Friedmann equations - Wikipedia
The Friedmann equations, also known as the Friedmann–Lemaître (FL) equations, are a set of equations in physical cosmology that govern cosmic expansion in homogeneous and isotropic models of the universe within the context of general relativity.
The Friedmann Equations Explained: A Complete Guide
The Friedmann equations are a set of dynamical equations describing the expansion of the universe based on its matter content. The Friedmann equations provide a model for describing many of the observational features of the universe and …
The Most Important Equation In The Universe - Forbes
2018年4月17日 · Last week, Perimeter Institute ran a feature where they asked 14 scientists what their favorite equation was, and why. There were many great answers from many different areas of research, from...
17.3: The Friedmann Equation and the Fate of the Universe
2024年8月11日 · The Friedmann equation alone determines whether the Universe keeps expanding forever or eventually re-collapses; whether the scale factor S grows or shrinks is determined here only by the density of the Universe, which also determines its overall geometry.
A single equation can describe the full history of the universe - Big Think
2021年10月26日 · And yet, when it comes to understanding the universe, including how it evolves over time, both far into the future and way back into the distant past, there’s only one equation needed to describe...
This is the most important equation in cosmology - Big Think
2022年6月9日 · Although Hubble’s law, v = Hr, was the equation that established an observational basis for the expanding Universe, the Friedmann equations, derived years prior, provided the foundation for...
The Friedmann Equation - HyperPhysics
Alexander Friedmann of Russia is credited with developing a dynamic equation for the expanding universe in the 1920s. This was a time when Einstein, Willem de Sitter of the Netherlands, and Georges Lemaitre of Belgium were also working on equations to model the universe.
The Most Important Equation In The Universe - Medium
2018年4月24日 · Just one equation relates the expansion of space to all the matter and energy we have. If you know this, you can know the fate of the Universe. Starts With A Bang! Last week, Perimeter Institute...
equations that describe the evolution of the universe for any given energy and matter content with an energy density given by ˆ(t) and a pressure p(t): a_(t) a(t) 2 + K a(t)2 = 8ˇG 3 ˆ(t); (1) a (t) a(t) = 4ˇG 3 (ˆ(t) + 3p(t)): (2) From the two Friedmann equations we also derived the continuity equation ˆ_(t) + 3H(t)(ˆ(t) + p(t)) = 0; (3)
7.5: The Friedmann Equation - Physics LibreTexts
A density greater than the critical density will produce a universe with a spherical geometry, and anything less will produce a universe with a saddle-like geometry.