Giant Goos–Hänchen shifts and radiation-induced trapping of Helmholtz solitons at nonlinear interfaces

Giant Goos–Hänchen shifts and radiation-induced trapping are studied at the planar boundary separating two focusing Kerr media within the framework of the Helmholtz theory. The analysis, valid for all angles of incidence, reveals that interfaces exhibiting linear external refraction can also accommodate both phenomena. Numerical evidence of these effects is provided, based on analytical predictions derived from a generalized Snell’s law

Dark solitons at nonlinear interfaces

The refraction of dark solitons at a planar boundary separating two defocusing Kerr media is simulated and analyzed, for the first time (to our knowledge). Analysis is based on the nonlinear Helmholtz equation and is thus valid for any angle of incidence. A new law, governing refraction of black solitons, is combined with one describing bright soliton refraction to yield a generalized Snell’s law whose validity is verified numerically. The complexity of gray soliton refraction is also analyzed, and illustrated by a change from external to internal refraction on varying the soliton contrast parameter

Helmholtz solitons in diffusive Kerr-type media

Nonlinear interfaces separating two diffusive Kerr-type media exhibit dual switching between total internal reflection and transmission. This property is found within a weakly nonlocal regime when both a nonparaxial treatment of the problem and a full two-dimensional model for carrier diffusion are assumed. The theoretical model is shown to predict an effective cubic-quintic nonlinearity with competing terms that produces such property. The validity of the analysis is contrasted with a full set of numerical simulations

The inherent overlapping in the parallel calculation of the Laplacian

Producción CientíficaA new approach for the parallel computation of the Laplacian in the Fourier domain is presented. This numerical problem inherits the intrinsic sequencing involved in the calculation of any multidimensional Fast Fourier Transform (FFT) where blocking communications assure that its computation is strictly carried out dimension by dimension. Such data dependency vanishes when one considers the Laplacian as the sum of n independent one-dimensional kernels, so that computation and communication can be naturally overlapped with nonblocking communications. Overlapping is demonstrated to be responsible for the speedup figures we obtain when our approach is compared to state-of-the-art parallel multidimensional FFTs.Junta de Castilla León (grant number VA296P18

Estudio de senos craneales para la determinación del sexo

Se presenta un estudio sobre 106 cráneos pertenecientes a la Colección de la Escuela de Medicina Legal de Madrid, de población española actual y sexo conocido a fin de estudiar si existen diferencias en relación con el sexo en cuanto al número de lóbulos y el área en mm de los senos frontales. Se realiza estudio radiológico y de análisis de imagen concluyendo que no existen diferencias en varones y en mujeres en ninguno de los dos parámetros estudiados.We present a study about 106 crania which belong to the collection of the Legal Medicine School of Madrid, of current spanish population and known sex to study if there are diferences related with sex when it comes to talk about the number of lobes and the area in mm between the cranial sinus. A radiological and image analysis study is carried out concluding that there are no differences in male and female in both parametres studied