AR_final file_2018-19

formulations are different, these two emergent per- spectives of gravity describes a universe, which be- haves as an ordinary macroscopic system. In par- ticular, an asymptotically de Sitter universe that proceeds to satisfy holographic equi partition con- dition | E | = 1 2 N surf k B T also evolves to obey Ver- linde’s relation Mc 2 = 1 2 Nk B T . Our results pro- vide a thermodynamic basis to the emergent grav- ity paradigm. This work has been done in collabo- ration with P. B. Krishna. Irom Ablu Meitei Quantum gravity effects on scalar particle tunneling from rotating BTZ black hole Tunneling of scalar particles across the event hori- zon of rotating BTZ black hole is investigated us- ing the Generalized Uncertainty Principle to study the corrected Hawking temperature and entropy in the presence of quantum gravity effects. We have determined explicitly the various correction terms in the entropy of rotating BTZ black hole including the logarithmic term of the Bekenstein- Hawking entropy ( S BH ), the inverse term of S BH and terms with inverse powers of S BH , in terms of properties of the black hole and the emitted par- ticles - mass, energy and angular momentum. In the presence of quantum gravity effects, for the emission of scalar particles, the Hawking radiation and thermodynamics of rotating BTZ black hole are observed to be related to the metric element, hence, to the curvature of spacetime. This work has been done in collaboration with T.Ibungochouba Singh, S.Gayatri Devi, N.Premeshwari Devi, and K.Yugindro Singh. Quantization of horizon area of Kerr-Newman-de Sitter black hole Using the adiabatic invariant action, and apply- ing the Bohr-Sommerfeld quantization rule, and first law of black hole thermodynamics, a study of quantization of entropy and horizon area of Kerr- Newman-de Sitter black hole is carried out. The same entropy spectrum is obtained in two different coordinate systems. It is also observed that the spacing of the entropy spectrum is independent of the black hole parameters. Also, the corresponding quantum of horizon area is in agreement with the results of Bekenstein. This work has been done in collaboration with Y. Kenedy Meitei, and T. Ibun- gochouba Singh. Bivudutta Mishra Dynamics of anisotropic dark energy universe em- bedded in one-directional magnetized fluid In this work, we have constructed an anisotropic dark energy cosmological model in a two fluid situa- tions such as the usual dark energy and the magne- tized fluid. We have assumed that the dark energy pressure to be anisotropic in different spatial direc- tions. In order to develop the mathematical for- malism of the model, we have considered the scale factor, as hybrid scale factor which is a combina- tion of both power law and exponential volumetric expansion law. The physical parameters are de- rived, analysed and found to be in agreement with the observational limits. This work has been done in collaboration with Pratik P. Ray, and S. K. Tri- pathy. Anisotropic cosmological reconstruction in f ( R, T ) gravity Anisotropic cosmological models are constructed in f ( R, T ) gravity theory to investigate the dynamics of universe concerning the late time cosmic acceler- ation. Using a more general and simple approach, the effect of the coupling constant and anisotropy on the cosmic dynamics have been investigated. In this study, it is found that cosmic anisotropy affects substantially the cosmic dynamics. This work has been done in collaboration with Sankarsan Tarai, and S. K. Tripathy. Sourav Mitra First study of reionization in the Planck 2015 nor- malized closed in Λ CDM inflation model We study reionization in two non-flat ΛCDM infla- tion models that best fit the Planck 2015 cosmic microwave background anisotropy observations, ig- noring or in conjunction with baryon acoustic os- cillation distance measurements. We implement a principal component analysis (PCA) to estimate the uncertainties in the reionization history from a joint quasar-CMB dataset. A thorough Markov Chain Monte Carlo analysis is done over the pa- rameter space of PCA modes for both non-flat ΛCDM inflation models as well as the original Planck 2016 tilted, spatially-flat ΛCDM inflation model. Although both flat and non-flat models can closely match the low-redshift ( z . 6) obser- vations, we notice a possible tension between high- ( 200 )