Scalar potential

About: Scalar potential is a research topic. Over the lifetime, 3642 publications have been published within this topic receiving 78868 citations. The topic is also known as: potential.

Nonlinearly charged black holes in the scalar-tensor modified gravity theory

Abstract: Starting from the action of the scalar-tensor modified gravity theory coupled to the power law nonlinear electrodynamics and making use of the suitable transformation relations, the corresponding action of the Einstein-power-Maxwell-dilaton gravity theory has been obtained. Thermodynamical properties of the new charged dilatonic black holes have been investigated in the presence of a power Maxwell field as the nonlinear electrodynamics. Making use of a special form of a scalar field, it has been found that the scalar potential can be written as the linear combination of three Liouville-type potentials. Three new classes of spherically symmetric charged dilatonic black hole solutions have been obtained as the exact solutions to the field equations of the Einstein-power-Maxwell-dilaton theory. The conserved and thermodynamical quantities, related to the new black hole solutions, have been calculated from geometrical and thermodynamical approaches separately. Through comparison of the results obtained from these two alternative approaches, the validity of the first law of black hole thermodynamics has been confirmed for either of three new black hole solutions. Thermal stability or phase transition of the new black hole solutions has been analyzed, making use of the canonical ensemble method, and by calculating the black hole heat capacity at the fixed black hole charge. The points of type one and type two phase transitions as well as the ranges at which the black holes are locally stable have been determined precisely. The nonlinearly charged string black hole solutions have been obtained from their Einstein's counterparts. The thermodynamical properties as well as the thermal stability of the new charged string black holes have been investigated by utilizing the canonical ensemble method.

No inner-horizon theorem for black holes with charged scalar hairs

Abstract: We establish a no inner-horizon theorem for black holes with charged scalar hairs. Considering a general gravitational theory with a charged scalar field, we prove that there exists no inner Cauchy horizon for both spherical and planar black holes with non-trivial scalar hair. The hairy black holes approach to a spacelike singularity at late interior time. This result is independent of the form of scalar potentials as well as the asymptotic boundary of spacetimes. We prove that the geometry near the singularity takes a universal Kasner form when the kinetic term of the scalar hair dominates, while novel behaviors different from the Kasner form are uncovered when the scalar potential become important to the background. For the hyperbolic horizon case, we show that hairy black hole can only has at most one inner horizon, and a concrete example with an inner horizon is presented. All these features are also valid for the Einstein gravity coupled with neutral scalars.

Vector Preisach hysteresis modeling: Measurement, identification and application

Abstract: The paper presents a Preisach model to simulate the vector hysteresis properties of ferromagnetic materials. The vector behavior has been studied using a single sheet tester with a disk-shaped specimen at low frequency. The locus of the magnetic flux density vector has been controlled by a digital measurement system. An inverse vector Preisach hysteresis model has been developed and identified by applying the measured data. Finally, the inverse model has been inserted into a finite element procedure through the fixed point technique and the reduced magnetic scalar potential formulation to simulate the measurement system. The applicability of the measurement system as well as the developed model has been proven by comparing measured and simulated results.

Scalar Deformations of Schwarzschild Holes and Their Stability

Abstract: We construct two solutions of the minimally coupled Einstein–scalar field equations, representing regular deformations of Schwarzschild black holes by a selfinteracting, static, scalar field. One solution features an exponentially decaying scalar field and a triple-well interaction potential; the other one is completely analytic and sprouts Coulomb-like scalar hair. Both evade the no-hair theorem by having partially negative potential, in conflict with the dominant energy condition. The linear perturbation theory around such backgrounds is developed in general, and yields ! !

Two-body Dirac equation with a scalar linear potential.

Abstract: A semirelativistic equation which describes the relative motion of a Dirac particle and its antiparticle, interacting through a scalar potential, linearly dependent on the relative distance, is investigated. The simplest case, corresponding to /sup 1/S/sub 0/ and /sup 3/P/sub 0/ solutions, of total angular momentum J = 0 and positive and negative parities, respectively, is easily worked out for massless constituents. The case of massive constituents, which gives rise to a different regime, is also examined together with other salient features of our approach. A treatment of the light- and heavy-meson J = 0 sectors is briefly discussed.