REVIEW 5 cited by
A simple parity violating model in the symmetric teleparallel gravity and its cosmological perturbations
Not yet reviewed by Pith; the record is open.
This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.
SPECIMEN: schema-true, not a live event
T0 review · schema-true
One-sentence machine reading of the paper's core claim.
pith:XXXXXXXX · record.json · timestamp
read the original abstract
The parity violating gravity models based on the symmetric teleparallel gravity have been considered in the literature, but their applications in cosmology and especially the modifications to cosmological perturbations have not been fully explored. In this paper we consider such a simple model which modifies general relativity by a parity non-conserved coupling, within the framework of the symmetric teleparallel gravity. We study in detail its cosmological applications and focus on its cosmological perturbation theory. Besides the already known parity violation in the tensor perturbations, we find that the vector perturbations in this model are promoted to be dynamical degrees of freedom, and the left- and right-handed vector modes propagate with different velocities. More importantly, we find that one of the vector modes is a ghost at high momentum scales, which will give rise to the problem of vacuum instability in the quantum theory of cosmological perturbations.
Forward citations
Cited by 5 Pith papers
-
Parity-violating spatially covariant gravity at total derivative order $d=5$
At total derivative order five, parity-violating spatially covariant gravity has exactly 59 independent monomials, and their tensor-perturbation response is controlled by four coefficient combinations producing helici...
-
Circularly polarized gravitational waves from parity-violating scalar-tensor theory
In the "Qi-Xiu" parity-violating scalar-tensor theory, the L3 and L4 interactions leave linear gravitational-wave propagation GR-like but still generate circularly polarized scalar-induced gravitational waves.
-
Degrees of freedom of a quadratic scalar-nonmetricity theory
In quadratic scalar-nonmetricity gravity, Hamiltonian analysis shows 10, 8, and 8 degrees of freedom for cases II, V, and VI, while linear cosmological perturbation theory sees only 10, 6, and 5, indicating hidden str...
-
Fixed-Time Voltage Regulation for Boost Converters via Unit-Safe Saturating Functions
A fixed-time feedback controller for boost converters uses a new class of saturating functions, observers, and adaptive gains to regulate output voltage within a bounded settling time under unknown load resistance.
-
Constraining parity and Lorentz violations in gravity with future ground- and space-based gravitational wave detectors
Future gravitational wave detectors could tighten constraints on parity- and Lorentz-violating energy scales by one to three orders of magnitude, with space-based detectors winning for certain frequency dependencies.
Discussion (0). Continue with ORCID to comment.