Dark energy and Josephson junctions

It has been recently claimed that dark energy can be (and has been) observed in laboratory experiments by measuring the power spectrum $S_I(\omega)$ of the noise current in a resistively shunted Josephson junction and that in new dedicated experiments, which will soon test a higher frequency range, $S_I(\omega)$ should show a deviation from the linear rising observed in the lower frequency region because higher frequencies should not contribute to dark energy. Based on previous work on theoretical aspects of the fluctuation-dissipation theorem, we carefully investigate these issues and show that these claims are based on a misunderstanding of the physical origin of the spectral function $S_I(\omega)$. According to our analysis, dark energy has never been (and will never be) observed in Josephson junctions experiments. We also predict that no deviation from the linear rising behavior of $S_I(\omega)$ will be observed in forthcoming experiments. Our findings provide new (we believe definite) arguments which strongly support previous criticisms.Comment: 9 pages, no figure

Constraint Reasoning and Kernel Clustering for Pattern Decomposition with Scaling

Abstract. Motivated by an important and challenging task encountered in material discovery, we consider the problem of finding K basis patterns of numbers that jointly compose N observed patterns while enforcing additional spatial and scaling constraints. We propose a Constraint Pro-gramming (CP) model which captures the exact problem structure yet fails to scale in the presence of noisy data about the patterns. We allevi-ate this issue by employing Machine Learning (ML) techniques, namely kernel methods and clustering, to decompose the problem into smaller ones based on a global data-driven view, and then stitch the partial solu-tions together using a global CP model. Combining the complementary strengths of CP and ML techniques yields a more accurate and scalable method than the few found in the literature for this complex problem.

Scaling critical behavior of superconductors at zero magnetic field

We consider the scaling behavior in the critical domain of superconductors at zero external magnetic field. The first part of the paper is concerned with the Ginzburg-Landau model in the zero magnetic field Meissner phase. We discuss the scaling behavior of the superfluid density and we give an alternative proof of Josephson's relation for a charged superfluid. This proof is obtained as a consequence of an exact renormalization group equation for the photon mass. We obtain Josephson's relation directly in the form $\rho_{s}\sim t^{\nu}$, that is, we do not need to assume that the hyperscaling relation holds. Next, we give an interpretation of a recent experiment performed in thin films of $YBa_{2}Cu_{3}O_{7-\delta}$. We argue that the measured mean field like behavior of the penetration depth exponent $\nu'$ is possibly associated with a non-trivial critical behavior and we predict the exponents $\nu=1$ and $\alpha=-1$ for the correlation lenght and specific heat, respectively. In the second part of the paper we discuss the scaling behavior in the continuum dual Ginzburg-Landau model. After reviewing lattice duality in the Ginzburg-Landau model, we discuss the continuum dual version by considering a family of scalings characterized by a parameter $\zeta$ introduced such that $m_{h,0}^2\sim t^{\zeta}$, where $m_{h,0}$ is the bare mass of the magnetic induction field. We discuss the difficulties in identifying the renormalized magnetic induction mass with the photon mass. We show that the only way to have a critical regime with $\nu'=\nu\approx 2/3$ is having $\zeta\approx 4/3$, that is, with $m_{h,0}$ having the scaling behavior of the renormalized photon mass.Comment: RevTex, 15 pages, no figures; the subsection III-C has been removed due to a mistak

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Measurement of colour flow with the jet pull angle in View the MathML sourcett¯ events using the ATLAS detector at View the MathML sources=8 TeV

The distribution and orientation of energy inside jets is predicted to be an experimental handle on colour connections between the hard-scatter quarks and gluons initiating the jets. This Letter presents a measurement of the distribution of one such variable, the jet pull angle. The pull angle is measured for jets produced in View the MathML sourcett¯ events with one W boson decaying leptonically and the other decaying to jets using 20.3 fb−1 of data recorded with the ATLAS detector at a centre-of-mass energy of View the MathML sources=8 TeV at the LHC. The jet pull angle distribution is corrected for detector resolution and acceptance effects and is compared to various models

Nanocrystalline W-doped SrBi 2Ta 2O 9 of layered perovskite structure derived from mechanical activation

Journal of Metastable and Nanocrystalline Materials2359-6

Ferroelectric Bi4-xSmxTi3O12 thin films fabricated by pulsed laser deposition for Nv-RAM applications

10.1080/10584580490459026Integrated Ferroelectrics61123-127IFER

Surface modification of magnetron-sputtered hydroxyapatite thin films via silicon substitution for orthopaedic and dental applications

10.1016/j.surfcoat.2010.12.012Surface and Coatings Technology205113472-347

Ferroelectric behaviors of W-doped SrBi 2Ta 2O 9 thin films

10.1080/10584580490456515Integrated Ferroelectrics62163-169IFER