Neutrino Spectral Split in the Exact Many Body Formalism

We consider the many-body system of neutrinos interacting with each other through neutral current weak force. Emerging many-body effects in such a system could play important roles in some astrophysical sites such as the core collapse supernovae. In the literature this many-body system is usually treated within the mean field approximation which is an effective one-body description based on omitting entangled neutrino states. In this paper, we consider the original many-body system in an effective two flavor mixing scenario under the single angle approximation and present a solution without using the mean field approximation. Our solution is formulated around a special class of many-body eigenstates which do not undergo any level crossings as the neutrino self interaction rate decreases while the neutrinos radiate from the supernova. In particular, an initial state which consists of electron neutrinos and antineutrinos of an orthogonal flavor can be entirely decomposed in terms of those eigenstates. Assuming that the conditions are perfectly adiabatic so that the evolution of these eigenstates follow their variation with the interaction rate, we show that this initial state develops a spectral split at exactly the same energy predicted by the mean field formulation.Comment: Published version. 30 pages, 11 figure

Low velocity quantum reflection of Bose-Einstein condensates

We studied quantum reflection of Bose-Einstein condensates at normal incidence on a square array of silicon pillars. For incident velocities of 2.5-26 mm/s observations agreed with theoretical predictions that the Casimir-Polder potential of a reduced density surface would reflect slow atoms with much higher probability. At low velocities (0.5-2.5 mm/s), we observed that the reflection probability saturated around 60% rather than increasing towards unity. We present a simple model which explains this reduced reflectivity as resulting from the combined effects of the Casimir-Polder plus mean field potential and predicts the observed saturation. Furthermore, at low incident velocities, the reflected condensates show collective excitations.Comment: 4 figure

Direct observation of optically induced transient structures in graphite using ultrafast electron crystallography

We use ultrafast electron crystallography to study structural changes induced in graphite by a femtosecond laser pulse. At moderate fluences of ~< 21mJ/cm^2, lattice vibrations are observed to thermalize on a time scale of ~8ps. At higher fluences approaching the damage threshold, lattice vibration amplitudes saturate. Following a marked initial contraction, graphite is driven nonthermally into a transient state with sp^3-like character, forming interlayer bonds. Using ab initio density functional calculations, we trace the governing mechanism back to electronic structure changes following the photo-excitation.Comment: 5 pages, 4 figures; to appear in Phys. Rev. Let

Epicardial fat thickness in patients with rheumatoid arthritis

Background: Epidemiologic data indicates that rheumatoid arthritis is an independent risk factor for cardiovascular disease. Epicardial adipose tissue is a novel cardio-metabolic risk factor. Our aim was to evaluate epicardial fat thickness (EFT) using echocardiography in patients with rheumatoid arthritis compared to healthy control subjects. Secondly, we investigated relationship between epicardial fat thickness and clinical and echocardiographic parameters in patients with rheumatoid arthritis.Method: The study population included 76 consecutive patients with rheumatoid arthritis (64 female; mean age, 53 ±11 years, median disease duration, 7.8 years) and 50 healthy subjects as controls (39 female; mean age, 52 ± 6 years). All patients underwent echocardiography to assess left ventricular diastolic dysfunction, left ventricular hypertrophy and EFT. All values were compared between groups.Results: EFT was higher in rheumatoid arthritis patients than in healthy controls (0.66±0.20 vs. 0.54±0.18; p= 0.003). Thickness of Intra Ventricular Septum (IVS) (1.1±0.06 and 9.8±0.08; p=0.001) and posterior wall (PW) (0.98±0.05 and 0.93±0.08; p=0.015) was higher in patients with rheumatoid arthritis compared to healthy controls. Early diastolic myocardiac peak velocity or late diastolic mitral peak velocity (E/A) ratio was lower in rheumatoid arthritis patients compared to healthy patients (1.1 ±0.8 and 1.24±0.1 p=0.001) as well as, E/e’ was higher in Rheumatoid arthritis (RA) patients than healthy patients. (E/e’:8.7±1.6 and 8.0±1.4 p=0.020). In patients with rheumatoid arthritis, EFT was positively correlated with hypertension and duration of disease and E/e’ (r: 0.10, p: 0.010, r: 0.306, p: 0.004 and r: 0.465 p: 0.007 respectively) and EFT was negatively correlated with E/A (r: -.262 p:0.022 )Conclusion: To our knowledge, this is the first report about epicardial adipose tissue in rheumatoid arthritis patients. Epicardial fat thickness as an indicator of cardiovascular involvement was higher in rheumatoid arthritis patients.Keywords: Rheumatoid arthritis, epicardial fat thickness, cardiac involvemen

Hair glucocorticoids in adults with intellectual disabilities and depressive symptoms pre- and post-bright light therapy:First explorations

BACKGROUND: Depressive symptoms and stress are common in adults with intellectual disabilities. Our aim was to explore long‐term biological stress levels, assessed by hair cortisol (HairF) and cortisone (HairE) concentrations, in adults with intellectual disabilities and depressive symptoms and to investigate the effects of bright light therapy (BLT) on hair glucocorticoids. METHOD: Scalp hair samples (n = 14) were retrospectively examined at baseline and post‐BLT (10.000 and 300 lux). Liquid chromatography–tandem mass spectrometry was used to measure hair glucocorticoids. RESULTS: A significant correlation was found between baseline HairF and depression scores (r = .605, p = .028). Post‐intervention HairE levels were significantly increased ([95% CI: 11.2–17.4 pg/mg], p = .003), in particular after dim light (300 lux) ([95% CI: 10.0–18.3 pg/mg], p = .020). CONCLUSIONS: This study showed that retrospectively examining biological levels of stress in adults with intellectual disabilities seems a potentially promising and objective method to gain insight in the stress level of adults with intellectual disabilities

Phenomenology, Astrophysics and Cosmology of Theories with Sub-Millimeter Dimensions and TeV Scale Quantum Gravity

We recently proposed a solution to the hierarchy problem not relying on low-energy supersymmetry or technicolor. Instead, the problem is nullified by bringing quantum gravity down to the TeV scale. This is accomplished by the presence of $n \geq 2$ new dimensions of sub-millimeter size, with the SM fields localised on a 3-brane in the higher dimensional space. In this paper we systematically study the experimental viability of this scenario. Constraints arise both from strong quantum gravitational effects at the TeV scale, and more importantly from the production of massless higher dimensional gravitons with TeV suppressed couplings. Theories with $n>2$ are safe due mainly to the infrared softness of higher dimensional gravity. For $n=2$, the six dimensional Planck scale must be pushed above $\sim 30$ TeV to avoid cooling SN1987A and distortions of the diffuse photon background. Nevertheless, the particular implementation of our framework within type I string theory can evade all constraints, for any $n \geq 2$, with string scale $m_s \sim 1$ TeV. We also explore novel phenomena resulting from the existence of new states propagating in the higher dimensional space. The Peccei-Quinn solution to the strong CP problem is revived with a weak scale axion in the bulk. Gauge fields in the bulk can mediate repulsive forces $\sim 10^6 - 10^8$ times stronger than gravity at sub-mm distances, and may help stabilize the proton. Higher-dimensional gravitons produced on our brane and captured on a different "fat" brane can provide a natural dark matter candidate.Comment: 51 pages, late

Hybrid networks: Improving deep learning networks via integrating two views of images

© 2018, Springer Nature Switzerland AG. The principal component analysis network (PCANet) is an unsupervised parsimonious deep network, utilizing principal components as filters in the layers. It creates an amalgamated view of the data by transforming it into column vectors which destroys its spatial structure while obtaining the principal components. In this research, we first propose a tensor-factorization based method referred as the Tensor Factorization Networks (TFNet). The TFNet retains the spatial structure of the data by preserving its individual modes. This presentation provides a minutiae view of the data while extracting matrix factors. However, the above methods are restricted to extract a single representation and thus incurs information loss. To alleviate this information loss with the above methods we propose Hybrid Network (HybridNet) to simultaneously learn filters from both the views of the data. Comprehensive results on multiple benchmark datasets validate the superiority of integrating both the views of the data in our proposed HybridNet