EntityQ1332997· pop 20· linked from 73 articlesscale factorSign in to saveparameter which characterizes the expansion of the universeConnectionsHubble–Lemaître lawEntitychronology of the universeEntityBig BangEntityInternational Standard Book NumberEntitygeneral relativityEntityspecial relativityEntityphotonEntityWayback MachineEntitysupernovaEntitydigital object identifierEntityderivativeEntityradiationEntityneutrinoEntityredshiftEntitymass–energy equivalenceEntitycosmic microwave backgroundEntitydark energyEntityobservable universeEntitybibcodeEntityOxford University PressEntityCategoriesPhysical cosmology