Equation 15 · Part 3 · 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
A third, independent method has entered the field in the past two decades: baryon acoustic oscillations imprinted not on the CMB but on the later, three-dimensional distribution of galaxies themselves. The same sound waves that set the CMB’s acoustic scale also left a faint, statistically detectable preferred separation between galaxies — a standard ruler that can be measured at many different cosmic epochs by surveying galaxy positions and redshifts in bulk. The Dark Energy Spectroscopic Instrument, operating at Kitt Peak with roughly five thousand robotically positioned optical fibers that can each be aimed at a separate pre-selected galaxy or quasar every exposure, released its first-year…
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.