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arXiv · 0808.2174

Group Averaging of massless scalar fields in 1+1 de Sitter

Donald Marolf·Ian A. Morrison
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Abstract

Perturbative gravity in global de Sitter space is subject to so-called linearization stability constraints: If they are to couple consistently to the gravitational field, quantum states must be invariant under the de Sitter isometries. While standard Fock spaces contain no de Sitter-invariant states apart from (possibly) the vacuum, a full Hilbert space of de Sitter-invariant quantum states can be constructed via group averaging techiniques. We re-examine the simple toy model of de Sitter group averaging given by the free 1+1 scalar field, expanding on an earlier analysis by Higuchi. Our purpose is twofold: to include the scalar zero-mode, and to explicitly count the number of de Sitter-invariant states as a function of an appropriately defined energy.

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Donald Marolf, Ian A. Morrison. 2008-10-28. Group Averaging of massless scalar fields in 1+1 de Sitter. https://doi.org/10.1088/0264-9381%2F26%2F3%2F035001

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