137 research outputs found
Dirac quantization of free motion on curved surfaces
We give an explicit operator realization of Dirac quantization of free
particle motion on a surface of codimension 1. It is shown that the Dirac
recipe is ambiguous and a natural way of fixing this problem is proposed. We
also introduce a modification of Dirac procedure which yields zero quantum
potential. Some problems of abelian conversion quantization are pointed out.Comment: 16 page
Discovering the Far East...’: Images of the Territory in the Works of V. K. Arsenyev
The article explores the works of the Far East explorer V.K. Arsenyev (1872–1930) with the purpose of using his works to find the representational potential of the region’s image. Using social constructivism as a methodology, we outline and analyze scientific and artistic types of constructing the Far East image and demonstrate the place each of these types occupies in Arsenyev’s works.
Keywords: regional image, constructivism, construct, visualization, Russian Far East, V.K.Arsenye
A live border: cossack maneuvers in the context of colonization (the late sixteenth to the early seventeenth century) = Живая граница: казачьи маневры в пространстве колонизации (рубеж XVI-XVII вв.)
The Cossacks personified a "live border" in the southern Russian periphery (Ukraina), one that maneuvered between the Muscovite state, the Polish-Lithuanian Commonwealth, the Crimean Khanate, and the Nogai Hord
Gravitational Waves in New General Relativity
The models of New General Relativity have recently got attention of research
community, and there are some works studying their dynamical properties. The
formal aspects of this investigation have been mostly restricted to the primary
constraints in the Hamiltonian analysis. However, it is by far not enough for
counting their degrees of freedom or judging whether they are any good and
viable. In this paper we study linearised equations in vacuum around the
trivial Minkowski tetrad. By taking the approach of cosmological perturbation
theory we show that the numbers of primary constraints are very easily seen
without any need of genuine Hamiltonian techniques, and give the full count of
linearised degrees of freedom in the weak field limit of each and every version
of New General Relativity without matter.Comment: 14 page
TO THE SELECTION OF BONE CAVITY FILLING MATERIAL FOR PATIENTS WITH CHRONIC OSTEOMYELITIS
The research covered 83 patients with chronic osteomyelitis, 55 patients underwent the original operation of single stage sequestrectomy and grafting the residual bone cavity with fine-grain titanium nickelide. This method of treatment has demonstrated its effectiveness in the early rehabilitation period, as well as in the observation in a remote period of time. Clinical effects were characterized by the absence of relapses of chronic osteomyelitis in 94.6 % of patients during the follow-up period. The simulating effect of titanium nickelide in the formation of trabecular bone tissue was experimentally based on 20 animals (dogs). Thus, clinic-experimental research showed that porous titanium nickelide is a perspective material and can be used for different skeletal pathologies. Using it as bone cavity filling in the experiment resulted in an accelerated (3 months earlier) formation of bone organotypic regenerate. The use of bio-compatible fine-grain titanium nickelide contributes into rapid and efficient completion of inflammation process in bone tissue, simplifies the methodology, reduces the time of operation and the time of rehabilitation period and, as a result, increases the efficiency of treating patients with chronic osteomyelitis
Soviet Anti-religious Film. “Sectarians” by Vladimir Korolevich (1930)
The article examines a unique phenomenon of Soviet cinema – the anti-religious film of the 1920s–1930s – a question insufficiently explored in humanitarian historiography so far. Being an organic part of the “cultural revolution”, on the one hand, anti-religious films of this period acted as an effective tool for the propaganda of the Soviet state in the fight against both the official church and manifestations of everyday religiosity. On the other hand, their creation was accompanied by detailed theoretical and methodological recommendations on the forms of interaction of party propagandists with the audience, and on the formats for the presentation of anti-religious attitudes. Based on previously unpublished archival materials, the authors bring to the fore one of the most indicative of such films titled “Sectarians” shoot by Vladimir Korolevich (Sovkino, 1930). The authors consider the film as a document of that time and analyze processes that ran parallel with one another in the Soviet culture and policy. Taking the film “Sectarians” as a case-study, the authors explore cinematic methods of constructing a negative image of sectarian organizations in the USSR and its broadcast to a wide audience in ideological way. The authors came to the conclusion that the Soviet anti-religious cinema, combining the techniques of avant-garde cinematography and scientific atheism, successfully fulfilled its propaganda mission. In this context, the film “Sectarians” is a valuable historical source, that represented the contradictory phenomena of its time and was aimed at the visual reconstruction of “Sovietness” as a new religion. © 2021, Amur State University. All rights reserved.This research was supported by the Russian Science Foundation (RSF) as a part of the project № 21-18-00518, https://rscf.ru/en/project/21-18-00518/
What-if inflaton is a spinor condensate?
In the usual cosmological inflationary scenarios, the scalar field --
inflaton -- is usually assumed to be an elementary field. In this essay, we
ask: What are the observational signatures, if the scalar field is a spinor
condensate? and Is there a way to distinguish between the canonical scalar
field and the spinor condensate driven models? In the homogeneous and isotropic
background, we show that, although the dark-spinor (Elko) condensate leads to
the identical acceleration equation as that of the canonical scalar field
driven inflation, the dynamics of the two models are different. In the
slow-roll limit, we show that the model, predicts a running of scalar spectral
index consistent with the WMAP data. We show that the consistency relations
between the spinor condensate and canonical scalar field driven model are
different which can be tested using the future CMB and gravitational wave
missions.Comment: 8 Pages, This essay received an honorable mention from the Gravity
Research Foundation essay competition in 2009; Typos corrected, to appear in
IJMP
Initial Conditions for Vector Inflation
Recently, a model of inflation using non-minimally coupled massive vector
fields has been proposed. For a particular choice of non-minimal coupling
parameter and for a flat FRW model, the model is reduced to the model of
chaotic inflation with massive scalar field. We study the effect of non-zero
curvature of the universe on the onset of vector inflation. We find that in a
curved universe the dynamics of vector inflation can be different from chaotic
inflation, and the fraction of the initial conditions leading to inflationary
solutions is reduced compared with the chaotic inflation case.Comment: 12 pages, 5 figures, version to be published in JCA
On the Weyl - Eddington - Einstein affine gravity in the context of modern cosmology
We propose new models of an `affine' theory of gravity in -dimensional
space-times with symmetric connections. They are based on ideas of Weyl,
Eddington and Einstein and, in particular, on Einstein's proposal to specify
the space - time geometry by use of the Hamilton principle. More specifically,
the connection coefficients are derived by varying a `geometric' Lagrangian
that is supposed to be an arbitrary function of the generalized (non-symmetric)
Ricci curvature tensor (and, possibly, of other fundamental tensors) expressed
in terms of the connection coefficients regarded as independent variables. In
addition to the standard Einstein gravity, such a theory predicts dark energy
(the cosmological constant, in the first approximation), a neutral massive (or,
tachyonic) vector field, and massive (or, tachyonic) scalar fields. These
fields couple only to gravity and may generate dark matter and/or inflation.
The masses (real or imaginary) have geometric origin and one cannot avoid their
appearance in any concrete model. Further details of the theory - such as the
nature of the vector and scalar fields that can describe massive particles,
tachyons, or even `phantoms' - depend on the concrete choice of the geometric
Lagrangian. In `natural' geometric theories, which are discussed here, dark
energy is also unavoidable. Main parameters - mass, cosmological constant,
possible dimensionless constants - cannot be predicted, but, in the framework
of modern `multiverse' ideology, this is rather a virtue than a drawback of the
theory. To better understand possible applications of the theory we discuss
some further extensions of the affine models and analyze in more detail
approximate (`physical') Lagrangians that can be applied to cosmology of the
early Universe.Comment: 15 pages; a few misprints corrected, one footnote removed and two
added, the formulae and results unchanged but the text somewhat edited, esp.
in Sections 4,5; the reference to the RFBR grant corrected
Molecular dynamics study of cluster structure and properties of rotational waves in solid nanostructures
The paper reports a molecular dynamics analysis of rotary properties of a transformational wave generated due to compressive influence. Studies are performed in the time interval prior to the onset of elastic precursor reflection from the free boundary. It is shown that the leading front of a rotary wave coincides with the transformational wave front. The rotary wave velocity for copper is determined, being equal to 1300 m/s. The values of angular moment projections onto the coordinate axes in a plane perpendicular to wave propagation are found to be symmetrical, and their total sum equals zero
- …