# Lambda-CDM model

## Model of Big Bang cosmology / From Wikipedia, the free encyclopedia

#### Dear Wikiwand AI, let's keep it short by simply answering these key questions:

Can you list the top facts and stats about Lambda-CDM model?

Summarize this article for a 10 year old

The **Lambda-CDM**, **Lambda cold dark matter**, or **ΛCDM** model is a mathematical model of the Big Bang theory with three major components:

- a cosmological constant, denoted by lambda (Λ), associated with dark energy
- the postulated cold dark matter, denoted by CDM
- ordinary matter

This article needs additional citations for verification. (February 2024) |

It is referred to as the *standard model* of Big Bang cosmology^{[1]} because it is the simplest model that provides a reasonably good account of:

- the existence and structure of the cosmic microwave background
- the large-scale structure in the distribution of galaxies
- the observed abundances of hydrogen (including deuterium), helium, and lithium
- the accelerating expansion of the universe observed in the light from distant galaxies and supernovae

The model assumes that general relativity is the correct theory of gravity on cosmological scales. It emerged in the late 1990s as a **concordance cosmology**, after a period of time when disparate observed properties of the universe appeared mutually inconsistent, and there was no consensus on the makeup of the energy density of the universe.

Some alternative models challenge the assumptions of the ΛCDM model. Examples of these are modified Newtonian dynamics, entropic gravity, modified gravity, theories of large-scale variations in the matter density of the universe, bimetric gravity, scale invariance of empty space, and decaying dark matter (DDM).^{[2]}^{[3]}^{[4]}^{[5]}^{[6]}