Inequivalence of mimetic gravity with models of loop quantum gravity

Abstract

Certain versions of mimetic gravity have recently been claimed to present potential covariant theories of canonically modified spherically symmetric gravity, motivated by ingredients from loop quantum gravity. If such an equivalence were to hold, it would demonstrate general covariance of a large class of models considered in loop quantum gravity. However, the relationship with mimetic gravity as presented so far is incomplete because it has been proposed only in preferred space-time slicings of uniform scalar fields. Here, several independent arguments are used to show that neither an equivalence nor a covariance claim are correct for models of loop quantum gravity. The framework of emergent modified gravity is found to present a broad setting in which such questions can be analyzed efficiently. As an additional result, the discussion sheds light on the co-existence of different and mutually inequivalent approaches to an implementation of the gravitational dynamics within loop quantum gravity.

16 pages

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Cited by in corpus (6)

• Black Holes and Covariance in Effective Quantum Gravity
• Absorption, Scattering, Geodesics, Shadows and Lensing Phenomena of Black Holes in Effective Quantum Gravity
• Gravitational lensing effect of black holes in effective quantum gravity
• Black holes and covariance in effective quantum gravity: A solution without Cauchy horizons
• Influence of Quantum Correction on Kerr Black Hole in Effective Loop Quantum Gravity via Shadows and EHT Results
• Lessons for loop quantum gravity from emergent modified gravity