REVIEW 4 cited by
Unitarity through PT symmetry in Quantum Quadratic Gravity
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
Theories described by non-Hermitian Hamiltonians are known to possess strictly positive energy eigenvalues and exhibit unitary time evolution if the Hamiltonian is symmetric under discrete parity and time (PT) transformation. In this work, we demonstrate how quantum quadratic gravity, a theory that generally violates unitarity when viewed as a Hermitian quantum field theory, can be complex-deformed into such a PT-symmetric theory with an action that consists of a ghost-less Hermitian free part and non-Hermitian interactions. Paying special attention to the gauge symmetry present in the theory, we quantize in the covariant operator formalism after suggesting how the framework might be extended to the pseudo-Hermitian picture. We find compelling evidence that the resulting quantum theory possesses a unitary inner product and a sensible interpretation of quantum probability, thus avoiding the ghost problem present in the Hermitian formulation of quadratic gravity.
Forward citations
Cited by 4 Pith papers
-
Primordial Gravitational Waves in Quadratic Gravity
In quadratic gravity, the inflationary tensor power spectrum is suppressed by (1 + 2H_*^2/m_gh^2)^{-1}, which restores the standard consistency relation r = -8n_t.
-
Remarks on ghost resonances
For a ghost field above the multiparticle threshold, the dressed propagator carries a complex conjugate pole pair in the first Riemann sheet, and the paper derives spectral representations for both sheets while flaggi...
-
Closed timelike curves in PT-symmetric wormholes
A bimetric PT-symmetric wormhole model is claimed to enable one-way traversal and, when coupled in pairs, to generate closed timelike curves consistent with Novikov's self-consistency principle.
-
Oscillators with imaginary coupling: spectral functions in quantum mechanics and quantum field theory
A pair of oscillators or scalar fields with imaginary coupling has real energy levels under a modified inner product, and non-positive spectral functions are linked to non-observable operators.
Discussion (0). Continue with ORCID to comment.