abstract

Under normal operations, memristive devices undergo variability in time and space and have internal dynamics. Interplay of memory and stochastic signal processing in memristive devices makes them candidates for performing bio-inspired tasks of information transduction and transformation, where intrinsic random behavior can be harnessed for high performance of circuits built up of individual memory storing elements. The paper discusses models of single memristive devices exhibiting both — dynamic hysteresis and Stochastic Resonance, addressing also the cooperative effect of correlated noises acting on the system and occurrence of dirty hysteretic rounding.

abstract

We consider \(N\) Dirac fermions on a 4-dimensional Euclidean space with a quadratic interaction given by arbitrary external Clifford-valued fields. The divergence of the axial current satisfies on the classical level a relation that is violated after quantization. Using the Pauli–Villars method to regularize the fields, we find the conditions that guarantee the finiteness of the anomaly. We also find this anomaly. Our result generalizes the well-known computation of axial anomaly of Dirac fermions interacting with an external Yang–Mills field.

abstract

A kinetic model for the dynamics of collisionless spin neutral particles in a spacetime with torsion is proposed. The fundamental matter field is the kinetic density \(f(x,u,s)\) of particles with four-velocity \(u\) and four-spin \(s\). The stress-energy tensor and the spin current of the particles distribution are defined as suitable integral moments of \(f\) in the \((u,s)\) variables. By requiring compatibility with the contracted Bianchi identity in Einstein–Cartan theory, we derive a transport equation on the kinetic density \(f\) that generalizes the well-known Vlasov equation for spinless particles. The total number of particles in the new model is not conserved. To restore this important property, we assume the existence in spacetime of a second species of particles with the same mass and spin magnitude. The Vlasov equation on the kinetic density \(\bar {f}\) of the new particles is derived by requiring that the sum of the total numbers of particles of the two species should be conserved.

abstract

The mirror energy difference is a mainly noticeable in isospin symmetry breaking, containing important facts about the nuclear structure. From the examination of these differences, several nuclear structure properties can be studied. Thus, in this work, the binding energy differences of mirror nuclei with \(A=23\), 25, and 27 are investigated in terms of the Hartree–Fock (HF) calculations with Skxta, Sly4, and Skxs25 Skyrme parameterizations. \(\beta ^+\)-decay energy \(E(\beta ^+)\) and the nuclear radius parameter of \(^{23}\)Na, \(^{25}\)Mg, and \(^{27}\)Al nuclei together with their mirror nuclei \(^{23}\)Mg, \(^{25}\)Al, and \(^{27}\)Si are calculated, followed by a regular investigation of the binding energy difference. The calculated values of the nuclear radius parameter are in good agreement with those derived from mirror nuclei experiments. In addition, the ground-state density distributions, form factors, root mean square radii, and the relationship between the proton skin of a nucleus and the difference between the proton radii of mirror nuclei are studied. In general, a linear relationship between the proton skin and the difference in the proton radii between the mirror pair nuclei was observed