Bell inequalities for random fields

The assumptions required for the derivation of Bell inequalities are not usually satisfied for random fields in which there are any thermal or quantum fluctuations, in contrast to the general satisfaction of the assumptions for classical two point particle models. Classical random field models that explicitly include the effects of quantum fluctuations on measurement are possible for experiments that violate Bell inequalities.Comment: 18 pages; 1 figure; v4: Essentially the published version; extensive improvements. v3: Better description of the relationship between classical random fields and quantum fields; better description of random field models. More extensive references. v2: Abstract and introduction clarifie

Sub-continental transport mechanisms and pathways during two ozone episodes in northern Spain

International audienceTwo ozone episodes (occurring in June 2001 and June 2003) in the air quality monitoring network of the Basque Country (BC) are analyzed. The population information threshold was exceeded in many stations (urban, urban-background and rural). During this type of episodes, forced by a blocking anticyclone over the British Isles, ozone background concentrations over the area increase after the import of pollution from both, the continental Europe and the western Mediterranean areas (Gangoiti et al., 2002). For the present analysis, emphasis is made in the search for transport mechanisms, pathways and area sources contributing to the build-up of the episodes. Contributions from a selection of 17 urban and industrial conglomerates in the western European Atlantic (WEA) and the western Mediterranean (WM) are shown after the results of a coupled RAMS-HYPACT modelling system. Meteorological simulations are tested against both the high-resolution wind data recorded at the BC coastal area by a boundary layer wind-profiler radar (Alonso et al., 1998) and the wind soundings reported by the National Centres of Meteorology at a selection of European and north-African sites. Results show that during the accumulation phase of the episodes, background ozone concentrations increase in the whole territory as a consequence of transport from the Atlantic coast of France and the British Channel. For the peak phase, intrusions from new sources, located at the Western Mediterranean, Southern France, Ebro Valley, and, occasionally, the area of Madrid are added, resulting in a further increase in the ozone concentrations. Direct day and night transport within the north-easterly winds over the sea from the WEA source region, and night-time transport within the residual layer over continental areas (southern France, the Ebro Valley, and central Iberia) modulate the import sequence of pollutants and the local increase of ozone concentrations. The alternative direct use of low resolution meteorological data for the estimation of back-trajectories shows a more simple transport scheme with no contributions neither from the Western Mediterranean nor from the Madrid area

The torsional Raman spectra of C2H6 and C2D6

8 pags., 2 figs., 5 tabs.The torsional Raman spectra of C2H6 and C 2D6 have been experimentally investigated with an improved conventional Raman spectrometer. Wave numbers and absolute cross sections of all observed bands have been satisfactorily interpreted within the experimental accuracy by means of a simple, pure-torsional Hamiltonian and a model for the torsional dependence of the molecular polarizability. The effective threefold potential barrier parameters for C2H6 have been taken from the recent literature, whilst for C2D6 the values V 3eff (C2D6) = 990 ± 2 cm-1 and V6eff (C2D6) = 7.9 ± 1 cm -1 were obtained. © 1989 American Institute of Physics.One of us (J.M.) thanks Ministerio de Educacion y Ciencia of Spain for a grant of the FPI Program. Thanks are due to the ~tiftung Volkswagenwerk of the Federal Republic of Germany for providing the high power laser source used in the present work.Peer reviewe

Torsional transitions in the conventional raman spectrum of ethanes

6 pags., 1 fig., 1 tab.A conventional Jarrell-Ash 25-100 double monochromator has been improved for high sensitivity Raman spectroscopy. The improvements include 2360 1/mm holographic gratings, a special RCA C31034A photomultiplier detector and sample cells especially designed by us for low level of stray light. With this apparatus the very weak torsional gas phase Raman spectra of ethanes C2H6, C2D6 and CH3CD3 has been recorded. Careful monitoring of all experimental variables combined with an efficient data acquisition and processing system enables a signal/noise ratio similar to that obtained with an intracavity set-up. For C2D6 this is the first time the torsional spectrum is reported. Wavenumbers and relative intensities for these transitions are given. © 1988.One of us (JMF) thanks Ministerio de Education y Ciencia of Spain for a grant of the FPI Program.Peer reviewe

Assumptions Underlying Bell's Inequalities

There are several versions of Bell's inequalities, proved in different contexts, using different sets of assumptions. The discussions of their experimental violation often disregard some required assumptions and use loose formulations of others. The issue, to judge from recent publications, continues to cause misunderstandings. We present a very simple but general proof of Bell's inequalities, identifying explicitly the complete set of assumptions required.Comment: 14 pages. This preprint includes an appendix and some comments not included in the journal version (mainly in section 6), due to length limitations. Comments are welcome