My research lies at the intersection of theoretical particle physics and cosmology, with special focus on the following topics:

• The origin of matter-antimatter asymmetry
• The origin of dark matter
• Strong CP problem
• The origin of neutrino mass and neutrino self interaction.

Both bottom-up and upside-down approaches are interesting to me. Basically, they can be categorized into the following.

Bottom-up approach

I’m specifically interested in new and fancy experimental probes of new physics. This currently includes:

• Probing thermal-relic dark matter with various well-motivated simplified model.
• Probing various models with neutrino self-interaction in neutrino experiments/observations.
• Thermal history of simplified models for dark matter and neutrino.
• Controversies in the calculation details/probing methods in various cases, including electroweak phase transition/thermal freeze-in and freeze-out/gravitational waves.

Upside-down approach

I’m interested in a series of interesting models. Models that could explain a few unsolved puzzles simultaneously are appealing to me.

Specifically, I pay attention to models that contains the following elements:

• Solving the strong CP problem.
• Electroweak (-like) baryogenesis.
• Other ways of baryogenesis.
• Explain neutrino masses.
• Contains a good dark matter candidate.

I work to extend those models and investigate their imprints in the universe and experiments. These include but not limited to:

• Parity-symmetric model.
• Rotating axion/scalar field.
• Twin/Mirror sector models.

Projects

Here is a list of the projects that I’ve been working on/have finished. The introduction of these projects are really introductory, and the readers are just required to have some basic knowledge of quantum field theory. If you are an expert and want to have a quick understanding of what I’m working on, skip the introduction section.

Neutrino mass and self-interaction

Neutrino is a massless, feebly-interacting particle in SM. However, it is known that neutrino should be massive. New physics is guaranteed to exist in the neutrino sector. Basic question naturally raises regarding neutrino physics. What is the source of neutrino mass? Can neutrino have self-interactions?

Axion rotation

I work on experimental and cosmological searches of dark sector mediators.

Search for dark sector mediator

I work on experimental and cosmological searches of dark sector mediators.

Electroweak (-like) baryogenesis

Electroweak (-like) phase transition is expected to happen in the early universe, given the well-known spontaneous gauge symmetry breaking. This phase transition, if of first order, can provide the necessary out-of-equilbrium condition for baryogenesis. Such a phase transition can happen for the SM electroweak symmetry breaking, or any other similar symmetry breaking in BSM gauge group extensions. This project investigates possibilities to achieve electroweak (-like) baryogenesis in different models.

Parity-symmetric model

A type of models that can solve the strong CP problem, with large potential to explain the origin of matter-antimatter asymmetry and provide dark matter candidate.