154 research outputs found
Determination of the UV cut-off from the observed value of the Universe acceleration
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
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
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
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)
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
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 Hamiltonian in the
vicinity of the 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
Comments on two papers by Kapusta and Wong
We critically examine recently published results on the thermal production of
massive vector bosons in a quark-gluon plasma. We claim the production rate is
a collinear safe observable.Comment: 6 pages LATEX documen
Energy and pressure densities of a hot quark-gluon plasma
We calculate the energy and hydrostatic pressure densities of a hot
quark-gluon plasma in thermal equilibrium through diagrammatic analyses of the
statistical average, , of the
energy-momentum-tensor operator . 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 .
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
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
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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