How stress-energy deformations reshape quantum field theories

Researchers found a one-parameter family of stress-tensor deformations that unifies three regimes: irrelevant (vanish at high energy), marginal (no energy scale), and relevant (dominate physics). In four-dimensional electromagnetism and 2D integrable models, they solved the equations exactly, revealing that the marginal case recovers a known symmetry-preserving deformation. The framework suggests a deep organizing principle behind duality-invariant quantum field theories.