2 papers
gr-qc2026
Bi-scalar-tensor theory: a spatially covariant gravity approach
Jia-Jun Chen, Xian Gao, Tsutomu Kobayashi
We propose a novel method for constructing ghost-free multi-field higher-derivative scalar-tensor theories. The idea is to start from spatially covariant gravity and couple it to a…
gr-qc2025
Degrees of freedom of a quadratic scalar-nonmetricity theory
Jia-Jun Chen, Zheng Chen, Xian Gao
We study the number of degrees of freedom (DOFs) in quadratic scalar-nonmetricity (QSN) theory, whose Lagrangian is the linear combination of five quadratic nonmetricity invariants…