Anomalous spatio-temporal chaos in a two-dimensional system of non-locally coupled oscillators

A two-dimensional system of non-locally coupled complex Ginzburg-Landau oscillators is investigated numerically for the first time. As already known for the one-dimensional case, the system exhibits anomalous spatio-temporal chaos characterized by power-law spatial correlations. In this chaotic regime, the amplitude difference between neighboring elements shows temporal noisy on-off intermittency. The system is also spatially intermittent in this regime, which is revealed by multi-scaling analysis; the amplitude field is multi-affine and the difference field is multi-fractal. Correspondingly, the probability distribution function of the measure defined for each field is strongly non-Gaussian, showing scale-dependent deviations in the tails due to intermittency.Comment: 9 pages, 14 figures, submitted to Chao

Phase description of oscillatory convection with a spatially translational mode

We formulate a theory for the phase description of oscillatory convection in a cylindrical Hele-Shaw cell that is laterally periodic. This system possesses spatial translational symmetry in the lateral direction owing to the cylindrical shape as well as temporal translational symmetry. Oscillatory convection in this system is described by a limit-torus solution that possesses two phase modes; one is a spatial phase and the other is a temporal phase. The spatial and temporal phases indicate the position and oscillation of the convection, respectively. The theory developed in this paper can be considered as a phase reduction method for limit-torus solutions in infinite-dimensional dynamical systems, namely, limit-torus solutions to partial differential equations representing oscillatory convection with a spatially translational mode. We derive the phase sensitivity functions for spatial and temporal phases; these functions quantify the phase responses of the oscillatory convection to weak perturbations applied at each spatial point. Using the phase sensitivity functions, we characterize the spatiotemporal phase responses of oscillatory convection to weak spatial stimuli and analyze the spatiotemporal phase synchronization between weakly coupled systems of oscillatory convection.Comment: 35 pages, 14 figures. Generalizes the phase description method developed in arXiv:1110.112

ICT Capital-Skill Complementarity and Wage Inequality: Evidence from OECD Countries

Although wage inequality has evolved in advanced countries over recent decades, it is unknown the extent to which the evolution of wage inequality is attributable to observed factors such as capital and labor quantities or unobserved factors such as labor-augmenting technology. To examine this issue, we estimate an aggregate production function extended to allow for capital-skill complementarity and factor-biased technological change using cross-country panel data and the shift-share instrument. Our results indicate that most of the changes in the skill premium are attributed to observed factors including ICT equipment in the majority of OECD countries

Asymmetric Ejecta Distribution in SN 1006

We present the results from deep X-ray observations (~400 ks in total) of SN 1006 by the X-ray astronomy satellite Suzaku. The thermal spectrum from the entire supernova remnant (SNR) exhibits prominent emission lines of O, Ne, Mg, Si, S, Ar, Ca, and Fe. The observed abundance pattern in the ejecta components is in good agreement with that predicted by a standard model of Type Ia supernovae (SNe). The spatially resolved analysis reveals that the distribution of the O-burning and incomplete Si-burning products (Si, S, and Ar) is asymmetric, while that of the C-burning products (O, Ne, and Mg) is relatively uniform in the SNR interior. The peak position of the former is clearly shifted by 5' (~3.2 pc at a distance of 2.2 kpc) to the southeast from the SNR's geometric center. Using the SNR age of ~1000 yr, we constrain the velocity asymmetry (in projection) of ejecta to be ~3100 km/s. The abundance of Fe is also significantly higher in the southeast region than in the northwest region. Given that the non-uniformity is observed only among the heavier elements (Si through Fe), we argue that SN 1006 originates from an asymmetric explosion, as is expected from recent multi-dimensional simulations of Type Ia SNe, although we cannot eliminate the possibility that an inhomogeneous ambient medium induced the apparent non-uniformity. Possible evidence for the Cr K-shell line and line broadening in the Fe K-shell emission is also found.Comment: 11 pages, 12 figures, 4 tables, formatted using emulateapj.cls. Accepted for publication in Ap