Quantum Inequalities from the Second Law

• URL: http://arxiv.org/abs/2608.11817v1
• Date: Wed, 12 Aug 2026 08:58:51 GMT
• Title: Quantum Inequalities from the Second Law
• Abstract summary: Quantum field theory allows local violations of the classical energy conditions, such as regions of negative energy density.<n>We present a framework that couples the field to a small thermal detector.<n>The detector acts as a physical probe of the field's energy density and, by the non-negativity of the entanglement entropy between the two systems, one can show that its heat loss is bounded from below by a state-independent quantity.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Quantum field theory allows local violations of the classical energy conditions, such as regions of negative energy density. The Ford-Roman quantum inequalities quantify how negative these regions can be and for how long. We present a derivation of these inequalities from the second law of thermodynamics, in an operational framework that couples the field to a small thermal detector. The detector acts as a physical probe of the field's energy density and, by the non-negativity of the entanglement entropy between the two systems, one can show that its heat loss is bounded from below by a state-independent quantity.

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