29th Annual Report (2016-17)

204 Areas of Research Research Work List of Publications · · · · · · · Magnetogenesis in early universe Magnetic fields in galactic systems and inter-galactic region Cosmic reionization and 21 cm cosmology High energy physics in higher dimensional cosmology While there are theories for the primordial generation of magnetic fields, no theory exist which is free from problems. One of the problems that plagues the theories of inflationary generation of magnetic fields is the strong coupling. The issue deals with the fact that in almost all such magnetogenesis models, the effective electric charge is very large in the beginning of inflation.At IRC, we have addressed this issue, and have been studying scenarios where this problem can be avoided. Using the technique of fractal dimension, the nature of neutral Hydrogen clouds at the epoch of reionization has been studied. Fractal characterization of inside-out model is very different from the outside-in model. This can be a probe to see the details of how reionization proceeded. Cosmic curvature of the Universe has been constrained using the ages of galaxies and gravitational lensing. It has been shown that the flat universe is consistent at a 3ó level. But the best fit line shows deviation from the flat universe prediction. Akshay Rana, Deepak Jain, Shobhit Mahajan and Amitabha Mukherjee (2016), Revisiting the distance duality relation using the non-parametric regressionmethod , JCAP, 7, 26. Bidisha Bandyopadhyay, Tirthankar Roy Choudhury and T. R. Seshadri (2017) Studying neutral Hydrogen structures during the epoch of reionization using fractal dimensions , MNRAS, 466(2), 2302. Akshay Rana, Deepak Jain, Shobhit Mahajan and Amitabha Mukherjee (2017) Constraining cosmic curvature by using age of galaxies and gravitational lenses , JCAP, 3, 28. Nisha Rani, Deepak Jain, Shobhit Mahajan, Amitabha Mukherjee and Marek Biesiada (2017) Revisiting dark energy models using differential ages of galaxies , JCAP, 3, 5. Department of Physics and Astrophysics, University of Delhi Coordinator: T.R. Seshadri, and Joint Coordinator: Harinder Pal Singh 29 th ANNUAL RE PORT 2016-17 IUCAA RESOURCE CENTRES