Published January 2023 | Published
Journal Article

All identically conserved gravitational tensors are metric variations of invariant actions

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon Brandeis University

Abstract

I prove an old unsolved conjecture, the hard – necessary – part of its obvious sufficiency, namely that all identically conserved symmetric 2-tensors are necessarily metric variations of invariant actions, thus sparing the world more alternative gravity theories. The proof is reasonably simple, if perhaps a "physicist's".

Copyright and License

© 2022 Elsevier Inc. All rights reserved.

Acknowledgement

I thank my old collaborator, Y. Pang for useful correspondence, a referee for insisting on better details, and J. Franklin for tech help.

Funding

This work was supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics , Award Number de-sc0011632.

Additional details

Created:
September 17, 2025
Modified:
September 17, 2025