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The 34 pages that link to Friedmann equations, each with the reason it gives.

• Dark energyRelated: They connect cosmic energy density and pressure to the expansion rate.

• Cosmic inflationRelated: They provide the framework for describing accelerated expansion in cosmology.

• Einstein field equationsBroader topic: They govern the expansion of idealized large-scale universes.

• Cosmological constantRelated: They show how the cosmological constant affects cosmic expansion.

• Cosmological principleRelated: They translate the principle’s symmetries into predictions for cosmic expansion.

• Hubble constantRelated: They connect the expansion rate to cosmic contents and spatial curvature.

• Lambda-CDM modelRelated: They translate the model’s contents into predictions for the universe’s expansion history.

• CosmologyRelated: They translate cosmic matter, radiation, and dark energy into expansion histories.

• Georges LemaîtreRelated: They provided a mathematical route to the expanding solutions Lemaître independently developed.

• Friedmann–Lemaître–Robertson–Walker metricRelated: They determine how matter, radiation, curvature, and dark energy drive the scale factor.

• Scale factorRelated: They determine how the scale factor evolves from the universe’s contents and spatial curvature.

• Comoving distanceNarrower topic: They supply the expansion history used to calculate comoving separation.

• Luminosity distanceNarrower topic: They determine the expansion history used to calculate luminosity distance.

• Alexander FriedmannBroader topic: They express the dynamical content of Friedmann’s cosmological solutions.

• Age of the universeRelated: They connect cosmic contents and expansion history to the elapsed time.

• Hubble parameterRelated: They determine how the Hubble parameter evolves from cosmic energy density and curvature.

• Accelerating expansion of the universeRelated: They connect cosmic ingredients and spatial curvature to expansion and its acceleration.

• Particle horizonRelated: They determine the expansion history used to calculate the horizon.

• Cosmological parametersRelated: They translate density and curvature parameters into an expansion history.

• Lookback timeRelated: They supply the expansion history used to calculate lookback time from redshift.

• Big CrunchRelated: They determine whether expansion can slow, stop, and reverse under a given cosmic model.

• Flatness problemRelated: They show why the density required for flatness changes as the universe expands.

• Big BounceRelated: They describe cosmic contraction and expansion, and reveal where standard assumptions prevent a bounce.

• Static universeRelated: They make clear that a static solution requires a special balance of cosmic contents.

• De Sitter universeNarrower topic: Setting matter density to zero and retaining a positive cosmological constant yields De Sitter expansion.

• Universe (cosmology)Related: They form the mathematical foundation of standard models of cosmic evolution.

• Physical cosmologyBroader topic: They translate the universe’s contents and curvature into its expansion history.

• Expansion of the UniverseRelated: They quantify how cosmic contents govern the expansion history.

• History of general relativityBroader topic: They showed that Einstein’s equations permit expanding or contracting universes.

• Comoving and proper distancesNarrower topic: They determine the scale-factor history that relates comoving and proper distances.

• Inflationary epochRelated: They relate the universe’s expansion rate to the energy driving inflation.

• Shape of the universeRelated: They connect cosmic expansion, energy content, and spatial curvature.

• Timeline of cosmological theoriesBroader topic: They describe how cosmic expansion changes with matter, radiation, and curvature.

• Ultimate fate of the universeRelated: They connect the universe’s contents and spatial curvature to its changing expansion rate.