Field theory and renormalization far from equilibrium

The National Science Foundation Division of Physics awarded $100,000 to the Research Foundation of the City University of New York on August 15, 2026, under the Mathematical and Physical Sciences program (CFDA 47.049) to fund field theory research activities led by Professor Vladimir Rosenhaus at the Graduate Center of the City University of New York.

The award supports development of analytic methods for quantum field theory in non-equilibrium states, with focus on turbulent energy cascades across weakly and strongly interacting regimes. The research employs artificial intelligence as a tool for theoretical discovery to construct new solvable quantum field theories that illuminate far-from-equilibrium dynamics. The project will examine how interactions are renormalized in nonthermal flux states and how this controls energy transfer across scales, with specific work on renormalization group flows in stationary cascade states and loop corrections to the wave kinetic equation. Research activities span high-energy physics, condensed matter physics, atomic physics, plasma physics, and nonlinear dynamics.

The recipient will mentor graduate students and postdoctoral researchers, develop new graduate-level special topics courses based on the research outcomes, deliver public lectures, and organize scientific workshops. Performance of work occurs in New York, New York, with period of performance from award date through July 31, 2028. This is a project grant, the assistance type for direct support of investigator-initiated research.

Abstract

This award funds the research activities of professor vladimir rosenhaus at the graduate center of the city university of new york. Many physical systems operate far from equilibrium, including ultracold quantum gases, plasmas, nonlinear optical media, and turbulent fluids. Although quantum field theory has been extraordinarily successful in describing matter near the vacuum and in thermal equilibrium, a comparable theoretical description for strongly interacting systems far from equilibrium remains largely undeveloped. This project seeks to establish such a framework by developing analytic methods for non-equilibrium states exhibiting turbulent energy cascades across weakly and strongly interacting regimes. The project will also exploit artificial intelligence as a tool for theoretical discovery, with the goal of constructing new solvable quantum field theories that illuminate far-from-equilibrium dynamics. As a result, research in this area advances the national interest by promoting the progress of science in one of its most fundamental directions: the discovery and understanding of new physical laws, while strengthening connections between high-energy physics, condensed matter physics, atomic physics, plasma physics, and nonlinear dynamics. This project is also envisioned to have significant broader impacts. Professor rosenhaus will mentor graduate students and postdocs who will be involved in the research, develop new special topics graduate courses based on the research, give public lectures, and organize scientific workshops. More technically, this project will study how interactions are renormalized in nonthermal flux states and how this controls the transfer of energy across scales. At weak coupling, the project will formulate renormalization group flows directly in stationary cascade states, rather than in the vacuum or a thermal ensemble, and compute loop corrections to the wave kinetic equation using schwinger-keldysh methods. At strong coupling, the project will exploit large-N techniques in far-from-equilibrium settings to obtain renormalized kinetic equations that remain valid at all couplings. For large-N vector and multi-component gross-pitaevskii models, these equations will characterize how the effective interaction evolves along the cascade and determine when the dynamics approaches the critical-balance regime, in which nonlinear and linear effects become comparable in the infrared. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are not planned for this award.