We introduce the orbital Stokes parameters as a linear combination of a beam's second-order moments. Similar to the ones describing the field polarization and associated with beam energy and its spin angular momentum, the orbital Stokes parameters are related to the total beam width and its orbital angular momentum. We derive the transformation laws for these parameters during beam propagation ...

The notion of the rotational frequency shift, an analog of the Doppler shift, is introduced. This new frequency shift occurs for atomic systems that lack rotational invariance, but have stationary states in a rotating frame. The rotational frequency shift is given by the scalar product of the angular velocity and the angular momentum of the emitted photon in full analogy with the standard Doppl...

We report the bright solitons of the generalized Gross-Pitaevskii (GP) equation with some types of physically relevant parity-time- ( PT-) and non- PT-symmetric potentials. We find that the constant momentum coefficient Γ can modulate the linear stability and complicated transverse power-flows (not always from the gain toward loss) of nonlinear modes. However, the varying momentum coefficient Γ...

Mesoscale circulations induced by complex land surface have been investigated using linear stochastic models and a nonlinear numerical model. Random distributions of differential surface heating and variable topography are described in terms of homogeneous random fields. Analytical solutions for the linear atmospheric systems under these random surface forcings have been obtained. The stochasti...

We propose a simpler model in order to facilitate calculations of the Feynman paradox concerning the angular momentum of a static electromagnetic field. When an angular momentum is attached to the static electromagnetic field the paradox disappears. The storage of the angular momentum in the field during the assembling process is also analysed, It is well known that, for systems of particles sa...

in this paper, free convection in an inclined stepped chamber has been studied. one wall of this enclosure is kept cold and the opposite wall equipped with constant heat source. the remaining walls are maintained adiabatic. there is one adiabatic step on the bottom wall. the aim of the present study is to forecast the effect of raleigh number, slope of enclosure, step dimension, and heat source...

‎the problem of two-phase mhd boundary layer flow, heat and mass transfer over a stretching sheet with fluid-particle suspension and thermal radiation has been studied. the effect of mass transfer in dusty fluid over a stretching sheet is considered for the first time. the governing equations are reduced to a set of non-linear ordinary differential equations under suitable similarity transforma...

Uniform three-dimensional ellipsoidal distributions of charge are the ultimate goal in charged particle accelerator physics because of their linear internal force fields. Such bunches remain ellipsoidal with perfectly linear position-momentum phase space correlations in any linear transport system. We present a method, based on photoemission by radially shaped femtosecond laser pulses, to actua...

In 1969 Aharonov, Pend leton and Petersen introduced a new dynamical variable, the modular momentum, and discussed how several nonlDcal interactions could be characterized as resulting from its exchange. In this paper we review and extend their approach by applying it to the Aharonov~Bohm effect with an electromagnetic scalar potential. First we review the nonclassical nature of the effect, sho...