2,282 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
On algebraic endomorphisms of the Einstein gyrogroup
We describe the structure of all continuous algebraic endomorphisms of the
open unit ball of equipped with the Einstein
velocity addition. We show that any nonzero such transformation originates from
an orthogonal linear transformation on
Metal-rich or misclassified? The case of four RR Lyrae stars
We analysed the light curve of four, apparently extremely metal-rich
fundamental-mode RR Lyrae stars. We identified two stars, MT Tel and ASAS
J091803-3022.6 as RRc (first-overtone) pulsators that were misclassified as
RRab ones in the ASAS survey. In the case of the other two stars, V397 Gem and
ASAS J075127-4136.3, we could not decide conclusively, as they are outliers in
the period-Fourier-coefficient space from the loci of both classes, but their
photometric metallicities also favour the RRc classification.Comment: 5 pages, 2 figures, published in IBVS:
http://ibvs.konkoly.hu/cgi-bin/IBVS?617
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
Constraining RRc candidates using SDSS colours
The light variations of first-overtone RR Lyrae stars and contact eclipsing
binaries can be difficult to distinguish. The Catalina Periodic Variable Star
catalog contains several misclassified objects, despite the classification
efforts by Drake et al. (2014). They used metallicity and surface gravity
derived from spectroscopic data (from the SDSS database) to rule out binaries.
Our aim is to further constrain the catalog using SDSS colours to estimate
physical parameters for stars that did not have spectroscopic data.Comment: 2 pages, 1 figure, proceedings of the RRL2015 - High-Precision
Studies of RR Lyrae Stars conference, to appear in the Communications from
the Konkoly Observator
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