12 papers
Reference Frames and Gravitational-Wave Polarizations: Symmetry Classification and Preferred-Frame Phenomenology
Jie Zhu, Hao Li
Gravitational wave (GW) polarizations are traditionally classified in a fixed frame ( classification), which does not account for how polarization patterns change under Loren…
Revisit Static Aether: Exact Vacuum Solution in Einstein-Aether Theory and Its Analytic Extension
Jie Zhu, Hao Li
We obtain an exact analytical vacuum solution of Einstein-Aether theory with a strictly static aether configuration and investigate its maximal extension. The solution depends only…
Dynamic Aspects of Bumblebee Gravity: Post-Newtonian Approach
Jie Zhu, Hao Li
In this work, we investigate the dynamic aspects of Bumblebee gravity via the parameterized post-Newtonian method. We find that the PPN framework is self-consistent up to 1.5PN ord…
On the Consistency of Covariant Light-Speed Variation in Doubly Special Relativity
Hao Li, Jie Zhu
Doubly special relativity (DSR) introduces an observer-independent energy scale while preserving a deformed relativistic notion of covariance. In many realizations, this leads to a…
Parameterized Post-Newtonian Analysis of Quadratic Gravity and Solar System Constraints
Jie Zhu, Hao Li
This work systematically investigates the post-Newtonian behavior of general quadratic gravity in the weak-field regime. By extending the Einstein-Hilbert action to include quadrat…
Hamiltonian Constraints on Spontaneous Lorentz Symmetry Breaking in the Bumblebee Model
Jie Zhu, Hao Li, Zhi Xiao
This study demonstrates that the common practice of determining spontaneous Lorentz violation via the minimum of a Lagrangian potential is generally incorrect. By analyzing the Ham…