Comment on "Separability of quantum states and the violation of Bell-type inequalities"

The statement of E.R. Loubenets, Phys. Rev. A 69, 042102 (2004), that separable states can violate classical probabilistic constraints is based on a misleading definition of classicality, which is much narrower than Bell's concept of local hidden variables. In a Bell type setting the notion of classicality used by Loubenets corresponds to the assumption of perfect correlations if the same observable is measured on both sides. While it is obvious that most separable states do not satisfy this assumption, this does not constitute "non-classical" behaviour in any usual sense of the word.Comment: 1 page, accepted by Phys. Rev.

A stellar census of the nearby, young 32 Orionis group

The 32 Orionis group was discovered almost a decade ago and despite the fact that it represents the first northern, young (age ~ 25 Myr) stellar aggregate within 100 pc of the Sun ($d \simeq 93$ pc), a comprehensive survey for members and detailed characterisation of the group has yet to be performed. We present the first large-scale spectroscopic survey for new (predominantly M-type) members of the group after combining kinematic and photometric data to select candidates with Galactic space motion and positions in colour-magnitude space consistent with membership. We identify 30 new members, increasing the number of known 32 Ori group members by a factor of three and bringing the total number of identified members to 46, spanning spectral types B5 to L1. We also identify the lithium depletion boundary (LDB) of the group, i.e. the luminosity at which lithium remains unburnt in a coeval population. We estimate the age of the 32 Ori group independently using both isochronal fitting and LDB analyses and find it is essentially coeval with the {\beta} Pictoris moving group, with an age of $24\pm4$ Myr. Finally, we have also searched for circumstellar disc hosts utilising the AllWISE catalogue. Although we find no evidence for warm, dusty discs, we identify several stars with excess emission in the WISE W4-band at 22 {\mu}m. Based on the limited number of W4 detections we estimate a debris disc fraction of $32^{+12}_{-8}$ per cent for the 32 Ori group.Comment: Accepted for publication in MNRAS; 24 pages, 17 figures and 10 table

Proposal to demonstrate the non-locality of Bohmian mechanics with entangled photons

Bohmian mechanics reproduces all statistical predictions of quantum mechanics, which ensures that entanglement cannot be used for superluminal signaling. However, individual Bohmian particles can experience superluminal influences. We propose to illustrate this point using a double double-slit setup with path-entangled photons. The Bohmian velocity field for one of the photons can be measured using a recently demonstrated weak-measurement technique. The found velocities strongly depend on the value of a phase shift that is applied to the other photon, potentially at spacelike separation.Comment: 6 pages, 4 figure

Esmase skisofreenia farmakoteraapia Eestis: võrdlus kohaliku ja rahvusvaheliste ravijuhistega

Psühhooside farmakoteraapia ja ravijuhised on eri riikides erinevad. Uuringu eesmärgiks oli analüüsida ja kirjeldada esmaste skisofreeniaepisoodide farmakoteraapiat Eestis. Töös analüü- siti septembrist 2005 kuni septembrini 2006 Põhja-Eesti Regionaalhaigla ja TÜ Kliinikumi psühhiaatriakliinikutesse hospitaliseeritud skisofreenia ja skisotüüpse häirega patsientide farmakoteraapiat. Vaadeldi manustatud ravimite annuseid, antipsühhootikumide polüteraapia esinemise sagedust ning atüüpiliste ja konventsionaalsete antipsühhootikumide määramise sagedust. Tulemusi võrreldi kohalike ja rahvusvaheliste ravijuhistega. Esmase skisofreenia farmakoteraapia Eestis on suures osas vastavuses Eesti ja rahvusvaheliste ravijuhistega, kuid sageli kasutati konventsionaalseid antipsühhootikume ja levinud oli polüteraapia antipsühhootikumidega. Tõenduspõhise farmakoteraapia soodustamiseks oleks otstarbekas ajakohastada Eesti ravijuhiseid. Eesti Arst 2008; 87(9):601−60

Toroidal Perturbations of Friedmann-Robertson-Walker Universes

Explicit expressions are found for the axisymmetric metric perturbations of the closed, flat and open FRW universes caused by toroidal motions of the cosmic fluid. The perturbations are decomposed in vector spherical harmonics on 2-spheres, but the radial dependence is left general. Solutions for general odd-parity $l$-pole perturbations are given for either angular velocities or angular momenta prescribed. In particular, in case of closed universes the solutions require a special treatment of the Legendre equation.Comment: 13 page

Realisation of Hardy's Thought Experiment

We present an experimental realisation of Hardy's thought experiment [Phys. Rev. Lett. {\bf 68}, 2981 (1992)], using photons. The experiment consists of a pair of Mach-Zehnder interferometers that interact through photon bunching at a beam splitter. A striking contradiction is created between the predictions of quantum mechanics and local hidden variable based theories. The contradiction relies on non-maximally entangled position states of two particles.Comment: 5 page

Experimental test of nonlocal realistic theories without the rotational symmetry assumption

We analyze the class of nonlocal realistic theories that was originally considered by Leggett [Found. Phys. 33, 1469 (2003)] and tested by us in a recent experiment [Nature (London) 446, 871 (2007)]. We derive an incompatibility theorem that works for finite numbers of polarizer settings and that does not require the previously assumed rotational symmetry of the two-particle correlation functions. The experimentally measured case involves seven different measurement settings. Using polarization-entangled photon pairs, we exclude this broader class of nonlocal realistic models by experimentally violating a new Leggett-type inequality by 80 standard deviations.Comment: Published versio

Hidden-variable theorems for real experiments

It has recently been questioned whether the Kochen-Specker theorem is relevant to real experiments, which by necessity only have finite precision. We give an affirmative answer to this question by showing how to derive hidden-variable theorems that apply to real experiments, so that non-contextual hidden variables can indeed be experimentally disproved. The essential point is that for the derivation of hidden-variable theorems one does not have to know which observables are really measured by the apparatus. Predictions can be derived for observables that are defined in an entirely operational way.Comment: 4 page

An Exploratory Examination of Burnout in NCAA Division II Athletes

The purpose of this study was to assess the causes of burnout among student-athletes in Division II institutions. The authors distributed the Athlete Burnout Questionnaire (ABQ) to 125 undergraduate student-athletes enrolled at three Division II colleges and universities. The athletes competed in various sports. A 2 (Gender) × 2 (Type of Scholarship) × 2 (School Status) analysis of variance revealed that women and men reported different levels of burnout dependent upon type of scholarship. Men with no scholarship reported the lowest levels of burnout among the three types (None/Academic/Athletic), whereas women with no type of scholarship reported the highest levels of burnout. The authors discuss the results and offer implications, limitations, and future directions