My research area is theoretical cosmology and the large-scale structure of the universe. I'm interested in nature of the universe, and understanding how the structure of the universe have formed throughout the history of the universe. The universe is governed by linear, quasi-nonlinear, and fully nonlinear dynamics, depending on scales of interest. Linear and quasi-nonlinear dynamics are accessible by analytical methods and fully nonlinear dynamics are appropriately depicted by numerical simulations, and empirical models are also useful. While analytic approaches are my primary interest, I analyze data from numerical simulations as well as data from actual observations, when necessary. Among others, the galaxy redshift survey is one of the best way to characterize structures of the universe. Statistics of the large-scale structure shed lights on the global history of the universe. I've developed many analytical methods to characterize the large-scale structure and also exploited novel statistical methods to analyze the galaxy redshift surveys.