2022/12/20 by A.A. Tseytlin, Tseytlin, A. A. · 1 citation
Physics and Astronomy · #Atomic and Subatomic Physics Research #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Quantum Electrodynamics and Casimir Effect #Quantum, superfluid, helium dynamics
paper · pdf · doi:10.48550/arxiv.2212.10599
openalex publication_date 2022/12/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We review and elaborate on some aspects of the classically scale-invariant renormalizable 4-derivative scalar theory L= ϕ ∂4 ϕ+ g (∂ ϕ)4. Similar models appear, e.g., in the context of conformal supergravity or in the description of the crystalline phase of membranes. Considering this theory in Minkowski signature we suggest how to define Poincare-invariant scattering amplitudes by assuming that only massless oscillating (non-growing) modes appear as external states. In such shift-symmetric interacting theory there are no IR divergences despite the presence of 1/q4 internal propagators. We discuss how non-unitarity of this theory manifests itself at the level of the one-loop massless scattering amplitude.