Recently, the research paper "Covariant Dynamics from Static Spherically Symmetric Geometries", jointly completed by Zhang Cong and Prof. Cao Zhoujian from the Center for Relativity and Gravitation, School of Physics and Astronomy, Beijing Normal University,  has been published in Physical Review Letters (PRL). The achievement systematically answers a long-unresolved theoretical question: How can one construct a self-consistent, covariant field-theoretic origin for a novel static, spherically symmetric spacetime beyond general relativity, such that the underlying theory admits the spacetime as its unique vacuum solution?

Abstrct:
This work reveals a fundamental link between general covariance and Birkhoff’s theorem. We extend Birkhoff’s theorem from general relativity to a broad class of generally covariant gravity theories formulated in the Hamiltonian framework. Conversely, we show that each one-parameter family of static, spherically symmetric spacetimes determines a class of covariant theories, each of which has that family of spacetimes as its entire vacuum solution space. Our systematic and model-independent framework applies to a wide range of spacetimes, including observationally inferred, quantum-gravity-inspired, and regular black holes. It provides a universal tool for probing their dynamical origins and enables the reconstruction of the underlying covariant theories from observational data, including gravitational-wave and black-hole-shadow measurements.

Reference: https://journals.aps.org/prl/abstract/10.1103/6sws-hfj7