366 research outputs found
Two-loop corrections to false vacuum decay in scalar field theory
We consider radiative corrections to false vacuum decay in a four-dimensional
scalar field theory with cubic and quartic potential. Using planar thin wall
approximation we were able to get analytical expression for the decay rate up
to two loop order. The results obtained employ dimensional regularization and
renormalization scheme.Comment: 20 pages, 3 figures, clarifications adde
Non-planar elliptic vertex
We consider the problem of obtaining higher order in regularization parameter
analytical results for master integrals with elliptics. The two
commonly employed methods are provided by the use of differential equations and
direct integration of parametric representations in terms of iterated
integrals. Taking non-planar elliptic vertex as an example we show that in
addition to two mentioned methods one can use analytical solution of
differential equations in terms of power series. Moreover, in the last case it
is possible to obtain the exact in resultsComment: 26 pages, 4 figure
The Polish minority in the Republic of Lithuania: internal and external factors
The ethnic makeup of the population significantly affects the domestic policy of any state, and its relations with neighbouring countries. Although interactions with ethnic minorities are not as urgent a problem in Lithuania as they are in the two other Baltic States, ethnicity-related conflicts continue to occur, particularly, as regards the relations between the Lithuanian state and the Polish minority, which is the largest in the country. The Polish minority-Lithuania-Poland relations are not the only factor that affects the situation of the Poles in Lithuania. The other important factors are Lithuania and Poland' EU membership, the relations between Lithuania and Russia, and the Russian minority in Lithuania. Our analysis shows that the EU membership of Lithuania and Poland did not provide an instant solution to the problem of the Polish minority but rather attenuated it. Although the EU factor played a significant role before the accession of Poland and Lithuania to the Union, its influence is very limited today. The effect of the Russian factor is different. Strained Polish-Russian relations do not affect the relations between the Polish and Russian minorities in Lithuania. On the contrary, both minorities collaborate on a wide range of issues
A study of cell membranes in nasal epithelial cells from patients with chronic rhinosinusitis with nasal polyps by means of a fluorescent probe
Aim. To assess the state of membranes in nasal epithelial cells obtained from the patients with chronic rhinosinusitis with nasal polyps (CRSwNP) with the help of the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole. Methods. The state of membrane phospholipid bilayer in suspensions of nasal epithelial cells isolated from ten patients with CRSwNP was evaluated using the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole that reacts on the physico-chemical properties of its microenvironment. Changes in fluorescence spectra were determined using a Thermo Scientific Lumina fluorescence spectrometer (Thermo Fisher Scientific) 1 hour after the addition of the probe to nasal epithelial cell suspensions. Results. CRSwNP was found to be associated with a higher rate of nasal epithelial cell membrane hydration in the region of phospholipid glycerol moiety, carbonyl groups and aliphatic chains of fatty acids attached to the carbonyl groups. Conclusion. Our findings suggest that CRSwNP is accompanied by the elevated hydration rate of the most polar region, namely polar heads of phospholipids of nasal epithelial cell membranes
A study of cell membranes in nasal epithelial cells from patients with chronic rhinosinusitis with nasal polyps by means of a fluorescent probe
Aim. To assess the state of membranes in nasal epithelial cells obtained from the patients with chronic rhinosinusitis with nasal polyps (CRSwNP) with the help of the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole. Methods. The state of membrane phospholipid bilayer in suspensions of nasal epithelial cells isolated from ten patients with CRSwNP was evaluated using the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole that reacts on the physico-chemical properties of its microenvironment. Changes in fluorescence spectra were determined using a Thermo Scientific Lumina fluorescence spectrometer (Thermo Fisher Scientific) 1 hour after the addition of the probe to nasal epithelial cell suspensions. Results. CRSwNP was found to be associated with a higher rate of nasal epithelial cell membrane hydration in the region of phospholipid glycerol moiety, carbonyl groups and aliphatic chains of fatty acids attached to the carbonyl groups. Conclusion. Our findings suggest that CRSwNP is accompanied by the elevated hydration rate of the most polar region, namely polar heads of phospholipids of nasal epithelial cell membranes
Direct path from microscopic mechanics to Debye shielding, Landau damping, and wave-particle interaction
The derivation of Debye shielding and Landau damping from the -body
description of plasmas is performed directly by using Newton's second law for
the -body system. This is done in a few steps with elementary calculations
using standard tools of calculus, and no probabilistic setting. Unexpectedly,
Debye shielding is encountered together with Landau damping. This approach is
shown to be justified in the one-dimensional case when the number of particles
in a Debye sphere becomes large. The theory is extended to accommodate a
correct description of trapping and chaos due to Langmuir waves. Shielding and
collisional transport are found to be two related aspects of the repulsive
deflections of electrons, in such a way that each particle is shielded by all
other ones while keeping in uninterrupted motion.Comment: arXiv admin note: substantial text overlap with arXiv:1310.3096,
arXiv:1210.154
Rho-meson form factors and QCD sum rules
We present predictions for rho-meson form factors obtained from the analysis
of QCD sum rules in next-to-leading order of perturbation theory. The radiative
corrections turn out to be sizeable and should be taken into account in
rigorous theoretical analysis.Comment: LaTeX file, 14 pages, 7 figure
Special case of sunset: reduction and epsilon-expansion
We consider two loop sunset diagrams with two mass scales m and M at the
threshold and pseudotreshold that cannot be treated by earlier published
formula. The complete reduction to master integrals is given. The master
integrals are evaluated as series in ratio m/M and in epsilon with the help of
differential equation method. The rules of asymptotic expansion in the case
when q^2 is at the (pseudo)threshold are given.Comment: LaTeX, 13 pages, 1 figur
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