https://arxiv.org/abs/gr-qc/9903047
[gr-qc/9903047] On the General Covariance in the Bohmian Quantum Gravity
Abstract page for arXiv paper gr-qc/9903047: On the General Covariance in the Bohmian Quantum Gravity
on thegeneral covariancegrqc
https://pmc.ncbi.nlm.nih.gov/articles/PMC17695/
General covariance and harmonic maps - PMC
The principle of general covariance is used to derive the conditions for a map to be harmonic. Modification to the harmonic map equations due to the presence...
general covarianceharmonic mapspmc