An analysis based on the comparison between singularities of speckle phase and pseudophase in the practice of optical vortex metrology is carried out by measuring the phase map of the speckle pattern obtained from the ...

We study solutions to a one-phase singular perturbation problem that arises in combustion theory and that formally approximates the classical one-phase free boundary problem. We introduce a natural density condition on the ...

It is considered the possibility of applying Padé approximants for the phase equation with singular potentials. Some examples are considered which show that it is possible to obtain good results. © 1970 Società Italiana di Fisica.

In this work, we present some results of Qualitative Theory of Planar Ordinary Differential Equations employed in the investigation of the behavior of solutions in the neighborhood of semi-hyperbolic and nilpotent singularities.

We show that the key ingredients for creating recurrent traveling spatial phase defects in drifting patterns are a noise-sustained structure regime together with the vicinity of a phase transition, that is, a spatial region ...

Due to the isotropic edge enhancement, the vortex phase filters are of commonly used in spatial filtering. In general, these filters employ a spiral phase mask on the Fourier plane, the square modulo from this convolution ...

In this paper we study the phase portraits in the Poincaré disk of the reversible vector fields of type (2;0) having generic bifurcations around a symmetric singular point p. We also prove the nonexistence of any periodic ...