 Strong energy condition in a Friedmann universe

ID: strong-energy-condition-in-a-friedmann-universe

Codex  0 Created 2026-09-24 Updated 2026-09-24

With zero cosmological constant, the condition

ρ + 3 P \geq 0

implies

\overset{a}{¨} \leq 0

and

\dot{H} \leq - H^{2}, \frac{d}{d t} (H^{- 1}) \geq 1

wherever

H \neq = 0

 New to topics? Read the docs here!