Pith

open record

sign in

arxiv: 2204.02032 · v2 · pith:3CJPBBUP · submitted 2022-04-05 · gr-qc · hep-th

Built-in scordatura in U-DHOST

Antonio De Felice , Shinji Mukohyama , Kazufumi Takahashi This is my paper

Reviewed by Pith T0 review T1 audit T2 compute T3 formal T4 kernel pith:3CJPBBUPrecord.jsonopen to challenge →

classification gr-qc hep-th
keywords theoriessolutionsu-dhostmodebuilt-incouplingdegenerategeneral
0
0 comments X
read the original abstract

Modified gravity theories can accommodate exact solutions, for which the metric has the same form as the one in general relativity, i.e., stealth solutions. One problem with these stealth solutions is that perturbations around them exhibit strong coupling when the solutions are realized in degenerate higher-order scalar-tensor theories. We show that the strong coupling problem can be circumvented in the framework of the so-called U-DHOST theories, in which the degeneracy is partially broken in such a way that higher-derivative terms are degenerate only in the unitary gauge. In this sense, the scordatura effect is built-in in U-DHOST theories in general. There is an apparent Ostrogradsky mode in U-DHOST theories, but it does not propagate as it satisfies a three-dimensional elliptic differential equation on a spacelike hypersurface. We also clarify how this nonpropagating mode, i.e., the "shadowy" mode shows up at the nonlinear level.

This paper has not been read by Pith yet.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 4 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Covariant scalar-tensor theories beyond second derivatives

    hep-th 2026-04 conditional novelty 8.0

    A new covariant foliation-based construction of scalar-tensor theories up to four derivatives of the scalar field that extends DHOST and U-DHOST without unitary gauge and propagates three degrees of freedom.

  2. Testing Dark Energy with Black Hole Ringdown

    gr-qc 2026-03 unverdicted novelty 7.0

    Dynamical dark energy imprints O(1) shifts on black hole quasi-normal modes via cosmological hair, enabling constraints at 10^{-2} (LVK) to 10^{-4} (LISA) precision using the cubic Galileon as example.

  3. Stable black hole solutions with cosmological hair

    gr-qc 2026-03 unverdicted novelty 7.0

    Stable black hole solutions with cosmological scalar hair are explicitly derived in the cubic Galileon theory, recovering cosmological behavior at large distances and regular short-range dynamics.

  4. Inverting no-hair theorems: How requiring General Relativity solutions restricts scalar-tensor theories

    gr-qc 2025-03 accept novelty 7.0

    Requiring stealth Schwarzschild and de Sitter solutions in quadratic/cubic scalar-tensor theories eliminates odd-parity deviations from GR when all solutions are required, while allowing some deviations and non-trivia...