Biennial Report 2005-2007 - Saha Institute of Nuclear Physics

128 Biennial Report 2005-07is an oscillatory function of both d and V 0 . We also show that the periodicity and amplitude ofsuch oscillations deviate from their universal values in the thin barrier limit as obtained in earlierwork [Phys. Rev. Lett. 97, 217001 (2006)] and become a function of the applied voltage V 0 . Ourresults reproduces the earlier results on tunneling conductance of such junctions in the thin [Phys.Rev. Lett. 97, 217001 (2006)] and zero [Phys. Rev. Lett. 97, 067007 (2006)] barrier limits asspecial limiting cases. We discuss experimental relevance of our results.Subhro Bhattacharjee†, Moitri Maiti, K SenguptaTCMP4.2.1.9 Non-perturbative renormalization-group approach to zero-temperature BosesystemsDetails of the work: We study the non-perturbative renormalization group technique to studyinteracting bosons at zero tempoerature. Our analysis reveals the instability of the Bogoliubovfixed point for d1.Nicolas Dupuis†, K SenguptaTCMP4.2.2 Studies in Statistical Mechanics4.2.2.1 Kolmogorov dispersion for turbulence in porous media: A conjectureWe will utilise the self-avoiding walk (SAW) mapping of the vortex line conformations in turbulenceto get the Kolmogorov scale dependence of energy dispersion from SAW statistics, and the knowledgeof the disordered fractal geometries on the SAW statistics. These will give us the Kolmogorovenergy dispersion exponent value for turbulence in porous media in terms of the size exponentfor polymers in the same. We argue that the exponent value will be somewhat less than 5/3 forturbulence in porous media.BK ChakrabartiTCMP4.2.2.2 Economic Inequality: Is it Natural?Mounting evidences are being gathered suggesting that income and wealth distribution in variouscountries or societies follow a robust pattern, close to the Gibbs distribution of energy in an idealgas in equilibrium, but also deviating significantly for high income groups. Application of physicsmodels seem to provide illuminating ideas and understanding, complimenting the observations.A Chatterjee, S Sinha, BK ChakrabartiTCMP