Corrections to scaling in entanglement entropy from boundary perturbations

We investigate the corrections to scaling of the Renyi entropies of a region of size l at the end of a semi-infinite one-dimensional system described by a conformal field theory when the corrections come from irrelevant boundary operators. The corrections from irrelevant bulk operators with scaling dimension x have been studied by Cardy and Calabrese (2010), and they found not only the expected corrections of the form l^(4-2x) but also unusual corrections that could not have been anticipated by finite-size scaling arguments alone. However, for the case of perturbations from irrelevant boundary operators we find that the only corrections that can occur to leading order are of the form l^(2-2x_b) for boundary operators with scaling dimension x_b < 3/2, and l^(-1) when x_b > 3/2. When x_b=3/2 they are of the form l^(-1)log(l). A marginally irrelevant boundary perturbation will give leading corrections going as log(l)^(-3). No unusual corrections occur when perturbing with a boundary operator.Comment: 8 pages. Minor improvements and updated references. Published versio

PAR13: HYPOTHETICAL VERSUS REAL WILLINGNESS TO PAY IN THE HEALTH CARE SECTOR: RESULTS FROM A FIELD EXPERIMENT

How does the brain carry out working memory storage, categorization, and voluntary performance of event sequences? The LIST PARSE neural model proposes an answer to this question that unifies the explanation of cognitive, neurophysiological, and anatomical data from humans and monkeys. It quantitatively simulates human cognitive data about immediate serial recall and free recall, and monkey neurophysiological data from the prefrontal cortex obtained during sequential sensory-motor imitation and planned performance. The model clarifies why both spatial and non-spatial working memories share the same type of circuit design. It proposes how the laminar circuits of lateral prefrontal cortex carry out working memory storage of event sequences within layers 6 and 4, how these event sequences are unitized through learning into list chunks within layer 2/3, and how these stored sequences can be recalled at variable rates that are under volitional control by the basal ganglia. These laminar prefrontal circuits are variations of laminar circuits in the visual cortex that have been used to explain data about how the brain sees. These examples from visual and prefrontal cortex illustrate how laminar neocortex can represent both spatial and temporal information, and open the way towards understanding how other behaviors may be represented and controlled by variations on a shared laminar neocortical design.National Science Foundation (SBE-0354378); Office of Naval Research (N00014-01-1-0624, N00014-95-1-0409

Mechanical reliability analysis of flexible power cables for marine energy

Marine power cables connected to moving devices at sea may experience millions of load\ua0cycles per year, and thus they need to be flexible due to the movements of the cable and designed for\ua0mechanical loads. In this study, the focus is on the mechanical life of flexible low- and medium voltage\ua0power cables connecting devices to hubs. The reliability design method Variational Mode and Effect\ua0Analysis (VMEA) is applied, based on identifying and quantifying different types of uncertainty\ua0sources, including scatter, model and statistical uncertainties. It implements a load–strength approach\ua0that combines numerical simulations to assess the loads on the cable and experimental tests to\ua0assess the strength of the cable. The VMEA method is demonstrated for an evaluation of bending\ua0fatigue, and is found to be a useful tool to evaluate uncertainties in fatigue life for WEC (Wave Energy Converter) system cables during the design phase. The results give a firm foundation for the\ua0evaluation of safety against fatigue and are also helpful for identifying weak spots in the reliability\ua0assessment, thereby motivating actions in the improvement process. Uncertainties in terms of scatter,\ua0statistical uncertainty and model uncertainty are evaluated with respect to theWaveEL 3.0, a WEC\ua0designed by the companyWaves4Power, and deployed in Runde, Norway. A major contribution to\ua0the overall uncertainty is found to originate from the fatigue life model, both in terms of scatter and\ua0model uncertainty

Enhanced Two-Channel Kondo Physics in a Quantum Box Device

We propose a design for a one-dimensional quantum box device where the charge fluctuations are described by an anisotropic two-channel Kondo model. The device consists of a quantum box in the Coulomb blockade regime, weakly coupled to a quantum wire by a single-mode point contact. The electron correlations in the wire produce strong back scattering at the contact, significantly increasing the Kondo temperature as compared to the case of non-interacting electrons. By employing boundary conformal field theory techniques we show that the differential capacitance of the box exhibits manifest two-channel Kondo scaling with temperature and gate voltage, uncontaminated by the one-dimensional electron correlations. We discuss the prospect to experimentally access the Kondo regime with this type of device.Comment: EPL style, 5 pages, 1 figure, final published versio

Bubble Growth in Superfluid 3-He: The Dynamics of the Curved A-B Interface

We study the hydrodynamics of the A-B interface with finite curvature. The interface tension is shown to enhance both the transition velocity and the amplitudes of second sound. In addition, the magnetic signals emitted by the growing bubble are calculated, and the interaction between many growing bubbles is considered.Comment: 20 pages, 3 figures, LaTeX, ITP-UH 11/9

Description of a quantum convolutional code

We describe a quantum error correction scheme aimed at protecting a flow of quantum information over long distance communication. It is largely inspired by the theory of classical convolutional codes which are used in similar circumstances in classical communication. The particular example shown here uses the stabilizer formalism, which provides an explicit encoding circuit. An associated error estimation algorithm is given explicitly and shown to provide the most likely error over any memoryless quantum channel, while its complexity grows only linearly with the number of encoded qubits.Comment: 4 pages, uses revtex4. Minor correction in the encoding and decoding circuit

An enhanced stochastic operating cycle description including weather and traffic models

The present paper extends the concept of a stochastic operating cycle (sOC) by introducing additional models for weather and traffic. In regard to the weather parameters, dynamic models for air temperature, atmospheric pressure, relative humidity, precipitation, wind speed and direction are included. The traffic models is instead based on a macroscopic approach which describes the density dynamically by means of a simple autoregressive process. The enhanced format is structured in a hierarchical fashion, allowing for ease of implementation and modularity. The novel models are parametrised starting from data available from external databases. The possibility of generating synthetic data using the statistical descriptors introduced in the paper is also discussed.To investigate the impact of the novel parameters over energy efficiency, a sensitivity analysis is conducted with a combinatorial test design. Simulation results show that both seasonality and traffic conditions are responsible for introducing major variations in the\ua0CO2\ua0emissions