25,456 research outputs found
Sharp rate of average decay of the Fourier transform of a bounded set
We prove that the spherical mean of the Fourier transform of the
characteristic function of a bounded convex set (without any additional
assumptions) or a bounded set with a C^{3/2} boundary decays at infinity at the
same rate as the Fourier transform of the characteristic function of the ball.Comment: 10 pages. GAFA (to appear
Investigation of nonlinear motion simulator washout schemes
An overview is presented of some of the promising washout schemes which have been devised. The four schemes presented fall into two basic configurations; crossfeed and crossproduct. Various nonlinear modifications further differentiate the four schemes. One nonlinear scheme is discussed in detail. This washout scheme takes advantage of subliminal motions to speed up simulator cab centering. It exploits so-called perceptual indifference thresholds to center the simulator cab at a faster rate whenever the input to the simulator is below the perceptual indifference level. The effect is to reduce the angular and translational simulation motion by comparison with that for the linear washout case. Finally, the conclusions and implications for further research in the area of nonlinear washout filters are presented
Intensity dependence of Rydberg states
We investigate numerically and analytically the intensity dependence of the
fraction of electrons that end up in a Rydberg state after strong-field
ionization with linearly polarized light. We find that including the intensity
dependent distribution of ionization times and non-adiabatic effects leads to a
better understanding of experimental results. Furthermore, we observe using
Classical Trajectory Monte Carlo simulations that the intensity dependence of
the Rydberg yield changes with wavelength and that the previously observed
power-law dependence breaks down at longer wavelengths. Our work suggests that
Rydberg yield measurements can be used as an independent test for
non-adiabaticity in strong field ionization
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