteristics are presented
Summary. -Solutions of classical string theory, correspondent to the world sheets, mapped in Minkowsky space with a fold, are considered. Typical processes for them are creation of strings from vacuum, their recombination and annihilation. These solutions violate positiveness of square of mass and Regge condition. In quantum string theory these solutions correspond to physical states |DDF + |sp with nonzero spurious component.PACS 11.25 -theory of fundamental strings. PACS 11.27 -extended classical solutions.
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