Optical realization of nonlinear quantum dynamics

In a cavity filled with a Kerr medium it is possible to generate the superposition of coherent states, i.e. Schroodinger cat states may be realized in this system. We show that such a medium may be mimicked by the propagation of a conveniently shaped Gaussian beam in a GRIN device. This is attained by introducing a second order correction to the paraxial propagation of the beam. An additional result is that a Gaussian beam propagating in GRIN media, may split into two Gaussian beams

Solitary-wave vortices in quadratic nonlinear media

We find families of vortex solitary waves in bulk quadratic nonlinear media under conditions for second-harmonic generation. We show that the vortex solitary waves are azimuthally unstable and that they decay into sets of stable spatial solitons. We calculate the growth rates of the azimuthal perturbations and show how those affect the pattern of output light. © 1998 Optical Society of AmericaPeer ReviewedPostprint (published version

Running Gluon Mass from Landau Gauge Lattice QCD Propagator

The interpretation of the Landau gauge lattice gluon propagator as a massive type bosonic propagator is investigated. Three different scenarios are discussed: i) an infrared constant gluon mass; ii) an ultraviolet constant gluon mass; iii) a momentum dependent mass. We find that the infrared data can be associated with a massive propagator up to momenta $\sim 500$ MeV, with a constant gluon mass of 723(11) MeV, if one excludes the zero momentum gluon propagator from the analysis, or 648(7) MeV, if the zero momentum gluon propagator is included in the data sets. The ultraviolet lattice data is not compatible with a massive type propagator with a constant mass. The scenario of a momentum dependent gluon mass gives a decreasing mass with the momentum, which vanishes in the deep ultraviolet region. Furthermore, we show that the functional forms used to describe the decoupling like solution of the Dyson-Schwinger equations are compatible with the lattice data with similar mass scales.Comment: Version to appear in J. Phys. G. New version include some rewriting and new analysis. In particular, the section on the running mass is ne

Modificaciones de curva velocidad-tiempo de la cadera en el estilo braza a distintas velocidades de nado

El propósito del presente estudio fue observar cual era el comportamiento de la curva de velocidad de la cadera durante el nado estilo braza a diferentes velocidades de nado. Dos nadadoras de distinto nivel fueron seleccionadas para participar en el presente estudio en el que realizaron cuatro repeticiones de 25 m a velocidad diferente. Dos cámaras de vídeo PAL, una subacuática y otra exterior, fijas y perpendiculares a la dirección de desplazamiento del nadador, se emplearon para analizar un ciclo completo de nado de cada una de las repeticiones de nado. Se calcularon velocidades promedio de nado, velocidades máximas intra-ciclo, velocidades mínimas intra-ciclo, frecuencias, longitudes y duración de ciclo. Se encontró que al incrementar la velocidad promedio de nado, los valores máximos intra-ciclo aumentaban, no observándose modificación alguna en el valor mínimo. Además se observó un aumento de la frecuencia de ciclo y una disminución de la longitud de ciclo a medida que la velocidad se incrementaba, debido a la reducción del tiempo de deslizamiento tras la patada

Ghost-gluon coupling, power corrections and ΛMSˉ\Lambda_{\bar{MS}} from twisted-mass lattice QCD at Nf=2N_f=2

A non-perturbative calculation of the ghost-gluon running QCD coupling constant is performed using $N_f=2$ twisted-mass dynamical fermions. The extraction of $\Lambda_{\bar{MS}}$ in the chiral limit reveals the presence of a non-perturbative OPE contribution that is assumed to be dominated by a dimension-two \VEV{A^2} condensate. In this contest a novel method for calibrating the lattice spacing in lattice simulations is presented.Comment: 7 pages, 4 figures, XXVIII International Symposium on Lattice Field Theory 201