1,446 research outputs found
On the radiative lifetime of free-moving two-dimensional excitons
A simple microscopic mechanism explaining the linear dependence of the
radiative lifetime of free-moving two-dimensional excitons on their effective
temperature is suggested. It is shown that there exists a characteristic
effective temperature (of about few Kelvin) defined by the exciton-acoustic
phonon interaction at which the radiative lifetime is minimal. Below this
temperature the lifetime starts to increase with decreasing temperature. The
correspondence with previous theoretical and experimental results is discussed.Comment: 5 pages, 3 figures. Final versio
Asymptotic properties of Lp-estimators
Some sufficient conditions for consistency and asymptotic normality of a non-linear regression parameter Lp-estimator are presented for a continuous time regression model with Gaussian stationary noise possessing the long-range dependence or weak dependence property
Суспільно-політична та культурно-просвітницька діяльність наукових осередків української діаспори в США
Досліджується та аналізується питання діяльності українських наукових осередків на території США. Особливу увагу приділено головним центрам науки української діаспори, а саме: Науковому товариству ім. Т. Шевченка, Українській вільній академії наук та Українському інституту Америки.The activity of Ukrainian scientific center on the area of U.S.A. is explorer and analyzed. The special attention is considered on three main centre of science of Ukrainian. Diaspora, and exactly on Scientific Society of name T. Shevchenko, Ukrainian free academy of science and Ukrainian institute of America
Conformal properties of hypermultiplet actions in six dimensions
We consider scale-invariant interactions of 6D N=1 hypermultiplets with the
gauge multiplet. If the canonical dimension of the matter scalar field is
assumed to be 1, scale-invariant lagrangians involve higher derivatives in the
action. Though scale-invariant, all such lagrangians are not invariant with
respect to special conformal transformations and their superpartners. If the
scalar canonical dimension is assumed to be 2, conformal invariance holds at
the classical, but not at the quantum level.Comment: 14 pages, 1 figur
Nonlocal field correlators on the lattice in HP^1 sigma-model
Connected two-point field strength correlators have been measured on the
lattice in quaternionic projective sigma-model of pure SU(2) Yang-Mills theory.
The correlation lengths, extracted from the exponential fit for these
correlators, are found to be lambda_1^{-1} = 1.40(3) GeV and lambda^{-1} =
1.51(3) GeV in good agreement with other existing calculations. The dependence
of bilocal functions on the connector shape was studied.Comment: 11 pages, 9 figures, to be published in JETP Letter
Роль очагов инфекции при различных кожных заболеваниях
Reviewed scientific publications that define the location of foci of chronic infections in dermatology. Indicated by the currently existing problematic issues and their solutions.Проанализированы научные публикации, определяющие место очагов хронической инфекции в дерматологии. Обозначены существующие на данный момент проблемные вопросы и пути их решения
Chiral anomalies in higher-derivative supersymmetric 6D gauge theories
We show that the recently constructed higher-derivative 6D SYM theory
involves an internal chiral anomaly breaking gauge invariance. The anomaly is
cancelled when adding to the theory an adjoint matter hypermultiplet.Comment: A missed contribution added. The article is rather essentially
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Parameter estimators of nonlinear quantile regression
We have obtained the asymptotic normality of parameter estimators of a nonlinear
quantile regression with nonsymmetric random noise
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