In this paper, we have obtained the plane wave like solutions of the Einstein-Maxwell equations in presence of null fluids and null currents with particular cases.

We show the existence, size and some absorbing properties of global attractors of the nonlinear wave equations with nonlinear dissipations like ρ(x, ut) = a(x)|ut|rut.

We consider the deformation of the Poincaré group in 2+1 dimensions into the quantum double of the Lorentz group and construct Lorentz-covariant momentum-space formulations of the irreducible representations describing massive particles with spin 0, 12 and 1 in the deformed theory. We discuss ways of obtaining non-commutative versions of relativistic wave equations like the Klein–Gordon, Dirac ...

A ‘covariant’ field that transforms like a relativistic field operator is required to be a linear combination of ‘canonical’ fields that transform like annihilation and creation operators and with invariant coefficients. The Invariant Coefficient Hypothesis contends that this familiar construction by itself yields useful results. Thus, just the transformation properties are considered here, not...

In this paper, longshore sediment transport in littoral zones is investigated. For investigation of sediment transport in the nearshore zone, the effects of waves, currents and topographical conditions of coast are considered. Linear wave theory was used for the investigation of the wave behaviour. Governing equations of littoral current are continuity and momentum ones. For calculating concent...

Rock-like materials are composites that can be regarded as a mixture composed of elastic, plastic, and viscous components. They exhibit viscoelastic-plastic behavior under a high-strain-rate loading according to element model theory. This paper presents an analytical solution for stress wave propagation in viscoelastic-plastic rock-like materials under a high-strain-rate loading and verifies th...

the study of wave and its propagation on the water surface is among significant phenomena in designing quay, marine and water structures. therefore, in order to design structures which are exposed to direct wave forces, it is necessary to study and simulate water surface height and the wave forces on the structures body in different boundary conditions. in this study, the propagation of static ...

We show that the spherically symmetric Einstein-scalar-field equations for wave-like decaying initial data at null infinity have unique local solutions and global small data. also generalize Christodoulou's generalized to emphasize this condition is sharp.