Non-linear realization of gauge symmetries in open gravitational EFTs

Characterize the non-linear realization of gauge symmetries, including the deformed advanced symmetry structure, in the open effective field theory of gravity built within the Schwinger–Keldysh framework and determine its implications for operator construction and consistency.

Background

In the open EFT approach, doubled fields and dissipative dynamics modify how diffeomorphism symmetries are realized, especially beyond linear order.

Although linear-order symmetry implications are understood, the authors emphasize that the non-linear realization of gauge symmetries in open gravity remains to be clarified, which is needed for robustly extending the framework and constraining allowed operators.

References

A few foundational aspects are still under investigation, including a prescription to count propagating degrees of freedom, additional consistency conditions on dissipative operators , and the non-linear realization of gauge symmetries . In this work, we set aside these interesting open questions and instead concentrate on a minimal model, whose internal consistency has been established in .

— Phenomenology of an Open Effective Field Theory of Dark Energy  (2603.12321 - Salcedo et al., 12 Mar 2026) in Open Effective Field Theories paragraph (main text)