2024/02/22 by Nick E. Mavromatos, Mavromatos, Nick E., Sarben Sarkar +1 · 1 voice · 1 citation
Physics and Astronomy · #Experimental and Theoretical Physics Studies #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Noncommutative and Quantum Gravity Theories #Quantum Mechanics and Non-Hermitian Physics #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.48550/arxiv.2402.14513
openalex publication_date 2024/02/22 · arxiv published 2024/02/22 · arxiv updated 2024/07/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This paper considers the possibility that, starting from a relativistic Hermitian quantum field theory in the ultraviolet (UV) regime, and applying a non-perturbative renormalization-group (RG) flow, we arrive at a situation where there are infrared (IR) singularities in the RG flow of couplings. The latter can be resolved by assuming that the theory can have a phase described by a related non-Hermitian PT-symmetric modification in the IR. The UV-to-IR (Hermitian-to-PT-symmetric) transition can occur in a single renormalization-group flow of the pertinent couplings, as demonstrated in concrete examples. When embedded in a gravitational setting such a transition can lead to a repulsive gravity phase. If there is a RG flow to a repulsive PT -symmetric gravity, then this would be an alternative to dark energy. The discussion here is presented in the context of a string-inspired Chern-Simons gravitational effective action, which involves a pseudoscalar (axion-like) field coupled to Abelian gauge fields and gravity; it may also hold more generally in gravity with torsion. The validity of such a scenario in realistic theories might alleviate the need for de Sitter phases in the current epoch of cosmological evolution, thus avoiding their associated conceptual and technical complications.