8,398 research outputs found
"Minus c" Symmetry in Classical and Quantum Theories
It is shown that the transformations of the charge conjugation in classical
electrodynamics and in quantum theory can be interpreted as the consequences of
the symmetry of Maxwell and Dirac equations with respect to the inversion of
the speed of light: c to -c; t to t; (x,y,z) to (x,y,z), where c is the speed
of light; t is the time; x, y, z are the spatial variables.
The elements of physical interpretation are given.Comment: 12 pages, LaTeX, Poster at the Fifth International Conference on
Squeezed States and Uncertainty Relations, May 27-31, 1997, Balatonfured,
Hungar
Trauma histories of men and women in residential drug treatment: The Scottish evidence
This article focuses on self-reported child neglect and abuse in residential drug treatment drawing on data from clients in Scotland collected 1996-1999. It notes the lack of adoption of regular screening using validated tools of childhood trauma in men and women. The authors’ findings suggest that the prevalence of childhood abuse histories are higher in female drug users than male drug users but recognises that even with standardised tools there is a wealth of diverse categories of severity of abuse that warn against broad treatment plans for ‘the traumatised’
A Pulsational Model for the Orthogonal Polarization Modes in Radio Pulsars
In an earlier paper, we introduced a model for pulsars in which non-radial
oscillations of high spherical degree (\el) aligned to the magnetic axis of a
spinning neutron star were able to reproduce subpulses like those observed in
single-pulse measurements of pulsar intensity. The model did not address
polarization, which is an integral part of pulsar emission. Observations show
that many pulsars emit radio waves that appear to be the superposition of two
linearly polarized emission modes with orthogonal polarization angles. In this
paper, we extend our model to incorporate linear polarization. As before, we
propose that pulsational displacements of stellar material modulate the pulsar
emission, but now we apply this modulation to a linearly-polarized mode of
emission, as might be produced by curvature radiation. We further introduce a
second polarization mode, orthogonal to the first, that is modulated by
pulsational velocities. We combine these modes in superposition to model the
observed Stokes parameters in radio pulsars.Comment: 19 pages, 4 figures accepted Ap
Higher order effects in the and transfer reactions
Full Coupled Channels Calculations were performed for the
and transfer reactions at several deuteron incident
energies from MeV up to 3.27 MeV. A strong polarization effect
between the entrance channel and the transfer channels
and was
observed. This polarization effect had to be taken into account in order to
obtain realistic spectroscopic factors from these reactions.Comment: 15 papes, 13 figures, accepted for publication in Phys. Rev.
V405 Aurigae: A High Magnetic Field Intermediate Polar
Our simultaneous multicolor (UBVRI) circular polarimetry has revealed nearly
sinusoidal variation over the WD spin cycle, and almost symmetric positive and
negative polarization excursions. Maximum amplitudes are observed in the B and
V bands (+-3 %). This is the first time that polarization peaking in the blue
has been discovered in an IP, and suggests that V405 Aur is the highest
magnetic field IP found so far. The polarized flux spectrum is similar to those
found in polars with magnetic fields in the range B ~ 25-50 MG. Our low
resolution circular spectropolarimetry has given evidence of transient features
which can be fitted by cyclotron harmonics n = 6, 7, and 8, at a field of B =
31.5 +- 0.8 MG, consistent with the broad-band polarized flux spectrum. Timings
of the circular polarization zero crossovers put strict upper limits on WD spin
period changes and indicate that the WD in V405 Aur is currently accreting
closely at the spin equilibrium rate, with very long synchronization
timescales, T_s > 10^9 yr. For the observed spin to orbital period ratio,
P_{spin}/P_{orb} = 0.0365, and P_{orb} ~ 4.15 hr, existing numerical accretion
models predict spin equilibrium condition with B ~ 30 MG if the mass ratio of
the binary components is q_1 ~ 0.4. The high magnetic field makes V405 Aur a
likely candidate as a progenitor of a polar.Comment: To appear in The Astrophysical Journal, September 1 Issue (2008), 9
pages, 10 figure
Uniformizing the Stacks of Abelian Sheaves
Elliptic sheaves (which are related to Drinfeld modules) were introduced by
Drinfeld and further studied by Laumon--Rapoport--Stuhler and others. They can
be viewed as function field analogues of elliptic curves and hence are objects
"of dimension 1". Their higher dimensional generalisations are called abelian
sheaves. In the analogy between function fields and number fields, abelian
sheaves are counterparts of abelian varieties. In this article we study the
moduli spaces of abelian sheaves and prove that they are algebraic stacks. We
further transfer results of Cerednik--Drinfeld and Rapoport--Zink on the
uniformization of Shimura varieties to the setting of abelian sheaves. Actually
the analogy of the Cerednik--Drinfeld uniformization is nothing but the
uniformization of the moduli schemes of Drinfeld modules by the Drinfeld upper
half space. Our results generalise this uniformization. The proof closely
follows the ideas of Rapoport--Zink. In particular, analogies of -divisible
groups play an important role. As a crucial intermediate step we prove that in
a family of abelian sheaves with good reduction at infinity, the set of points
where the abelian sheaf is uniformizable in the sense of Anderson, is formally
closed.Comment: Final version, appears in "Number Fields and Function Fields - Two
Parallel Worlds", Papers from the 4th Conference held on Texel Island, April
2004, edited by G. van der Geer, B. Moonen, R. Schoo
The ways of solving the problems of financing energy saving measures in organizations of budgetary sphere of Ukraine
Проведено аналіз публікацій щодо потенціалу енергозбереження в Україні. Показано проблеми фінансування бюджетної сфери на потреби тепло забезпечення. Показано проблему нормування витрат теплової енергії. Подано опис недосконалості сучасних вимог щодо опору теплопередачі огороджувальних конструкцій. Показано вимоги щодо опору теплопередачі огороджувальних конструкцій деяких іноземних держав. Показано необхідність застосування статистично-математичних методів для підвищення рівня якості процесу аналізу витрат на споживання теплової енергії у будівлях бюджетної сфери України. Запропоновано методи визначення джерел енергозбереження. Запропоновано можливі шляхи вирішення проблеми фінансування впровадження енергозберігаючих заходів або створення фонду енергоефективності.The correct taking into consideration the uncertainty of the initial information is an important element in the process of decision of a wide range of problems of operational control and planning in the modern distribution systems. The actuality of the mentioned problem will not disappear in the course of the further formation of the integrated power systems. Inevitable development of information base in a certain measure will be compensated by the additional uncertainty, brought by active implementation of alternative energy sources. In this connection, the approach, allowing one to use in the optimal form the all available in power company’s direct and indirect information related to electrical loads, is offered in this article. The developed algorithms allow forming the generalized estimates of loads and certain characteristics of energy sources of the distributed generation on the basis of aggregation of the diverse retrospective data. To realize this problem the mathematical approach of the fuzzy sets theory is used.Проведен анализ публикаций, касающихся потенциала энергоснабжения в Украине. Показаны проблемы финансирования бюджетной сферы на потребности теплообеспечения. Показана проблема нормирования затрат тепловой энергии. Дано описание несовершенства современных требований к сопротивлению теплопередаче ограждающих конструкций. Показаны требования к сопротивлению теплопередаче ограждающих конструкций некоторых иностранных государств. Показана необходимость применения статистически-математических методов для повышения уровня качества процесса анализа расходов на потребление тепловой энергии в зданиях бюджетной сферы Украины. Предложены методы определения источников энергосбережения. Предложены возможные пути решения проблемы финансирования внедрения мер по энергосбережению или создания фонда энергоэффективности
On a low energy bound in a class of chiral field theories with solitons
A low energy bound in a class of chiral solitonic field theories related the
infrared physics of the SU(N) Yang-Mills theory is established.Comment: Plain Latex, 8 pages, no figure
Observations of the SW Sextantis star DW Ursae Majoris with the Far Ultraviolet Spectroscopic Explorer
We present an analysis of the first far-ultraviolet observations of the SW
Sextantis-type cataclysmic variable DW Ursae Majoris, obtained in November 2001
with the Far Ultraviolet Spectroscopic Explorer. The time-averaged spectrum of
DW UMa shows a rich assortment of emission lines (plus some contamination from
interstellar absorption lines including molecular hydrogen). Accretion disk
model spectra do not provide an adequate fit to the far-ultraviolet spectrum of
DW UMa. We constructed a light curve by summing far-ultraviolet spectra
extracted in 60-sec bins; this shows a modulation on the orbital period, with a
maximum near photometric phase 0.93 and a minimum half an orbit later. No other
periodic variability was found in the light curve data. We also extracted
spectra in bins spanning 0.1 in orbital phase; these show substantial variation
in the profile shapes and velocity shifts of the emission lines during an
orbital cycle of DW UMa. Finally, we discuss possible physical models that can
qualitatively account for the observed far-ultraviolet behavior of DW UMa, in
the context of recent observational evidence for the presence of a
self-occulting disk in DW UMa and the possibility that the SW Sex stars may be
the intermediate polars with the highest mass transfer rates and/or weakest
magnetic fields.Comment: accepted by the Astronomical Journal; 36 pages, including 12 figures
and 4 table
The extensions of gravitational soliton solutions with real poles
We analyse vacuum gravitational "soliton" solutions with real poles in the
cosmological context. It is well known that these solutions contain
singularities on certain null hypersurfaces. Using a Kasner seed solution, we
demonstrate that these may contain thin sheets of null matter or may be simple
coordinate singularities, and we describe a number of possible extensions
through them.Comment: 14 pages, LaTeX, 6 figures included using graphicx; to appear in Gen.
Rel. Gra
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