3 papers
gr-qc2026
Parity-violating spatially covariant gravity at total derivative order
Jin-Jian Song, Xian Gao
We extend the polynomial construction of parity-violating spatially covariant gravity (SCG) to total derivative order , where counts the tota…
gr-qc2026
Spatially covariant gravity with two degrees of freedom: A perturbative analysis up to cubic order
Yang Yu, Yu-Min Hu, Xian Gao
There has been considerable interest in constructing modified gravity theories that propagate only two degrees of freedom (DOFs), corresponding to the tensorial gravitational waves…
gr-qc2024
Interacting hypersurfaces and multiple scalar-tensor theories
Yang Yu, Zheng Chen, Yu-Min Hu +1
We propose a novel method to construct ghost-free multiple scalar-tensor theories. The key idea is to use the geometric quantities of hypersurfaces defined by the scalar fields, ra…