Speaker
Description
Scalar-tensor theory not only serves as one of the most important tools for constructing models in cosmology and gravitational wave research but also offers a broad playground for exploring modified gravity. In this talk, I will first review the development of scalar-tensor theory over the past two decades. In particular, I will present our efforts to utilize spatially covariant gravity as an effective and efficient framework for developing higher-derivative scalar-tensor theories without introducing ghost degrees of freedom. I will then discuss our recent results in constructing two new classes of scalar-tensor theories based on this approach: one featuring parity-violating effects and the other incorporating multiple scalar fields. These developments expand the scope of scalar-tensor theories and open new avenues for theoretical exploration.
