482 research outputs found

    Current status of cosmological MDM model

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    An analysis of cosmological models in spatially flat Friedmann Universe with cosmic gravitational wave background and zero Λ\Lambda-term is presented. The number of free parameters is equal to 5, they are σ8\sigma_8, nn, Ων\Omega_\nu, Ωb\Omega_b, and hh. The normalization of the spectrum of density perturbations on galaxy cluster abundance (σ8=0.52±0.04\sigma_8 = 0.52\pm 0.04) has been used to calculate numerically the value of the large scale CMB anisotropy (ℓ≃10\ell\simeq 10) and the relative contribution of cosmological gravitational waves T/S. Increasing Ων\Omega_\nu weaken the requirements to the value of T/S, however even for Ων≤0.4\Omega_\nu\le 0.4 the models with h+n≥1.5h+n\ge 1.5 suggest considerable abundance of gravitational waves: T/S∼>0.3{}^>_\sim 0.3. In models with Ων≤0.4\Omega_\nu\le 0.4 and scale-invariant spectrum of density perturbations (n=1n=1): T/S∼>10(h−0.47){}^>_\sim 10(h-0.47). Minimization of the value T/S is possible only in the range of the red spectra (n<1n<1) and small hh (<0.6<0.6). It is shown that the models with T/S∈[0,3]\in [0, 3] admit both moderate red and blue spectra of density perturbations, n∈[0.9,1.2]n\in[0.9,1.2], with rather high abundance hot dark matter, Ων∈[0.2,0.4]\Omega_\nu\in [0.2,0.4]. Any condition, n<0.9n<0.9 or Ων<0.2\Omega_\nu<0.2, decreases the relative amplitude of the first acoustic peak for more than 30% in comparison with its hight in the standard CDM normalized by COBE data.Comment: 4 pages, 2 figures included; contribution to the Proceedings of Moriond 2000 "Energy Densities in the Universe", Les Arcs, France, January 22-29 200

    EXPERIMENTAL DEMONSTRATION OF THE TIMEIRREVERSIBLE THERMAL EVOLUTION PROCESS AND SOME OF ITS CONSEQUENCES

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    Using a recently developed technique of synchronous differential temperature measurements (Titov &amp; Malinovsky 2005), the existence of the thermal surface energy (TSE) and of thermal hysteresis effect has been demonstrated in metallic gauge blocks (GB). The TSE (described here) is observed if there are inputs of energy and momentum of external electromagnetic (EM) field to material artefact and the heat source is not symmetrically located relative to the artefact surface. The TSE, linearly related to the Poynting vector of the EM field, presents the energy of the oriented motion of the coupled field-particles system inside artifacts. The TSE results in a thermal hysteresis effect, which is irreversible in time and has no symmetry in space. As the principle of superposition is shown not to be valid for EM fields in case of TSE, the hysteresis loop for the continuous sweep in time converts into a spiral, in which the form and the magnitude of the each cycle are slightly different from the ones of the adjacent cycles. In confirmation of the preceding theoretical result (Stroud et al 1972), the number of influence parameters in case of the field-particle system is found to be absolutely enormous, so that the thermal evolution process has, practically, infinite number of the existence and manifestation modes. Our studies present also an experimental confirmation of the basic results of the series of theoretical papers, initiated by R. H. Dicke (1954), in which the interaction of the ensemble of atoms with the electromagnetic field is analyzed

    DEMONSTRATION OF THE EXISTENCE OF THERMAL SURFACE ENERGY AND ITS IMPACTS

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    Using variation principle, we have demonstrated experimentally, for the first time, the existence of the thermal surface energy (TSE), resulting from the oriented motion of charged particles inside a material artefact and the energy of the guided electromagnetic (EM) field, which always accompanies the irregular motion of charged particles. The TSE arises gradually as an evolution process of hysteresis type as a result of interaction of the external EM field, characterized by a mean nonzero value of the Poynting vector, with an ensemble of charged particles of material artefact. It has been demonstrated experimentally that the principle of superposition of the external EM fields is not valid in case of TSE, and an artefact is shown to be in a continuous thermal evolution process, which has no symmetry in space and is irreversible in time, clearly confirming the preceding theoretical results of (Dicke 1954). Such process can be called as thermal synthesis. It is shown that the number of influence parameters, necessary for the description of the thermal evolution process is always huge, thus presenting an experimental confirmation of the fundamental theoretical observation of (Stroud et al. 1972, p.1096). We have shown experimentally for the first time that in a homogeneous material a heat source induces a larger flux of energy in a specified direction, if the energy flux in that direction has been created before by an auxiliary heat source. A deep agreement of our studies with Ancient Indian and Greek Philosophies, as well as with the classical German dialectics is outlined

    Prospects for observing supermassive black hole binaries with the space-ground interferometer

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    A list of candidates for \textit{supermassive binary black holes} (SMBBHs), compiled from available data on the variability in the optical range and the shape of the emission spectrum, is analysed. An artificial neural network is constructed to estimate the radiation flux at 240~GHz. For those candidate SMBBH for which the network building procedure was feasible, the criterion of the possibility of observing the source at the \textit{Millimetron Space Observatory} (MSO) was tested. The result is presented as a table of 17 candidate SMBBHs. Confirmation (or refutation) of the duality of these objects by means of observational data which could be commited on a space-ground interferometer with parameters similar to those of the MSO will be an important milestone in the development of the theory of galaxy formation.Comment: 15 pages, 6 figures, 2 table, accepted for publication in Astronomy Report

    Structural investigation of twinned crystals

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