Theories of The Early Universe in The Era of Precision Cosmology

Cosmology is the history book with chronological details of the universe-our home. The most vague chapter in that book is the first chapter where the details of the first few moments of the nascent universe should be given in details. In this talk, I will try to explore some of the theoretical efforts to understand the early universe like landscape multiverse and some of the inflationary models. The effort will be to understand these theories in the light of the recent observations. It is undeniable fact that we live in the era of Precision Cosmology. Thus, constraining these theories has become very important and on that note I will try to explain how statistical analysis has become an integral part of the theoretical cosmology. I will also try to touch some of the anomalies present in the recent observations which needs proper theoretical explanations. (Based on arXiv:1504.0691, arXiv:1504.01214, arXiv:1607.06858 and arXiv:1611.05123)