Stealth solutions in mimetic gravity decouple from background dynamics on the lambda=0 branch but impose an infinite hierarchy of constraints on perturbations, rendering the screening limit non-uniform and pathological.
Vainshtein mechanism after GW170817
6 Pith papers cite this work. Polarity classification is still indexing.
6
Pith papers citing it
abstract
The almost simultaneous detection of gravitational waves and a short gamma-ray burst from a neutron star merger has put a tight constraint on the difference between the speed of gravity and light. In the four-dimensional scalar-tensor theory with second order equations of motion, the Horndeski theory, this translates into a significant reduction of the viable parameter space of the theory. Recently, extensions of Horndeski theory, which are free from Ostrogradsky ghosts despite the presence of higher order derivatives in the equations of motion, have been identified and classified exploiting the degeneracy criterium. In these new theories, the fifth force mediated by the scalar field must be suppressed in order to evade the stringent Solar System constraints. We study the Vainshtein mechanism in the most general degenerate higher order scalar-tensor theory in which light and gravity propagate at the same speed. We find that the Vainshtein mechanism generally works outside a matter source but it is broken inside matter, similarly to beyond Horndeski theories. This leaves interesting possibilities to test these theories that are compatible with gravitational wave observations using astrophysical objects.
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A metric-affine version of quadratic DHOST theories is derived and reduced to a one-function family that satisfies degeneracy conditions and light-speed gravitational wave propagation.
A master screening equation is derived for luminal Horndeski gravity that recovers Vainshtein and Chameleon mechanisms and introduces Phaedrus screening with screening radius scaling linearly with source mass.
BlackHawk v3.0 adds Hawking temperatures and greybody factors for multiple regular black hole metrics to an existing public code via numerical routines.
In DHOST theories consistent with GW observations, deviations from GR suppress high-redshift galaxy cluster abundance relative to ΛCDM when using spherical collapse and analytic mass functions matched to eROSITA data.
Thesis summarizing an upper limit of 0.12 eV on the neutrino mass sum, bias calibration via CMB lensing cross-correlations, and tighter limits plus stronger normal-ordering preference in non-phantom dynamical dark energy models.
citing papers explorer
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Fragility of stealth solutions in mimetic gravity
Stealth solutions in mimetic gravity decouple from background dynamics on the lambda=0 branch but impose an infinite hierarchy of constraints on perturbations, rendering the screening limit non-uniform and pathological.
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Degenerate higher-order scalar-tensor theories in metric-affine gravity
A metric-affine version of quadratic DHOST theories is derived and reduced to a one-function family that satisfies degeneracy conditions and light-speed gravitational wave propagation.
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A Master Equation for Screening in Luminal Horndeski Gravity
A master screening equation is derived for luminal Horndeski gravity that recovers Vainshtein and Chameleon mechanisms and introduces Phaedrus screening with screening radius scaling linearly with source mass.
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$\tt BlackHawk$ $\tt v3.0$: Hawking Radiation from Regular Black Holes
BlackHawk v3.0 adds Hawking temperatures and greybody factors for multiple regular black hole metrics to an existing public code via numerical routines.