152 research outputs found

    The Nature of Gamma-ray Bursts in the Framework of the Byuon Theory

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    Two models of gamma-ray bursts using the theory of byuons (TB) are considered. This theory describes a “life” of special unobservable discrete objects from which the surrounding space and the world of   ultimate particles are formed. Basic axioms and some conclusions of this theory are discussed. It is shown that basic problems with nature of gamma-rays bursts can be solved in the framework of this theory not only for bursts connected with supernova explosions but also for those without explosions

    Review of scientific topics for Millimetron space observatory

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    This paper describes outstanding issues in astrophysics and cosmology that can be solved by astronomical observations in a broad spectral range from far infrared to millimeter wavelengths. The discussed problems related to the formation of stars and planets, galaxies and the interstellar medium, studies of black holes and the development of the cosmological model can be addressed by the planned space observatory Millimetron (the "Spectr-M" project) equipped with a cooled 10-m mirror. Millimetron can operate both as a single-dish telescope and as a part of a space-ground interferometer with very long baseline.Comment: The translation of the original article in Physics Uspekhi http://ufn.ru/ru/articles/2014/12/c

    On the connection between gamma and radio radiation spectra in pulsars

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    The model of pulsar radio emission is discussed in which a coherent radio emis-sion is excited in a vacuum gap above polar cap of neutron star. Pulsar X and gamma radiation are considered as the result of low-frequency radio emission inverse Comp-ton scattering on ultra relativistic electrons accelerated in the gap. The influence of the pulsar magnetic field on Compton scattering is taken into account. The relation of radio and gamma radiation spectra has been found in the framework of the model.Comment: 15 pages, 3 figures, Russian version accepted to JETP, partly published in JETP Letters, Vol. 85, #6 (2007

    Microwave Photoconductivity in Two-Dimensional Electron Systems due to Photon-Assisted Interaction of Electrons with Leaky Interface Phonons

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    We calculate the contribution of the photon-assisted interaction of electrons with leaky interface phonons to the dissipative dc photoconductivity of a two-dimensional electron system in a magnetic field. The calculated photoconductivity as a function of the frequency of microwave radiation and the magnetic field exhibits pronounced oscillations. The obtained oscillation structure is different from that in the case of photon-assisted interaction with impurities. We demonstrate that at a sufficiently strong microwave radiation in the certain ranges of its frequency (or in certain ranges of the magnetic field) this mechanism can result in the absolute negative conductivity.Comment: 3 pages, 1 figur

    Absolute Negative Conductivity in Two-Dimensional Electron Systems Associated with Acoustic Scattering Stimulated by Microwave Radiation

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    We discuss the feasibility of absolute negative conductivity (ANC) in two-dimensional electron systems (2DES) stimulated by microwave radiation in transverse magnetic field. The mechanism of ANC under consideration is associated with the electron scattering on acoustic piezoelectric phonons accompanied by the absorption of microwave photons. It is demonstrated that the dissipative components of the 2DES dc conductivity can be negative (σxx=σyy<0\sigma_{xx} = \sigma_{yy} < 0) when the microwave frequency Ω\Omega is somewhat higher than the electron cyclotron frequency Ωc\Omega_c or its harmonics. The concept of ANC associated with such a scattering mechanism can be invoked to explain the nature of the occurrence of zero-resistance ``dissipationless'' states observed in recent experiments.Comment: 7 pager, 2 figure

    Nuclear Scissors Mode with Pairing

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    The coupled dynamics of the scissors mode and the isovector giant quadrupole resonance are studied using a generalized Wigner function moments method taking into account pair correlations. Equations of motion for angular momentum, quadrupole moment and other relevant collective variables are derived on the basis of the time dependent Hartree-Fock-Bogoliubov equations. Analytical expressions for energy centroids and transitions probabilities are found for the harmonic oscillator model with the quadrupole-quadrupole residual interaction and monopole pairing force. Deformation dependences of energies and B(M1)B(M1) values are correctly reproduced. The inclusion of pair correlations leads to a drastic improvement in the description of qualitative and quantitative characteristics of the scissors mode.Comment: 36 pages, 5 figures, the results of calculation by another method and the section concerning currents are adde
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