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Equation 12 · Part 1 · From Origins to Frontier: A History of Precision Cosmology

Symbol H_0

H0H_0
H0H_0

What this part means

the reported a local.

Its job in the formula

H0H_0 is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Where the article explains it

The SH0ES team’s 2022 analysis, using Hubble Space Telescope observations of Cepheids in the hosts of forty-two Type Ia supernovae, reported a local H0H_0 of 73.04 ± 1.04 kilometers per second per megaparsec [ 7 ] .

The passage around this formula

…one using the tip of the red-giant branch, with only partial convergence. On the early-universe side, the acoustic scale itself is not in question, but the assumed pre-recombination physics used to convert it into H0H_0 could in principle be incomplete — an early form of dark energy, extra relativistic species, or modified matter behavior before recombination could each shift the inferred r∗r_* and thus H0H_0 without Planck’s raw measurement being wrong. No single proposed fix currently resolves the tension…

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A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

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Sources cited in the article section

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