3,742 research outputs found
Neutrino oscillations in low density medium
For the case of small matter effects: , where is the
matter potential, we develop the perturbation theory using as the expansion parameter. We derive simple and physically
transparent formulas for the oscillation probabilities in the lowest order in
which are valid for arbitrary density profile. The formulas can be
applied for propagation of the solar and supernova neutrinos in matter of the
Earth, substantially simplifying numerical calculations. Using these formulas
we study sensitivity of the oscillation effects to structures of the density
profile situated at different distances from the detector . We show that for
the mass-to-flavor state transitions, {\it e.g.}, , the
sensitivity is suppressed for remote structures: ,
where is the oscillation length and is the energy
resolution of detector.Comment: discussion simplified, clarifications adde
Lithium Experiment on Solar Neutrinos to Weight the CNO Cycle
The measurement of the flux of beryllium neutrinos with the accuracy of about
10% and CNO neutrinos with the accuracy 30% will enable to find the flux of
pp-neutrinos in the source with the accuracy better than 1% using the
luminosity constraint. The future experiments on \nu e- scattering will enable
to measure with very good accuracy the flux of beryllium and pp-neutrinos on
the Earth. The ratio of the flux of pp-neutrinos on the Earth and in the source
will enable to find with very good accuracy a mixing angle theta solar. Lithium
detector has high sensitivity to CNO neutrinos and can find the contribution of
CNO cycle to the energy generated in the Sun. This will be a stringent test of
the theory of stellar evolution and combined with other experiments will
provide a precise determination of the flux of pp-neutrinos in the source and a
mixing angle theta solar. The work on the development of the technology of
lithium experiment is now in progress.Comment: Minor corrections, one reference added, 11 pages, 2 figures, talk
given at NANP 2003, Dubna, Russia, June 200
The views and practice of oncologists towards nutritional support in patients receiving chemotherapy
Malnutrition in patients with cancer is common and an adverse prognostic indicator. A questionnaire answered by 357 (72%) UK specialist oncological trainees suggests that they lack the ability to identify factors that place patients at risk from malnutrition. Major barriers to effective nutritional practice included lack of guidelines, knowledge and time
First Scientific Results From The Infrared Astronomical Satellite (IRAS)
The Infrared Astronomical Satellite (IRAS) was successfully launched on 25 January 1983 and terminated science data acquisition on 22 November 1983. The in-orbit performance of the telescope has been described in two previous papers in these proceedings. A previous description of very preliminary scientific results from the mission has been given in these proceedings, while far more extensive reports have been given elsewhere. In this paper we will summarize some of the results obtained to date from the IRAS data. The work to date has sampled only a small fraction of the IRAS data; the study of the data from the IRAS survey will continue for many years to come
Super-Poincare' algebras, space-times and supergravities (I)
A new formulation of theories of supergravity as theories satisfying a
generalized Principle of General Covariance is given. It is a generalization of
the superspace formulation of simple 4D-supergravity of Wess and Zumino and it
is designed to obtain geometric descriptions for the supergravities that
correspond to the super Poincare' algebras of Alekseevsky and Cortes'
classification.Comment: 29 pages, v2: minor improvements at the end of Section 5.
Regularity of Kobayashi metric
We review some recent results on existence and regularity of Monge-Amp\`ere
exhaustions on the smoothly bounded strongly pseudoconvex domains, which admit
at least one such exhaustion of sufficiently high regularity. A main
consequence of our results is the fact that the Kobayashi pseudo-metric k on an
appropriare open subset of each of the above domains is actually a smooth
Finsler metric. The class of domains to which our result apply is very large.
It includes for instance all smoothly bounded strongly pseudoconvex complete
circular domains and all their sufficiently small deformations.Comment: 14 pages, 8 figures - The previously announced main result had a gap.
In this new version the corrected statement is given. To appear on the volume
"Geometric Complex Analysis - Proceedings of KSCV 12 Symposium
Clinical features, anaesthetic management and perioperative complications seen in three horses with pheochromocytoma
Three horses presenting with colic signs to the Equine Referral Hospital at The Royal Veterinary College underwent general anaesthesia between September 2013 and November 2017 for emergency exploratory laparotomy. No obvious cause for the colic signs was identified in two horses, while a haemoperitoneum was identified in the third. All horses were euthanased within 12 hours of surgery due to deteriorating haemodynamic instability and/or intractable pain. Postmortem examination revealed an adrenal mass in each case, confirmed to be a pheochromocytoma on histopathology. In retrospect, each horse had some hallmark characteristics consistent with a functional pheochromocytoma, including hyperglycaemia and hyperlactataemia. Extremely high packed cell volume (PCV) (>65 per cent) was also identified in two horses, with a high-normal PCV found in the haemoperitoneum case. Perioperative haemodynamic instability was predominantly characterised by episodes of intermittent hypertension and tachycardia
On Spacetimes with Constant Scalar Invariants
We study Lorentzian spacetimes for which all scalar invariants constructed
from the Riemann tensor and its covariant derivatives are constant (
spacetimes). We obtain a number of general results in arbitrary dimensions. We
study and construct warped product spacetimes and higher-dimensional
Kundt spacetimes. We show how these spacetimes can be constructed from
locally homogeneous spaces and spacetimes. The results suggest a number
of conjectures. In particular, it is plausible that for spacetimes that
are not locally homogeneous the Weyl type is , , or , with any
boost weight zero components being constant. We then consider the
four-dimensional spacetimes in more detail. We show that there are severe
constraints on these spacetimes, and we argue that it is plausible that they
are either locally homogeneous or that the spacetime necessarily belongs to the
Kundt class of spacetimes, all of which are constructed. The
four-dimensional results lend support to the conjectures in higher dimensions.Comment: 25 pages, 1 figure, v2: minor changes throughou
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