Equation 1 · Part 4 · From Origins to Frontier: A History of Precision Cosmology
Symbol z_*
What this part means
occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.
Its job in the formula
occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.
Full expression→Symbol z_*→Article meaning
The passage around this formula
The European Space Agency’s Planck satellite, launched in 2009 and operating until 2013, extended this to still finer angular resolution and a wider frequency range, cooling its bolometer detectors to a fraction of a degree above absolute zero to suppress instrumental noise. Planck’s 2018 final cosmological parameter release fit the standard six-parameter flat Lambda-CDM model to its temperature and polarization data, reporting the acoustic scale — the characteristic angular size of the sound-wave pattern imprinted on the CMB — to 0.03 percent precision, a cold dark matter density of 0.120 ± 0.001 (in units of the density parameter times the reduced Hubble parameter squared), and a Hubble…
Learn the underlying idea
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 surrounding passage
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