Biennial Report 2005-2007 - Saha Institute of Nuclear Physics

6 Biennial Report 2005-071.2.1.13 Counting black hole microscopic states in loop quantum gravityCounting of microscopic states of black holes is performed within the framework of loop quantumgravity. This is the first calculation of the pure horizon states using statistical methods, whichreveals the possibility of additional states missed in the earlier calculations, leading to an increaseof entropy. Also for the first time a microcanonical temperature is introduced within the framework.Amit Ghosh, Parthasarathi MitraTheo1.2.1.14 Dark Energy Reconstruction from SNIa and GRB data and their comparisonDistance measurement of Supernova Ia (SNIa, standard candle) suggest that the universe is acceleratingand this acceleration is supported by a mysterious energy or Dark Energy that constitutes73% of the total content of the universe. The Dark Energy parameters are and the subsequentreconstruction uses the observational data (such as from SNIa) like the luminosity distance or distancemodulii, coordinate distance etc. While the supernova Ia are more accurate standard candlesin respect of such measurements, the data obtained from SNIa span a smaller range of redshift z(mostly z ≤ 1). While the observations from GRB span wider range of redshift (∼ 6). Thus GRBmeasurements open up the possibility of more detailed study of the nature of variation of DarkEnergy. In the present work a comparative study is made for the Dark Energy evolution both fromSNIa and GRB data.Debasish MajumdarINO1.2.2 Phenomenology1.2.2.1 Possible violation of the spin-statistics relation for neutrinos: detectingthrough future galactic supernovaThe detection of neutrinos from a future galactic type II supernova event in a water Cerenkovdetector like Super-Kamiokande is used to constrain the possible violation of spin-statistics relationfor neutrinos resulting in their obeying a mixed statistics instead of Fermi-Dirac.Sandhya Choubey†, Kamales KarTheo1.2.2.2 A GEANT-based study of atmospheric neutrino oscillation parameters atINOThe dependence of the allowed space of the atmospheric neutrino oscillation parameters on thetime of exposure for a magnetized Iron CALorimeter (ICAL) detector at the India-based NeutrinoObservatory (INO) has been studied. We have performed a Monte Carlo simulation for a 50kTonICAL detector generating events by the neutrino generator NUANCE and simulating the detectorresponse by GEANT. A chi-square analysis for the ratio of the up-going and down-going neutrinos