2,124 research outputs found
Preserving the measure of compatibility between quantum states
In this paper after defining the abstract concept of compatibility-like
functions on quantum states, we prove that every bijective transformation on
the set of all states which preserves such a function is implemented by an
either unitary or antiunitary operator.Comment: 11 pages, submitted for publicatio
Uniqueness of the electrostatic solution in Schwarzschild space
In this Brief Report we give the proof that the solution of any static test
charge distribution in Schwarzschild space is unique. In order to give the
proof we derive the first Green's identity written with p-forms on (pseudo)
Riemannian manifolds. Moreover, the proof of uniqueness can be shown for either
any purely electric or purely magnetic field configuration. The spacetime
geometry is not crucial for the proof.Comment: 3 pages, no figures, uses revtex4 style file
Bjorken hydrodynamics and gradual freeze out
The freeze out of the expanding systems, created in relativistic heavy ion collisions, is discussed. We combine kinetic freeze out equations with Bjorken type system expansion into a unified model. The important feature of the proposed scenario is that physical freeze out is completely finished in a finite time, which can be varied from 0 (freeze out hypersurface) to infinit. The dependence of the post freeze out distribution function on the freeze out time will be studied. Model allows analytical analyses for the simplest systems such as pion gas. We shall see that the basic freeze out features, pointed out in the earlier works, are not smeared out by the expansion of the system. The entropy evolution in such a scenario is also studied
Freeze out of the expanding system
The freeze out (FO) of the expanding systems, created in relativistic heavy
ion collisions, is discussed. We start with kinetic FO model, which realizes
complete physical FO in a layer of given thickness, and then combine our
gradual FO equations with Bjorken type system expansion into a unified model.
We shall see that the basic FO features, pointed out in the earlier works, are
not smeared out by the expansion.Comment: 3 pages, 2 figure
A modulated RRd star observed by K2
We report the analysis of the double-mode RR Lyrae star EPIC 205209951, the
first modulated RRd star observed from space. The amplitude and phase
modulation are present in both modes.Comment: 2 pages, 3 figures, proceedings of the Joint
TASC2-KASC9-SPACEINN-HELAS8 Conference "Seismology of the Sun and the Distant
Stars 2016", to be published in EPJ Wo
Finite hadronization time and unitarity in quark recombination model
The effect of finite hadronization time is considered in the recombination
model, and it is shown that the hadron multiplicity turns out to be
proportional to the initial quark density and unitarity is conserved in the
model. The baryon to meson ratio increases rapidly with the initial quark
density due to competition among different channels.Comment: 4 pages in RevTeX, 3 eps figures, to appear in J. Phys.G as a lette
Spin-dependent transmission through a chain of rings: influence of a periodically modulated spin-orbit interaction strength or ring radius
We study ballistic electron transport through a finite chain of quantum
circular rings in the presence of spin-orbit interaction of strength \alpha.
For a single ring the transmission and reflection coefficients are obtained
analytically and from them the conductance for a chain of rings as a function
of \alpha and of the wave vector k of the incident electron. We show that due
to destructive spin interferences the chain can be totaly opaque for certain
ranges of k the width of which depends on the value of \alpha. A periodic
modulation of the strength \alpha or of the ring radius widens up the gaps
considerably and produces a nearly binary conductance output.Comment: 4 pages, 4 figures. Appl. Phys. Lett., in pres
Selection of winter cereals for organic agriculture
Productivity in agriculture has more than tripled in developed countries since the 1950s. Beyond the success of plant breeding, the increased use of inorganic fertilizers, application of pesticides, and spread of irrigation also contributed to this success. However, impressive yield increases started to decline in the 1980s because of the lack of sustainability.
One of the most beneficial ways to increase sustainability is organic agriculture. In such systems the prerequisite of successful farming is the availability of crop genotypes that perform well. However, selection of winter cereals for sub-optimal growing conditions is still neglected, and the organic seed market also lacks of information on credibly tested varieties suitable for organic agriculture
Freeze Out Process with In-Medium Nucleon Mass
We investigate the kinetic freeze out scenario of a nucleon gas through a
finite layer. The in-medium mass modification of nucleons and it's impact on
the freeze out process is studied. A considerable modification of the
thermodynamical parameters temperature, flow-velocity, energy density and
particle density has been found in comparison with evaluations which use a
constant vacuum nucleon mass.Comment: 6 pages, 4 figures, Proceeding of the Conference "Quark Matter 2005",
4th - 9th August 2005, Budapest/Hungar
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