Halo mass function in scale invariant models

Sheth-Tormen mass function has been widely used to quantify the abundance of dark matter halos. It is a significant improvement over the Press-Schechter mass function as it uses ellipsoidal collapse in place of spherical collapse. Both of these mass functions can be written in a form that is universal, i.e., independent of cosmology and power spectrum when scaled in suitable variables. However, cosmological simulations have shown that this universality is approximate. In this paper, we investigate the power spectrum dependence of halo mass function through a suite of dark-matter-only N-body simulations of seven power-law models in an Einstein-de Sitter cosmology. This choice of cosmology and a power-law power spectrum ensures the self-similar evolution of dark matter distribution, allowing us to isolate the power spectrum dependence of mass function. We find that the mass function shows a clear non-universality. We present fits for the parameters of the Sheth-Tormen mass function for a range of power-law power-spectrum indices. We find a mild evolution in the overall shape of the mass function with the epoch. Finally, we extend our result to LCDM cosmology. We show that the Sheth-Tormen mass function with parameter values derived from a matched power-law EdS cosmology provides a better fit to the LCDM mass function than the standard Sheth-Tormen mass function. Our results indicate that an improved analytical theory is required to provide better fits to the mass function.Comment: 11 pages, 10 figures. This is a much expanded and upgraded version of 0908.2702. Submitted to MNRA

Affordable sensor based gaze tracking for realistic psychological assessment

by A. Sinha, R. Gavas, S. Roy, D. Chatterjee, S. Tripathy, K. Charaborty and Uttama Lahir

Affordable sensor based gaze tracking for realistic psychological assessment

by A. Sinha, R. Gavas, S. Roy, D. Chatterjee, S. Tripathy, K. Charaborty and Uttama Lahir

Study on forming tool module with variable stiffness blank-holder for applications in high strength steel and laser welding parts

This study presents experimental and numerical results of a development prototype tool that includes blank-holder plates of variable stiffness. The application is analyzed for high-strength steel parts and tailor welded blanks manufactured from dissimilar steel grades using laser welding. A numerical model was constructed within the Ansys software platform incorporating appropriate material constitutive models parameters for high-strength Dual-Phase steels. The obtained results show a positive control of springback geometries. Experimental tests were performed on the relevant geometries. The presented numerical and experimental results constitute a validation of a variable-stiffness blank-holder approach for this particular case study.The funding support from Project I&DT AdvancedTOOLING CENTRO-01-0247- FEDER-011399 is acknowledged