154 research outputs found

    Determination of the UV cut-off from the observed value of the Universe acceleration

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    It is shown that using of the equation of motion of the Universe scale factor allows calculation of the contribution of the vacuum fluctuations to the acceleration of the Universe expansion. Renormalization of the equation is needed only in the case of massive particles. Under a known number of the different kinds of fundamental fields, this provides determination of momentum of the ultraviolet cut-off from the observed value of acceleration.Comment: 10 pages, 1 figur

    Socio-economic features of the regions as a fundamental factor in their long-term development

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    The paper highlights the features of the regions depending on three areas: budgetary, social, and economic. These areas are analyzed using the example of the Central Federal District of Russi

    Non-Analytic Vertex Renormalization of a Bose Gas at Finite Temperature

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    We derive the flow equations for the symmetry unbroken phase of a dilute 3-dimensional Bose gas. We point out that the flow equation for the interaction contains parts which are non-analytic at the origin of the frequency-momentum space. We examine the way this non-analyticity affects the fixed point of the system of the flow equations and shifts the value of the critical exponent for the correlation length closer to the experimental result in comparison with previous work where the non-analyticity was neglected. Finally, we emphasize the purely thermal nature of this non-analytic behaviour comparing our approach to a previous work where non-analyticity was studied in the context of renormalization at zero temperature.Comment: 21 pages, 4 figure

    Advances in perturbative thermal field theory

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    The progress of the last decade in perturbative quantum field theory at high temperature and density made possible by the use of effective field theories and hard-thermal/dense-loop resummations in ultrarelativistic gauge theories is reviewed. The relevant methods are discussed in field theoretical models from simple scalar theories to non-Abelian gauge theories including gravity. In the simpler models, the aim is to give a pedagogical account of some of the relevant problems and their resolution, while in the more complicated but also more interesting models such as quantum chromodynamics, a summary of the results obtained so far are given together with references to a few most recent developments and open problems.Comment: 84 pages, 18 figues, review article submitted to Reports on Progress in Physics; v2, v3: minor additions and corrections, more reference

    Epidemiology of cardiovascular diseases among patients with diabetes mellitus according to the federal diabetes register of the Russian Federation (2013–2016)

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    BACKGROUND: Cardiovascular diseases (CVD) are the main cause of death for patients with diabetes mellitus (DM). AIMS: To evaluate the CVD epidemiology: coronary heart disease (CHD), myocardial infarction (MI) and cerebrovascular diseases in adult patients with type 1 (T1DM) and type 2 (T2DM) diabetes, compare dynamics with data of implementation of the Federal Program «Diabetes mellitus» in 2007–2012 and over the online period 2013–2016. MATERIALS AND METHODS: The database of the Federal Diabetes register (81 regions at 12.2017). We estimated prevalence and incidence rates/10 thousand (th) adult DM patients over 18 years. RESULTS: The prevalence of CVD for the period 2007 – 2016 significant decreased in CHD for T1DM from 14,9% to 3,5%, for T2DM from 20,1% to 11,7%; MI for T1DM from 5,7% to 1,3%, for T2DM from 7,6% to 3,5%; cerebrovascular diseases for T1DM from 4,9% to 1,7%, for T2DM from 7,6% to 4,3%, respectively. In 2013→2016 positive trends continued: MI for T1DM 8,2→5,9/10th patients, for T2DM 19,2→14,7/10th patients, respectively; CVD for T1DM 11,3→10,5, for T2DM 29,4→25,4/10th patients, respectively. There was a large heterogeneity of the prevalence of CVD in the regions. MI varied in patients for T1DM from 319/10 th patients to absence, for T2DM from 800 to 7/10 th patients; the development of cerebrovascular diseases for T2DM from 900 to less than 100/10 th patients, which is largely due to differences in their registration. A small number of cases may be due to insufficient filling of the database, the facts of a huge number require further analysis. The average age of development of MI had increased: for T1DM 51,2→53 years, for T2DM 63,5→65 years, cerebrovascular diseases for T1DM 52,3→52.5 years, for T2DM 65,2→66,5, respectively. CONCLUSIONS: The prevalence of CVD significantly decreased in the Russian Federation compared to 2007–2012, as well as for the period 2013–2016: the prevalence of CHD and cerebrovascular diseases declined, the number of new cases of MI decreased, the average age and duration of DM before the development of CVD significantly increased. These data reflect the results of the program for improvement medical care and prevention measures for patients with diabetes

    Intrinsic Spin Lifetime of Conduction Electrons in Germanium

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    We investigate the intrinsic spin relaxation of conduction electrons in germanium due to electron-phonon scattering. We derive intravalley and intervalley spin-flip matrix elements for a general spin orientation and quantify the resulting anisotropy in spin relaxation. The form of the intravalley spin-flip matrix element is derived from the eigenstates of a compact spin-dependent k\mathbf{k}\cdotp\mathbf{p} Hamiltonian in the vicinity of the LL point (where thermal electrons are populated in Ge). Spin lifetimes from analytical integrations of the intravalley and intervalley matrix elements show excellent agreement with independent results from elaborate numerical methods.Comment: 13 pages, 2 figure

    Energy and pressure densities of a hot quark-gluon plasma

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    We calculate the energy and hydrostatic pressure densities of a hot quark-gluon plasma in thermal equilibrium through diagrammatic analyses of the statistical average, Θμν\langle \Theta_{\mu \nu} \rangle, of the energy-momentum-tensor operator Θμν\Theta_{\mu \nu}. To leading order at high temperature, the energy density of the long wave length modes is consistently extracted by applying the hard-thermal-loop resummation scheme to the operator-inserted no-leg thermal amplitudes Θμν\langle \Theta_{\mu \nu} \rangle. We find that, for the long wave length gluons, the energy density, being positive, is tremendously enhanced as compared to the noninteracting case, while, for the quarks, no noticeable deviation from the noninteracting case is found.Comment: 33 pages. Figures are not include

    FEATURES OF CMOS MICROCIRCUITS X-RAY IRRADIATION TESTING

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    The paper substantiates the possibility of X-ray sources usage in radiation-hardness tests of microcircuits with 180 nm design or less. The tests were conducted using an electron ac-celerator in bremsstrahlung mode and an X-ray unit. The comparison results and key features are presented.Авторы выражают благодарность Смолину А.С. и Демидову А.А. из АО «ЭНПО СПЭЛС» за полезные обсуждения и рекомендации при подготовке материала

    Coronal Shock Waves, EUV waves, and Their Relation to CMEs. I. Reconciliation of "EIT waves", Type II Radio Bursts, and Leading Edges of CMEs

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    We show examples of excitation of coronal waves by flare-related abrupt eruptions of magnetic rope structures. The waves presumably rapidly steepened into shocks and freely propagated afterwards like decelerating blast waves that showed up as Moreton waves and EUV waves. We propose a simple quantitative description for such shock waves to reconcile their observed propagation with drift rates of metric type II bursts and kinematics of leading edges of coronal mass ejections (CMEs). Taking account of different plasma density falloffs for propagation of a wave up and along the solar surface, we demonstrate a close correspondence between drift rates of type II bursts and speeds of EUV waves, Moreton waves, and CMEs observed in a few known events.Comment: 30 pages, 15 figures. Solar Physics, published online. The final publication is available at http://www.springerlink.co
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