A look at the Hubble speed from first principles

Fabrizio Renzi; Alessandra Silvestri

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arXiv · 2011.10559

A look at the Hubble speed from first principles

Fabrizio Renzi·Alessandra Silvestri

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Abstract

We introduce a novel way of measuring $H_0$ from a combination of independent geometrical datasets, with no need of calibration nor of the choice of a cosmological model. We build on the {\it distance duality relation} which sets the ratio of the luminosity and angular diameter distance to a fixed scaling in redshift for any metric theory of gravity with standard photon propagation and constitutes a founding block of any theory describing our Universe. Our method provides the unprecedented possibility of determining $H_0$ from first principles, unleashing the measurement of this fundamental constant from calibration and assumption of a cosmological model. We find $H_0=69.5 \pm 1.7$ km/s/Mpc at $68\%$ C.L. showing that the Hubble constant can be constrained at percent level with minimal assumptions.

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Fabrizio Renzi, Alessandra Silvestri. 2020-11-20. A look at the Hubble speed from first principles. https://arxiv.org/abs/2011.10559

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