Dark Energy Takes Over

≈ 9.8 billion years · Structure Formation

Temperature (K): 3.8
When: ≈ 9.8 billion years
Redshift: z ≈ 0.4
Era: Structure Formation
Seconds After Big Bang: 309257914000000000

What Happened

Matter has thinned enough that the cosmological constant dominates the energy budget, and the expansion stops slowing and starts speeding up. Found in 1998 by noticing that distant supernovae were fainter than they had any right to be.

Researchers

Brian Schmidt Albert Einstein Saul Perlmutter Adam Riess

Equations

Hubble's Law Second Friedmann Equation Critical Density Cosmological Equation of State

Theories

Dark Energy Big Bang Cosmology

Referenced by

equation

Cosmological Equation of State Critical Density Hubble's Law Second Friedmann Equation

researcher

Adam Riess Albert Einstein Brian Schmidt Saul Perlmutter

theory

Big Bang Cosmology Dark Energy

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From the Cosmic Timeline database in Notion, last edited 2026-08-21. This page is the row, rendered by the build; nothing on it is written by hand.