Saturation of the Quantum Null Energy Condition in Far-From-Equilibrium Systems

Understand

The Quantum Null Energy Condition (QNEC) is a new local energy condition that a general Quantum Field Theory (QFT) is believed to satisfy, relating the classical null energy condition (NEC) to the second functional derivative of the entanglement entropy in the corresponding null direction.

• We present the first series of explicit computations of QNEC in a strongly coupled QFT, using holography.
• We consider the vacuum, thermal equilibrium, a homogeneous far-from-equilibrium quench as well as a colliding system that violates NEC.
• For vacuum and the thermal phase QNEC is always weaker than NEC.