Editing Dark Energy (section)

=== Equation of State for Dark Energy ===
The '''equation of state''' parameter <math>w</math> characterizes the relationship between the pressure <math>p</math> and the energy density <math>\rho</math> of Dark Energy:

<math>
w = \frac{p}{\rho}
</math>

For the cosmological constant, <math>w</math> is exactly -1, meaning that the pressure is negative and equal in magnitude to the energy density. This negative pressure is what drives the accelerated expansion of the universe. However, if Dark Energy is modeled as a dynamic field (such as quintessence), <math>w</math> could differ from -1 and even evolve over time.