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arXiv · 1211.0431

Local Thermal Equilibrium and KMS states in Curved Spacetime

Christoph Solveen
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Abstract

On the example of a free massless and conformally coupled scalar field, it is argued that in quantum field theory in curved spacetimes with time-like Killing field, the corresponding KMS states (generalized Gibbs ensembles) at parameter β>0 need not possess a definite temperature in the sense of the zeroth law. In fact, these states, although passive in the sense of the second law, are not always in local thermal equilibrium (LTE). A criterion characterizing LTE states with sharp local temperature is discussed. Moreover, a proposal is made for fixing the renormalization freedom of composite fields which serve as "thermal observables" and a new definition of the thermal energy of LTE states is introduced. Based on these results a general relation between the local temperature and the parameter β is established for KMS states in (Anti) de Sitter spacetime.

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Christoph Solveen. 2012-11-02. Local Thermal Equilibrium and KMS states in Curved Spacetime. https://doi.org/10.1088/0264-9381%2F29%2F24%2F245015

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