488 research outputs found
Conditions of Invertibility for Functional Operators with Shift in Weighted Hölder Spaces
We consider functional operators with shift in weighted Hölder spaces. The main result of the work is the proof of the conditions of invertibility for these operators. We also indicate the forms of the inverse operators. As an application, we propose to use these results for the solution of equations with shift encountered in the study of cyclic models for natural systems with renewable resources.Розглядаються функціональні оператори із зсувом у просторах Гельдера з вагою. Основним результатом роботи є встановлення умов оборотності для цих операторів. Вказано види оберненого оператора. Як застосування запропоновано використовувати отримані результати для розв'язання рівнянь із зсувом, які виникають при дослідженні циклічних моделей природних систем з ресурсами, що відновлюються
Purity-bounded uncertainty relations in multidimensional space -- generalized purity
Uncertainty relations for mixed quantum states (precisely, purity-bounded
position-momentum relations, developed by Bastiaans and then by Man'ko and
Dodonov) are studied in general multi-dimensional case. An expression for
family of mixed states at the lower bound of uncertainty relation is obtained.
It is shown, that in case of entropy-bounded uncertainty relations, lower-bound
state is thermal, and a transition from one-dimensional problem to
multi-dimensional one is trivial. Results of numerical calculation of the
relation lower bound for different types of generalized purity are presented.
Analytical expressions for general purity-bounded relations for highly mixed
states are obtained.Comment: 12 pages, 2 figures. draft version, to appear in J. Phys. A Partially
based on a poster "Multidimensional uncertainty relations for states with
given generalized purity" presented on X Intl. Conf. on Quantum Optics'2004
(Minsk, Belarus, May 30 -- June 3, 2004) More actual report is to be
presented on ICSSUR-2005, Besan\c{c}on, France and on EQEC'05, Munich. V. 5:
amended article after referees' remark
First steps to mapping of exoplanets: modeling secondary eclipses and search inhomogeneities in the infrared brightness profiles
С целью обнаружения неоднородностей собственного излучения экзопланеты HD209458b по наблюдениям космического телескопа Spitzer проведены обработка и моделирование кривых блеска вторичных транзитов (затмений). Работа является основой для последующего картирования распределения температуры на дневной стороне этой внесолнечной планеты. Неравномерность яркости вызвана звездно-планетными взаимодействиями, а также климатическими механизмами. Глубина затмения составила 0.101 ± 0.009% от общего блеска системы и согласуется с результатами других работ.To detect inhomogeneities in the thermal radiation of exoplanet HD209458b, based on observations of the Spitzer space telescope processing and modeling of the light curves of secondary transits (eclipses) were carried out. Current work is the basis for the mapping of the temperature distribution on the dayside of the exoplanet. Tidal and electromagnetic star-planet interactions, together with climate effects, lead to nonuniform heating of the surface. We obtained that the depth of the eclipse was 0.101±0.009% of the total flux of the system and is consistent with the results of other works
Revisiting the common envelope evolution in binary stars: a new semianalytic model for N -body and population synthesis codes
Stars and planetary system
Time dependence of the electron and positron components of the cosmic radiation measured by the PAMELA experiment between July 2006 and December 2015
Cosmic-ray electrons and positrons are a unique probe of the propagation of
cosmic rays as well as of the nature and distribution of particle sources in
our Galaxy. Recent measurements of these particles are challenging our basic
understanding of the mechanisms of production, acceleration and propagation of
cosmic rays. Particularly striking are the differences between the low energy
results collected by the space-borne PAMELA and AMS-02 experiments and older
measurements pointing to sign-charge dependence of the solar modulation of
cosmic-ray spectra. The PAMELA experiment has been measuring the time variation
of the positron and electron intensity at Earth from July 2006 to December 2015
covering the period for the minimum of solar cycle 23 (2006-2009) till the
middle of the maximum of solar cycle 24, through the polarity reversal of the
heliospheric magnetic field which took place between 2013 and 2014. The
positron to electron ratio measured in this time period clearly shows a
sign-charge dependence of the solar modulation introduced by particle drifts.
These results provide the first clear and continuous observation of how drift
effects on solar modulation have unfolded with time from solar minimum to solar
maximum and their dependence on the particle rigidity and the cyclic polarity
of the solar magnetic field.Comment: 11 pages, 2 figure
PAMELA Measurements of Cosmic-ray Proton and Helium Spectra
Protons and helium nuclei are the most abundant components of the cosmic
radiation. Precise measurements of their fluxes are needed to understand the
acceleration and subsequent propagation of cosmic rays in the Galaxy. We report
precision measurements of the proton and helium spectra in the rigidity range 1
GV-1.2 TV performed by the satellite-borne experiment PAMELA. We find that the
spectral shapes of these two species are different and cannot be well described
by a single power law. These data challenge the current paradigm of cosmic-ray
acceleration in supernova remnants followed by diffusive propagation in the
Galaxy. More complex processes of acceleration and propagation of cosmic rays
are required to explain the spectral structures observed in our data.Comment: 13 pages, 4 figures, link to SOM (with tables) in the references.
This manuscript has been accepted for publication in Science. This version
has not undergone final editing. Please refer to the complete version of
record at http://www.sciencemag.org/ [www.sciencemag.org
PAMELA's measurements of geomagnetic cutoff variations during solar energetic particle events
Data from the PAMELA satellite experiment were used to measure the
geomagnetic cutoff for high-energy ( 80 MeV) protons during the solar
particle events on 2006 December 13 and 14. The variations of the cutoff
latitude as a function of rigidity were studied on relatively short timescales,
corresponding to single spacecraft orbits (about 94 minutes). Estimated cutoff
values were cross-checked with those obtained by means of a trajectory tracing
approach based on dynamical empirical modeling of the Earth's magnetosphere. We
find significant variations in the cutoff latitude, with a maximum suppression
of about 6 deg for 80 MeV protons during the main phase of the storm. The
observed reduction in the geomagnetic shielding and its temporal evolution were
compared with the changes in the magnetosphere configuration, investigating the
role of IMF, solar wind and geomagnetic (Kp, Dst and Sym-H indexes) variables
and their correlation with PAMELA cutoff results.Comment: Conference: The 34th International Cosmic Ray Conference (ICRC2015),
30 July - 6 August, 2015, The Hague, The Netherlands, Volume:
PoS(ICRC2015)28
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