12,655 research outputs found
Ідентичність людини в сучасних умовах: роздуми над ціннісними пріоритетами екзистенціальної теології Дж. Маккуорі. (Identity of man in modern terms: reflections on the value priorities of existential theology of J. MacQuarrie.)
У статті розкривається проблема інтерпретації Дж. Маккуоррі ціннісних підвалин християнства відповідно до вимог сучасної реальності. Аналізується питання подолання кризи релігійної ідентичності людини, якому присвячена
праця філософа “Принципи християнської теології”. Досліджується специфіка синтезу екзистенціалізму та теології.
(The article deals with the problem of interpretation J. MacQuarrie value foundations of Christianity, according to
today’s reality. Examines the question of overcoming the crisis of religious identity of the person is devoted to the philosopher,
“Principles of Christian Theology”. We investigate the specificity of the synthesis of existentialism and theology.
UBVR observation of V1357 Cyg = Cyg X-1. Search of the optical radiation of the accretion disk
Data from 30 nights of V 1357 Cyg observations in July, August, and September of 1977 are presented. The contribution of the disk to the optic brightness of the system is computed with regard for the heating of its surface by ultraviolet radiation from V 1357 Cyg and X-ray radiation from Cyg X-1. The disk radiation explains the irregular variability in the system brightness. The possibility of the eclipse of the star by the disk and the disk by the star is discussed
Relaxation of superflow in a network: an application to the dislocation model of supersolidity of helium crystals
We have considered the dislocation network model for the supersolid state in
He-4 crystals. In difference with uniform 2D and 3D systems, the temperature of
superfluid transition T_c in the network is much smaller than the degeneracy
temperature T_d. It is shown that a crossover into a quasi superfluid state
occurs in the temperature interval between T_c and T_d. Below the crossover
temperature the time of decay of the flow increases exponentially under
decrease of the temperature. The crossover has a continuous character and the
crossover temperature does not depend on the density of dislocations.Comment: Corrected typo
On the dipole moment of quantized vortices generated by flows
The polarization charge of an inhomogeneous superfluid system is
expressed as a function of the order parameter . It is shown that if the order
parameter changes on macroscopic distances, the polarization charge is proportional to , and the polarization
is proportional to , where is the density of the
system. For noninteracting atoms the proportionality coefficient is
independent of density, and in the presence of interaction is proportional
to . The change of the Bose gas density is found in the presence of a flow
passing the vortex. It is
found that a vortex in a superfluid film creates an electric potential above
the film. This potential has the form of a potential of a dipole, allowing to
assign a dipole moment to the vortex. The dipole moment is a sum of two terms,
the first one is proportional to the relative flow velocity and
the second one is proportional to , where is the vortex circulation.Comment: 6 page
Vortex generation in a superfluid gas of dipolar chains in crossed electric and magnetic fields
Crossed electric and magnetic fields influence dipolar neutral particles in
the same way as the magnetic field influences charged particles. The effect of
crossed fields is proportional to the dipole moment of the particle (inherent
or induced). We show that this effect is quite spectacular in a multilayer
system of polar molecules. In this system molecules may bind in chains. At low
temperature the gas of chains becomes the superfluid one. The crossed fields
then induce vortices in the superfluid gas of chains. The density of vortices
is proportional to the number of particles in the chain. The effect can be used
for monitoring the formation and destruction of chains in multilayer dipolar
gases.Comment: To appear in Low Temperature Physics/Fizika Nizkikh Temperatur, 2020,
v. 46, No.
Impact of the transport supercurrent on the Josephson effect
We study the weak link between current-carrying superconductors, both
conventional and d-wave. The state of the system is controlled by two
parameters: the order parameter phase difference and the superfluid
velocity , which parameterizes the parallel to the boundary transport
supercurrent which is injected externally. The low-temperature current-phase
relations are derived. We consider two models of weak links: a constriction
between two conventional superconductors and a plane boundary between two
differently orientated d-wave superconductors. We show that for some relation
between and quasiparticles create the current along the
boundary which flows in the direction opposite to the transport supercurrent.Comment: 5 pages, 3 figures; submitted for publication in Proceedings of
MS+S2004 symposium (without Sec.V and the last part of Sec.III
Vortex matter and generalizations of dipolar superfluidity concept in layered systems
In the first part of this letter we discuss electrodynamics of an excitonic
condensate in a bilayer. We show that under certain conditions the system has a
dominant energy scale and is described by the effective electrodynamics with
"planar magnetic charges". In the second part of the paper we point out that a
vortex liquid state in bilayer superconductors also possesses dipolar
superfluid modes and establish equivalence mapping between this state and a
dipolar excitonic condensate. We point out that a vortex liquid state in an
N-layer superconductor possesses multiple topologically coupled dipolar
superfluid modes and therefore represents a generalization of the dipolar
superfluidity concept.Comment: v2: references added. v3: discussion extended, references adde
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