Quantum tunneling in the presence of Noether charges
Year: 2026
Type: article
Abstract: We provide a complete first-principles based discussion of quantum tunneling out of initial states carrying a conserved Noether charge. Our main result is a simple, unambiguous Euclidean-time prescription for the calculation of tunneling rates out of such states. By relying on a combination of the direct approach and the steadyon framework for the evaluation of real-time path integrals, our derivation offers full transparency of its underlying assumptions, and is independent of any generalizations. This strategy also offers a simple explanation for the emergence of complex saddle points for such systems, justifying techniques postulated by earlier works. Our analysis furthermore offers the first results for initial states with both a conserved Noether charge and a nontrivial energy. We first illustrate the main conceptual points of our analysis for the simple example of a point particle in two spatial dimensions carrying a conserved angular momentum. Then, we generalize our results to the case of multiple dimensions and an arbitrary conserved Noether charge, providing an easy-to-implement prescription for the calculation of the tunneling rate. We furthermore apply our results to the example of a complex scalar field subject to a global U ( 1 ) -symmetry with associated charge. These results provide a reliable foundation for the calculation of tunneling rates in applications in finite-density and charge-asymmetric systems.
DOI: 10.1103/b3z7-t8m9
Authors: Giulio Barni, Thomas Steingasser
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Awards: G1175115578, G176269601, G1764267590, G210041235, G2262748287, G2390397592, G24120701, G2601397997, G282847690, G294895050, G300979063, G3189457805, G34346518, G3480869486, G3681454997, G4042783231, G425668148, G4348135621, G4442677895, G4526231891, G4728762194, G5080475149, G5195188938, G586857820, G6874468849, G6946463100, G7084143925, G8389516595, G883791370
OpenAlex ID: W7154096292