59,782 research outputs found
Exact Quantum States for all Two-Dimensional Dilaton Gravity Theories
It is shown that the recently obtained quantum wave functionals in terms of
the CJZ variables for generic 2d dilaton gravity are equivalent to the
previously reported exact quantum wave functionals in geometrical variables. A
third representation of these exact quantum states is also presented
Black hole mass estimates in quasars - A comparative analysis of high- and low-ionization lines
The inter-line comparison between high- and low-ionization emission lines has
yielded a wealth of information on the quasar broad line region (BLR) structure
and dynamics, including perhaps the earliest unambiguous evidence in favor of a
disk + wind structure in radio-quiet quasars. We carried out an analysis of the
CIV 1549 and Hbeta line profiles of 28 Hamburg-ESO high luminosity quasars and
of 48 low-z, low luminosity sources in order to test whether the
high-ionization line CIV 1549 width could be correlated with Hbeta and be used
as a virial broadening estimator. We analyze intermediate- to high-S/N,
moderate resolution optical and NIR spectra covering the redshifted CIV and
H over a broad range of luminosity log L ~ 44 - 48.5 [erg/s] and
redshift (0 - 3), following an approach based on the quasar main sequence. The
present analysis indicates that the line width of CIV 1549 is not immediately
offering a virial broadening estimator equivalent to H. At the same time
a virialized part of the BLR appears to be preserved even at the highest
luminosities. We suggest a correction to FWHM(CIV) for Eddington ratio (using
the CIV blueshift as a proxy) and luminosity effects that can be applied over
more than four dex in luminosity. Great care should be used in estimating
high-L black hole masses from CIV 1549 line width. However, once corrected
FWHM(CIV) values are used, a CIV-based scaling law can yield unbiased MBH
values with respect to the ones based on H with sample standard
deviation ~ 0.3 dex.Comment: 43 pages, 15 Figures, submitted to A&
Modelling the exposure to Cronobacter sakazakii by consumption of a cocoa-milk-based beverage processed by pulsed electric fields
peer-reviewedM.C. Pina-Pérez is grateful to CSIC for providing a DOCTOR contract linked to the INNPACTO project IPT-2011-1724-060000. This study was carried out with funds from BISOSTAD project PSE-060000-2009-003, Generalitat Valenciana I+D+I emergent research groups GV/2010/064 and CYCIT project AGL2010-22206-C02-01.Infants’ exposure (Nf ) to Cronobacter sakazakii via the consumption of infant-rich-inpolyphenols
cocoa-milk-based beverages (CCX-M) treated with high-intensity pulsed
electric fields (PEF) was evaluated. Monte Carlo simulation enabled the prediction
of the variability in C. sakazakii load in beverages at the time of consumption to be
estimated. Different scenarios (initial contamination levels; PEF treatment conditions;
and time-temperature combinations of CCX-M beverages storage after treatment) were
simulated. Cocoa addition and PEF treatment resulted in the most influential input
factors to control bacterial final load. Cronobacter spp. exposure risk was reduced by
a maximum of 100 times at 95% of iterations due to addition of cocoa at 5 g/100 mL,
corresponding to scenario 3 (PEF: 15 kV/cm–3,000 μs; storage 120 h at 8 °C). Moreover,
the probability of illness for a healthy population was reduced from 2.15 × 10-8,
in the baseline scenario, to 4.78 × 10-10 due to cocoa addition and application of
15 kV/cm–3,000 μs PEF treatment.BISOSTAD projec
The next-to-leading order vertex for a forward jet plus a rapidity gap at high energies
We present the results for the calculation of the forward jet vertex
associated to a rapidity gap (coupling of a hard pomeron to the jet) in the
Balitsky-Fadin-Kuraev-Lipatov (BFKL) formalism at next-to-leading order (NLO).
We handle the real emission contributions making use of the high energy
effective action proposed by Lipatov, valid for multi-Regge and
quasi-multi-Regge kinematics. This result is important since it allows,
together with the NLO non-forward gluon Green function, to perform NLO studies
of jet production in diffractive events (Mueller-Tang dijets, as a well-known
example).Comment: 12 pages, some figure
The luminosity function of Palomar 5 and its tidal tails
We present the main sequence luminosity function of the tidally disrupted
globular cluster Palomar 5 and its tidal tails. For this work we analyzed
imaging data obtained with the Wide Field Camera at the INT (La Palma) and data
from the Wide Field Imager at the MPG/ESO 2.2 m telescope at La Silla down to a
limiting magnitude of approximately 24.5 mag in B. Our results indicate that
preferentially fainter stars were removed from the cluster so that the LF of
the cluster's main body exhibits a significant degree of flattening compared to
other GCs. This is attributed to its advanced dynamical evolution. The LF of
the tails is, in turn, enhanced with faint, low-mass stars, which we interpret
as a consequence of mass segregation in the cluster.Comment: 4 pages, 3 figures, to be published in the proceedings of the
conference "Satellites and tidal streams" held at La Palma, Canary Islands,
May 26 - 30, 200
Three body systems with strangeness and exotic systems
We report on four 's and three 's, in the 1500 - 1800 MeV
region, as two meson - one baryon S-wave resonances found by solving
the Faddeev equations in the coupled channel approach, which can be associated
to the existing = -1, low lying baryon resonances. On the
other hand we also report on a new, hidden strangeness state, mostly made
of , with mass around 1920 MeV, which we think could be
responsible for the peak seen in the around this
energy. Finally we address a very novel topic in which we show how few body
systems of several mesons can be produced, with their spins aligned up
to J=6, and how these states found theoretically can be associated to several
known mesons with spins J=2,3,4,5,6.Comment: Talk at the 21st European Conference on Few Body Problems in Physics,
Salamanca, Sep. 201
Defining perturbations on submanifolds
We study the definition of perturbations in the presence of a submanifold, like e.g. a brane. In the standard theory of cosmological perturbations, one compares quantities at the same coordinate points in the non-perturbed and the perturbed manifolds, identified via a (non-unique) mapping between the two manifolds. In the presence of a physical submanifold one needs to modify this definition in order to evaluate perturbations of quantities at the submanifold location. As an application, we compute the perturbed metric and the extrinsic curvature tensors at the brane position in a general gauge
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