Quantization of the linearized Einstein–Klein–Gordon system on arbitrary backgrounds and the special case of perturbations in inflation
Quantization of the linearized Einstein–Klein–Gordon system on arbitrary backgrounds and the special case of perturbations in inflation
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DOI:
10.1088/0264-9381/31/21/215004
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发表时间:
2014-03
影响因子:
3.5
通讯作者:
Thomas-Paul Hack
中科院分区:
文献类型:
--
作者:
Thomas-Paul Hack
We quantize the linearized Einstein–Klein–Gordon system on arbitrary on-shell backgrounds in a manifestly covariant and gauge-invariant manner. For the special case of perturbations in inflation, i.e. on-shell backgrounds of Friedmann–Lemaître–Robertson–Walker type, we compare our general quantization construction with the standard approach to the quantum theory of perturbations in inflation. We find that not all local quantum observables of the linearized Einstein–Klein–Gordon system can be split into local observables of scalar and tensor type as in the standard approach. However, we argue that this subclass of observables is sufficient for measuring perturbations that vanish at spatial infinity, which is in line with standard assumptions. Finally, we comment on a recent observation that, upon standard quantization, the quantum Bardeen potentials display a non-local behaviour and argue that a similar phenomenon occurs in any local quantum field theory. It is the hope of the author that the present work may constitute a bridge between the generally applicable and thus powerful framework of algebraic quantum field theory in curved spacetimes and the standard treatment of perturbations in inflation.