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arXiv · 2305.00711

The Hawking Energy in a Perturbed Friedmann-Lema\^{i}tre Universe

Dennis Stock·Enea Di Dio·Ruth Durrer
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Abstract

Hawking's quasi-local energy definition quantifies the energy enclosed by a spacelike 2-sphere in terms of the amount of lightbending on the sphere caused by the energy distribution inside the sphere. This paper establishes for the first time a direct connection between the formal mathematical definition of a quasi-local energy and observations, in the context of cosmological perturbation theory. This is achieved by studying the Hawking Energy of spherical sections of the past lightcone of a cosmic observer in a perturbed Friedmann-Lema\^{i}tre spacetime. We express the Hawking Energy in terms of gauge-invariant perturbation variables and comment on the cosmic observables needed to in principle measure it. We then calculate its angular power spectrum and interpret its contributions.

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Dennis Stock, Enea Di Dio, Ruth Durrer. 2023-05-01. The Hawking Energy in a Perturbed Friedmann-Lema\^{i}tre Universe. https://doi.org/10.1088/1475-7516%2F2023%2F08%2F033

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