15,289 research outputs found

    An effective-field-theory analysis of Efimov physics in heteronuclear mixtures of ultracold atomic gases

    Full text link
    We use an effective-field-theory framework to analyze the Efimov effect in heteronuclear three-body systems consisting of two species of atoms with a large interspecies scattering length. In the leading-order description of this theory, various three-body observables in heteronuclear mixtures can be universally parameterized by one three-body parameter. We present the next-to-leading corrections, which include the effects of the finite interspecies effective range and the finite intraspecies scattering length, to various three-body observables. We show that only one additional three-body parameter is required to render the theory predictive at this order. By including the effective range and intraspecies scattering length corrections, we derive a set of universal relations that connect the different Efimov features near the interspecies Feshbach resonance. Furthermore, we show that these relations can be interpreted in terms of the running of the three-body counterterms that naturally emerge from proper renormalization. Finally, we make predictions for recombination observables of a number of atomic systems that are of experimental interest.Comment: peer-reviewed and edited version, errors fixe

    Perampanel inhibition of AMPA receptor currents in cultured hippocampal neurons.

    Get PDF
    Perampanel is an aryl substituted 2-pyridone AMPA receptor antagonist that was recently approved as a treatment for epilepsy. The drug potently inhibits AMPA receptor responses but the mode of block has not been characterized. Here the action of perampanel on AMPA receptors was investigated by whole-cell voltage-clamp recording in cultured rat hippocampal neurons. Perampanel caused a slow (Ļ„āˆ¼1 s at 3 ĀµM), concentration-dependent inhibition of AMPA receptor currents evoked by AMPA and kainate. The rates of block and unblock of AMPA receptor currents were 1.5Ɨ105 M-1 s-1 and 0.58 s-1, respectively. Perampanel did not affect NMDA receptor currents. The extent of block of non-desensitizing kainate-evoked currents (IC50, 0.56 ĀµM) was similar at all kainate concentrations (3-100 ĀµM), demonstrating a noncompetitive blocking action. Parampanel did not alter the trajectory of AMPA evoked currents indicating that it does not influence AMPA receptor desensitization. Perampanel is a selective negative allosteric AMPA receptor antagonist of high-affinity and slow blocking kinetics

    Semiformal Verification of Embedded Software in Medical Devices Considering Stringent Hardware Constraints

    No full text
    In recent days, the complexity of software has increased significantly in embedded products in such a way that the verification of Embedded Software (ESW) now plays an important role to ensure the product's quality. Embedded systems engineers usually face the problems of verifying properties that have to meet the application's deadline, access the memory region, handle concurrency, and control the hardware registers. This work proposes a semiformal verification approach that combines dynamic and static verification to stress and cover exhaustively the state space of the system. We perform a case study on embedded software used in the medical devices domain. We conclude that the proposed approach improves the coverage and reduces substantially the verification time

    A generalized PĆ³lya's urn with graph based interactions: convergence at linearity

    Get PDF
    We consider a special case of the generalized Polya's urn model introduced in 3]. Given a finite connected graph G, place a bin at each vertex. Two bins are called a pair if they share an edge of G. At discrete times, a ball is added to each pair of bins. In a pair of bins, one of the bins gets the ball with probability proportional to its current number of balls. A question of essential interest for the model is to understand the limiting behavior of the proportion of balls in the bins for different graphs G. In this paper, we present two results regarding this question. If G is not balanced-bipartite, we prove that the proportion of balls converges to some deterministic point v = v (G) almost surely. If G is regular bipartite, we prove that the proportion of balls converges to a point in some explicit interval almost surely. The question of convergence remains open in the case when G is non-regular balanced-bipartite

    Finite Speed of Quantum Scrambling with Long Range Interactions

    Get PDF
    In a locally interacting many-body system, two isolated qubits, separated by a large distance r, become correlated and entangled with each other at a time tā‰„r/v. This finite speed v of quantum information scrambling limits quantum information processing, thermalization, and even equilibrium correlations. Yet most experimental systems contain long range power-law interactionsā€”qubits separated by r have potential energy V(r)āˆr^(āˆ’Ī±). Examples include the long range Coulomb interactions in plasma (Ī±=1) and dipolar interactions between spins (Ī±=3). In one spatial dimension, we prove that the speed of quantum scrambling remains finite for sufficiently large Ī±. This result parametrically improves previous bounds, compares favorably with recent numerical simulations, and can be realized in quantum simulators with dipolar interactions. Our new mathematical methods lead to improved algorithms for classically simulating quantum systems, and improve bounds on environmental decoherence in experimental quantum information processors
    • ā€¦
    corecore