标题： 关于微扰代数量子场论中KMS状态的稳定性 显示英文标题

标题： On the stability of KMS states in perturbative algebraic quantum field theories

摘要： 我们分析了在弗雷登哈根和林德纳 \cite{FredenhagenLindner}构造的微扰代数量子场论框架中，相互作用的大量标量场在闵可夫斯基时空传播时所表现出的KMS态的稳定性性质。特别是，我们证明了当相互作用拉格朗日量具有紧致空间支撑时，回到平衡性质是有效的。令人惊讶的是，如果考虑绝热极限，即当相互作用拉格朗日量在空间平移下不变时，这一性质不再成立。因此，在绝热极限下，由自由动力学演化的一个微扰相互作用理论的平衡态不再收敛到自由平衡态。实际上，我们证明了其遍历均值收敛到自由理论的一个非平衡稳态。 显示英文摘要

摘要： We analyze the stability properties shown by KMS states for interacting massive scalar fields propagating over Minkowski spacetime, recently constructed in the framework of perturbative algebraic quantum field theories by Fredenhagen and Lindner \cite{FredenhagenLindner}. In particular, we prove the validity of the return to equilibrium property when the interaction Lagrangian has compact spatial support. Surprisingly, this does not hold anymore, if the adiabatic limit is considered, namely when the interaction Lagrangian is invariant under spatial translations. Consequently, an equilibrium state under the adiabatic limit for a perturbative interacting theory evolved with the free dynamics does not converge anymore to the free equilibrium state. Actually, we show that its ergodic mean converges to a non equilibrium steady state for the free theory.