Kaluza–Klein modes of bulk fields in a generalized Randall–Sundrum scenario

We consider a generalised two brane Randall–Sundrum model with non-zero cosmological constant on the visible TeV brane. Massive Kaluza–Klein modes for various bulk fields namely graviton, gauge field and antisymmetric second rank Kalb–Ramond field in a such generalized Randall–Sundrum scenario are determined. The masses for the Kaluza–Klein excitations of different bulk fields are found to depend on the brane cosmological constant indicating interesting consequences in warped brane particle phenomenology.     

Randall–Sundrum reality at the LHC

The radion is expected to be the first signal of the Randall–Sundrum (RS) model. We explore the possibility of finding it in the ongoing Higgs searches at the LHC. The little RS model (LRS), which has a fundamental scale at ∼¹⁰³$\sim {10}^3$ TeV, is excluded over wide ranges of the radion mass from the latest WW and γγ data by ATLAS and CMS.     

Two 3-branes in Randall–Sundrum setup and current acceleration of the universe

Five-dimensional spacetimes of two orbifold 3-branes are studied, by assuming that the two 3-branes are spatially homogeneous, isotropic, and independent of time  , following the so-called “bulk-based” approach. The most general form of the metric is obtained, and the corresponding field equations are divided into three groups, one is valid on each of the two 3-branes, and the third is valid in the bulk. The Einstein tensor on the 3-branes is expressed in terms of the discontinuities of the first-order derivatives of the metric coefficients. Thus, once the metric is known in the bulk, the distribution of the Einstein tensor on the two 3-branes is uniquely determined. As applications, we consider two different cases, one is in which the bulk is locally AdS₅${\mathit{AdS}}_5$, and the other is where it is vacuum. In some cases, it is shown that the universe is first decelerating and then accelerating. The global structure of the bulk as well as the 3-branes is also studied, and found that in some cases the solutions may represent the collision of two orbifold 3-branes. The applications of the formulas to the studies of the cyclic universe and the cosmological constant problem are also pointed out.     

Randall–Sundrum II model from small field inflation in light of planck data and reheating temperature

We focus on the behaviours of small field of an arctangent potential form, in Randall–Sundrum II braneworld. Within this framework, there is only one brane with positive tension while the second membrane is sent to infinity, and the configuration the model allows to localize the gravity on the curvature of the bulk. In that context, we found that inflationary observables (n _s, r, and dn _s/dlnk) depend only on the e-folding number N. From the power perturbation value P _R (k) given by the latest observational measurements, we evaluate the values of brane tension λ and the energy scale V ₀, and we have shown that the various inflationary perturbation parameters are widely consistent with the recent Planck data for a suitable choice of value of the number N. Concerning the reheating phase, we found a large value of the temperature T _re ～ 5 × 10¹⁴ GeV.     

Exchange bias in a generalized Meiklejohn–Bean approach

A generalized Meiklejohn–Bean model is considered in order to derive an analytic expression for the dependence of the exchange bias field on the layer thickness involved in ferromagnetic/antiferromagnetic heterosystems, on the orientation of the applied magnetic field with respect to the magnetic easy axes and on the quenched magnetization M_AF of the antiferromagnetic pinning layer. While M_AF is a well-known feature of field-cooled dilute antiferromagnets, it seems to occur quite generally also in pure AF pinning substrates. The new analytic expressions are successfully compared with recent experimental results and Monte Carlo investigations.     

Domain walls in a generalized Chern–Simons model

In this paper we study the structure of one dimensional topological solitons in a generalized Abelian-Higgs Chern–Simons model where the kinetic term is non-canonical. We present an example of an analytical self-dual electrically charged soliton solution which has a finite momentum per unit length along its direction. We compared the physical properties of our soliton with those for wall of Jackiw–Lee–Weinberg wall presented in Jackiw et al. (Phys. Rev. D 42:3488, 1990) to conclude that the non-canonical kinetic term can make the wall “thicker” redistributing uniformly the momentum flow along it.     

About Landau–Hopf scenario in a system of coupled self-oscillators

The conditions are discussed for which an ensemble of interacting oscillators may demonstrate the Landau–Hopf scenario of successive birth of multi-frequency quasi-periodic motions. A model is proposed that is a network of five globally coupled oscillators characterized by controlled degree of activation of individual oscillators. Illustrations are given for successive birth of tori of increasing dimension via quasi-periodic Hopf bifurcations.     

Energy–momentum tensor for the electromagnetic field in a dielectric

The total momentum of a thermodynamically closed system is unique, as is the total energy. Nevertheless, there is continuing confusion concerning the correct form of the momentum and the energy–momentum tensor for an electromagnetic field interacting with a linear dielectric medium. Rather than construct a total momentum from the Abraham momentum or the Minkowski momentum, we define a thermodynamically closed system consisting of a propagating electromagnetic field and a negligibly reflecting dielectric and we identify the Gordon momentum as the conserved total momentum by the fact that it is invariant in time. In the formalism of classical continuum electrodynamics, the Gordon momentum is therefore the unique representation of the total momentum in terms of the macroscopic electromagnetic fields and the macroscopic refractive index that characterizes the material. We also construct continuity equations for the energy and the Gordon momentum, noting that a time variable transformation is necessary to write the continuity equations in terms of the densities of conserved quantities. Finally, we use the continuity equations and the time–coordinate transformation to construct an array that has the properties of a traceless, symmetric energy–momentum tensor.     

Transition between extinction and blow-up in a generalized Fisher–KPP model

Stationary solutions of the Fisher–KPP equation with general nonlinear diffusion and arbitrary reactional kinetic orders terms are characterized. Such stationary (separatrix-like) solutions disjoint the blow-up solutions from those showing extinction. In addition a criterion for general parameter values is presented, which allows determining the blow-up or vanishing character of the solutions.     

The Timoshenko–Reissner generalized model of a plate highly nonuniform in thickness

A thin plate fabricated of material that is transversally isotropic and nonuniform in thickness is considered. The model of the monolayer transversally homogeneous isotropic plate, which is approximately equivalent to a thickness-nonuniform plate in the deflection and in the lowest frequencies of free vibrations, is constructed. The range of applicability of the model constructed is very wide. The main result of this study is a formula for calculating the transverse-shear rigidity of an equivalent transversally isotropic plate.     

Berry phase in a generalized nonlinear two-level system

In this paper, we investigate the behaviour of the geometric phase of a more generalized nonlinear system composed of an effective two-level system interacting with a single-mode quantized cavity field. Both the field nonlinearity and the atom-field coupling nonlinearity are considered. We find that the geometric phase depends on whether the index k is an odd number or an even number in the resonant case. In addition, we also find that the geometric phase may be easily observed when the field nonlinearity is not considered. The fractional statistical phenomenon appears in this system if the strong nonlinear atom-field coupling is considered. We have also investigated the geometric phase of an effective two-level system interacting with a two-mode quantized cavity field.     

Self-dual connections and the equations of fundamental fields in a Weyl–Cartan space

Spaces with a Weyl-type connection and torsion of a special type that are determined by the structure of the differentiability conditions in the algebra of complex quaternions are considered. These conditions are consistent only if the curvature of the connection is self-dual. The Maxwell and SL(2,?) Yang–Mills fields associated with the irreducible components of the connection also turn out to be self-dual, so that the corresponding equations are fulfilled on the solutions of the generating system. Using the twistor structure of the latter, its general solution is obtained. The singular locus has a string-like (particle-like) structure generating the self-consistent algebraic dynamics of the string system.     

Response of a uniformly accelerated detector to massless Rarita–Schwinger fields in vacuum

We study the response of a uniformly accelerated detector modeled by a two-level atom nonlinearly coupled to vacuum massless Rarita–Schwinger fields. We first generalize the formalism developed by Dalibard, Dupont-Roc, and Cohen-Tannoudji in the linear coupling case, and we then calculate the mean rate of change of the atomic energy of the accelerated atom. Our result shows that a uniformly accelerated atom in its ground state interacting with vacuum Rarita–Schwinger field fluctuations would spontaneously transition to an excited state and the unique feature in contrast to the case of the atom coupled to the scalar, electromagnetic and Dirac fields is the appearance of terms in the excitation rate which are proportional to the sixth and eighth powers of acceleration.     

Isothermal martensitic transformation in a 12Cr–9Ni–4Mo–2Cu stainless steel in applied magnetic fields

This work concerns an in situ study of the isothermal formation of martensite in a stainless steel under the influence of magnetic fields up to 9 T at three different temperatures (213, 233 and 253 K). It is shown that the presence of a constant applied magnetic field promotes the formation of martensite significantly. The activation energy for the nucleation of martensite has been derived using a semi-empirical kinetic model. The experimental results have been analyzed using the Ghosh and Olson model. While this model describes the time and field dependences of the experimental data well, the thermal frictional energy and the defect size values are much lower than those expected from earlier work.