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Extended mimetic gravity: Hamiltonian analysis and gradient instabilities

2 Pith papers cite this work. Polarity classification is still indexing.

2 Pith papers citing it
abstract

We propose a novel class of degenerate higher-order scalar-tensor theories as an extension of mimetic gravity. By performing a noninvertible conformal transformation on "seed" scalar-tensor theories which may be nondegenerate, we can generate a large class of theories with at most three physical degrees of freedom. We identify a general seed theory for which this is possible. Cosmological perturbations in these extended mimetic theories are also studied. It is shown that either of tensor or scalar perturbations is plagued with gradient instabilities, except for a special case where the scalar perturbations are presumably strongly coupled, or otherwise there appear ghost instabilities.

citation-role summary

background 1

citation-polarity summary

fields

gr-qc 2

years

2026 1 2025 1

verdicts

UNVERDICTED 2

roles

background 1

polarities

background 1

representative citing papers

Imperfect dark matter with higher derivatives

gr-qc · 2025-10-27 · unverdicted · novelty 6.0

Higher-derivative extension of dark matter yields an imperfect fluid that matches pressureless dust on homogeneous backgrounds but generates acceleration and vorticity to avoid caustic singularities in inhomogeneous cosmologies.

citing papers explorer

Showing 2 of 2 citing papers.

  • Gravitational wave constraints on the Paneitz operator gr-qc · 2026-04-30 · unverdicted · none · ref 41

    The Paneitz operator in 4D belongs to extended mimetic gravity and is constrained by gravitational wave propagation speed.

  • Imperfect dark matter with higher derivatives gr-qc · 2025-10-27 · unverdicted · none · ref 36 · internal anchor

    Higher-derivative extension of dark matter yields an imperfect fluid that matches pressureless dust on homogeneous backgrounds but generates acceleration and vorticity to avoid caustic singularities in inhomogeneous cosmologies.