Abstract Details

Name: Mussadiq Hussain Qureshi
Affiliation: University of Kashmir
Conference ID: ASI2017_421
Title : Punctuated Inflation and low-l power supression in CMB
Authors and Co-Authors : Mussadiq H. Qureshi Affiliation:Kashmir University Asif Iqbal Affiliation:Kashmir University Manzoor A. Malik Affiliation: Kashmir University Tarun Souradeep Affiliation: IUCAA
Abstract Type : Poster
Abstract Category : General Relativity and Cosmology
Abstract : Anisotropies in Cosmic Microwave Background is one of the robust and informative tools in cosmology. Measurements of CMB Anisotropies by COBE, WMAP9 and PLANCK are in striking agreement with $\Lambda$CDM cosmology and their results are consistent with an adiabatic and nearly scale invariant spectrum of primordial fluctuations as predicted by simple inflationary models. However, there are certain anomalies in CMB data which could have far reaching consequences. One of these anomalies is low CMB power at large scales with PLANCK confirmation of an anomalously low value of CMB temperature fluctuations upto multi-pole $l\leq 40$. Here we will try to explain this feature by investigating case of punctuated inflationary (PI) scenario (inspired by Minimal Super-symmetric Standard Models) wherein suppression of curvature perturbation power at large scales is produced by sand-witching a period of fast-roll phase between two stages of slow-roll phase. We then apply Markov Chain Monte Carlo analysis to determine posterior distribution and best fit values of model parameters using WMAP9 and PLANCK data. We also show that WMAP9 and PLANCK results are consistent with each other, with PLANCK data providing much tighter constraints for punctuated inflation parameters. Also punctuated inflation provides better fit in CMB data compared to simple power law model (PI) which is evident from the fact that $\Delta\chi^2 \approx 4$ for WMAP9 and $\Delta\chi^2 \approx 17$ for WMAP9+PLANCK. Further, we use Akakie Information Criteria (AIC) for model comparison which showed that for WMAP9+PLANCK data, PI model is preferred over PL model while as for WMAP9 data set only, both models are equally favorable.