Coherence vortices in one spatial dimension

Coherence vortices are screw-type topological defects in the phase of Glauber's two-point degree of quantum coherence, associated with pairs of spatial points at which an ensemble-averaged stochastic quantum field is uncorrelated. Coherence vortices may be present in systems whose dimensionality is too low to support spatial vortices. We exhibit lattices of such quantum-coherence phase defects for a one-dimensional model quantum system. We discuss the physical meaning of coherence vortices and propose how they may be realized experimentally.Comment: 5 pages, 3 figure

Dipolar condensates confined in a toroidal trap: ground state and vortices

We study a Bose-Einstein condensate of 52Cr atoms confined in a toroidal trap with a variable strength of s-wave contact interactions. We analyze the effects of the anisotropic nature of the dipolar interaction by considering the magnetization axis to be perpendicular to the trap symmetry axis. In the absence of a central repulsive barrier, when the trap is purely harmonic, the effect of reducing the scattering length is a tuning of the geometry of the system: from a pancake-shaped condensate when it is large, to a cigar-shaped condensate for small scattering lengths. For a condensate in a toroidal trap, the interaction in combination with the central repulsive Gaussian barrier produces an azimuthal dependence of the particle density for a fixed radial distance. We find that along the magnetization direction the density decreases as the scattering length is reduced but presents two symmetric density peaks in the perpendicular axis. For even lower values of the scattering length we observe that the system undergoes a dipolar-induced symmetry breaking phenomenon. The whole density becomes concentrated in one of the peaks, resembling an origin-displaced cigar-shaped condensate. In this context we also analyze stationary vortex states and their associated velocity field, finding that this latter also shows a strong azimuthal dependence for small scattering lengths. The expectation value of the angular momentum along the z direction provides a qualitative measure of the difference between the velocity in the different density peaks.Comment: 9 pages, 12 figure

Fluctuations of the vortex line density in turbulent flows of quantum fluids

We present an analytical study of fluctuations of the Vortex Line Density (VLD) $$ in turbulent flows of quantum fluids. Two cases are considered. The first one is the counterflowing (Vinen) turbulence, where the vortex lines are disordered, and the evolution of quantity $\mathcal{L}(t)$ obeys the Vinen equation. The second case is the quasi-classic turbulence, where vortex lines are believed to form the so called vortex bundles, and their dynamics is described by the HVBK equations. The latter case, is of a special interest, since a number of recent experiments demonstrate the $\omega ^{-5/3}$ dependence for spectrum VLD, instead of $\omega ^{1/3}$ law, typical for spectrum of vorticity. In nonstationary situation, in particular, in the fluctuating turbulent flow there is a retardation between the instantaneous value of the normal velocity and the quantity $\mathcal{L}$. This retardation tends to decrease in the accordance with the inner dynamics, which has a relaxation character. In both cases the relaxation dynamics of VLD is related to fluctuations of the relative velocity, however if for the Vinen case the rate of temporal change for $\mathcal{L}(t)$ is directly depends on $\delta \mathbf{v}_{ns}$, for the HVBK dynamics it depends on $\nabla \times \delta \mathbf{v}_{ns}$. As a result, for the disordered case the spectrum $<\delta \mathcal{L}(\omega) \delta \mathcal{L}(-\omega)>$ coincides with the spectrum $\omega ^{-5/3}$. In the case of the bundle arrangement, the spectrum of the VLD varies (at different temperatures) from $\omega ^{1/3}$ to $\omega ^{-5/3}$ dependencies. This conclusion may serve as a basis for the experimental determination of what kind of the turbulence is implemented in different types of generation.Comment: 8 pages, 29 reference

Superscaling Predictions for Neutral Current Quasielastic Neutrino-Nucleus Scattering

The application of superscaling ideas to predict neutral-current (NC) quasielastic (QE) neutrino cross sections is investigated. Results obtained within the relativistic impulse approximation (RIA) using the same relativistic mean field potential (RMF) for both initial and final nucleons -- a model that reproduces the experimental (e,e') scaling function -- are used to illustrate the ideas involved. While NC reactions are not so well suited for scaling analyses, to a large extent the RIA-RMF predictions do exhibit superscaling. Independence of the scaled response on the nuclear species is very well fulfilled. The RIA-RMF NC superscaling function is in good agreement with the experimental (e,e') one. The idea that electroweak processes can be described with a universal scaling function, provided that mild restrictions on the kinematics are assumed, is shown to be valid.Comment: 4 pages, 4 figures, published in PR

The SERENDIP 2 SETI project: Current status

Over the past 30 years, interest in extraterrestrial intelligence has progressed from philosophical discussion to rigorous scientific endeavors attempting to make contact. Since it is impossible to assess the probability of success and the amount of telescope time needed for detection, Search for Extraterrestrial Intelligence (SETI) Projects are plagued with the problem of attaining the large amounts of time needed on the world's precious few large radio telescopes. To circumvent this problem, the Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations (SERENDIP) instrument operates autonomously in a piggyback mode utilizing whatever observing plan is chosen by the primary observer. In this way, large quantities of high-quality data can be collected in a cost-effective and unobtrusive manner. During normal operations, SERENDIP logs statistically significant events for further offline analysis. Due to the large number of terrestrial and near-space transmitters on earth, a major element of the SERENDIP project involves identifying and rejecting spurious signals from these sources. Another major element of the SERENDIP Project (as well as most other SETI efforts) is detecting extraterrestrial intelligence (ETI) signals. Events selected as candidate ETI signals are studied further in a targeted search program which utilizes between 24 to 48 hours of dedicated telescope time each year

European surveillance of infections in cancer patients - ESIC

Major advances in cancer therapy result from development of multidrug chemotherapy regimens. Besides death from tumor progression, infections are currently one of the major causes of mortality and morbidity. Because of the risk of complications and mortality, the treatment for febrile neutropenia is admission to hospital and administration of broad-spectrum antibiotics. Response rates of initial antimicrobial treatment vary considerably (40-92%). Due to the heterogeneity of populations in randomized studies, comparison of efficacy and identification of risk factors is limited. This is the main reason why the European Society of Biomodulation and Chemotherapy (ESBiC) is conducting a surveillance study that concentrates more on the evaluation of risk factors than on the therapeutic outcome of prospective randomized antimicrobial regimens: European Surveillance of Infections in Cancer Patients (ESIC). The present contribution is to determine which cancer patients are at low risk for fever, and can benefit from first-line treatment with treatment options such as monotherapy as well as on an outpatient basis

“Accelerating institutional funding of low-carbon investment: The potential for an investment emissions intensity tax”

To encourage a step change in private finance for low-carbon investment, we examine the potential of taxing institutional investment funds (investment emissions intensity taxation, IEIT) if the emissions intensity of their portfolios exceeds specified thresholds. We examine how IEIT would impacts assets' relative expected rates of return, using a hypothetical diversified portfolio comprising the constituents of a leading market index. IEIT exerts a price influence on the flow of corporate capital expenditures financed either by capital-raising or by corporate retained earnings, encouraging both standalone low-carbon projects and more energy-efficient replacement of process-embedded fixed assets. IEIT must be a forward-looking tax with a pre-specified profile of reducing emissions intensity threshold levels to avoid potential offshoring of investment due to its significant impact on the cost of capital for high emissions intensity companies. IEIT challenges regulated investors to match their net zero declarations with actions, and acts as a policy backstop if emissions trading prices and coverage remain too low, or in case climate risk disclosure and investment taxonomy policies alone do not shift investment behaviours sufficiently

Extensions of Superscaling from Relativistic Mean Field Theory: the SuSAv2 Model

We present a systematic analysis of the quasielastic scaling functions computed within the Relativistic Mean Field (RMF) Theory and we propose an extension of the SuperScaling Approach (SuSA) model based on these results. The main aim of this work is to develop a realistic and accurate phenomenological model (SuSAv2), which incorporates the different RMF effects in the longitudinal and transverse nuclear responses, as well as in the isovector and isoscalar channels. This provides a complete set of reference scaling functions to describe in a consistent way both $(e, e')$ processes and the neutrino/antineutrino-nucleus reactions in the quasielastic region. A comparison of the model predictions with electron and neutrino scattering data is presented.Comment: 19 pages, 24 figure

Neutrino and antineutrino CCQE scattering in the SuperScaling Approximation from MiniBooNE to NOMAD energies

We compare the predictions of the SuperScaling model for charged current quasielastic muonic neutrino and antineutrino scattering from $^{12}$C with experimental data spanning an energy range up to 100 GeV. We discuss the sensitivity of the results to different parametrizations of the nucleon vector and axial-vector form factors. Finally, we show the differences between electron and muon (anti-)neutrino cross sections relevant for the $\nu$STORM facility.Comment: 14 pages, 7 figures; v2: small corrections in the text and two added references; version accepted for publication by Phys. Lett.

Thermodynamic inequalities in superfluid

We investigate general thermodynamic stability conditions for the superfluid. This analysis is performed in an extended space of thermodynamic variables containing (along with the usual thermodynamic coordinates such as pressure and temperature) superfluid velocity and momentum density. The stability conditions lead to thermodynamic inequalities which replace the Landau superfluidity criterion at finite temperatures.Comment: 7 pages, 1 figur