Equation 1 · Part 7 · From Origins to Frontier: A History of Precision Cosmology
subscript
subscript
What this part means
The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.
Its job in the formula
A subscript distinguishes a version, component, step, or member of a quantity. It does not automatically mean multiplication.
Full expression→subscript→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.
Open the illustrated subscripts: which member of a family? guide →
Sources cited in the surrounding passage
These citations provide research context; check each source for the exact claim it supports.