In particular, I'm interested in a possible way of extracting some basic, fundamental aspects of physics from observations: 

1. Gravitational Positivity bounds

I'm trying to understand how the information of UV complete quantum gravity is imprinted on its low-energy effective theory, in light of S-matrix positivity bounds in the presence of gravity. I have been working on its formulation as well as its applications to phenemology. 

Formulation of gravitatational positivity bounds is challenging, and still in progress in the literatures. We proposed a formulation based on the gravitational Regge behavior and the Finite Energy Sum Rules (arXiv:[hep-th]2007.15009, arXiv:[hep-th]2212.08001). Another formulation based on the sum rule in finite t has been also proposed in the literatures, which particularly works well in D>4 spacetime dimensions. All of the results suggest that positivity violation is allowed in the presence of gravity: we identified the high-energy processes which concretely explain this violation in arXiv:[hep-th]2406.07606. 

Complementary to the formulation study,  I've been also investigating phenomenological implications for the Standard Model(arXiv:[hep-th]2104.09682), scalar potential(arXiv:[hep-th]2105.01436), and the dark sector physics(arXiv:[hep-th]2205.12835, arXiv:[hep-th]2305.10058). These works could connect low-energy physics with UV quantum gravity. However, I should emphasize that the current knowledge of properties of gravitational UV amplitude is not enough to obtain interesting Swampland conditions on EFTs- this point is clarified in our recent work arXiv:[hep-th]2406.07606 quantitatively.  Futher studies of UV amplitude in a concrete UV complete scenario must be crucial.


2. Infrared secular effects, Stochastic inflation

I'm working on the infrared secular effects during inflation, and some related topics such as stochastic inflation.

3. Detection of gravitons 

One of the final goal is to find a realistic setup to test if the quantized gravitons really exist.