My research interest lies in understanding particle physics not explained by the Standard Model (SM). I use both phenomenological and formal approaches. On the phenomenological side, I have been focused on two directions. One is studying how to use effective field theories (EFTs) more efficiently, especially the SM EFT. This provides a greatly simplified way of investigating the consequences of high-energy models on low-energy observables. The other is to study the implications of the LHC data. By performing collider simulations, I impose bounds from various LHC searches on phenomenological or simplified models, and obtain insights for model building. On the formal side, I am interested in deriving consistency conditions on sensible theories from basic principles, such as causality, unitarity, crossing relations, etc. This philosophy has been quite successful in the area of CFT, especially with the conformal bootstrap equations, but there are a lot more to be done. I have also worked on the naturalness problem of the Higgs, neutrino physics, and the origin of baryon asymmetry in the universe.