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1. Accelerating Expansion Of The Universe

   Linked via "Friedmann acceleration equation"

   Theoretical Framework: Dark Energy and the Equation of State
   To model this acceleration within General Relativity, the behavior of the dominant cosmic component must satisfy the second Friedmann acceleration equation, which dictates the rate of change of the scale factor $\dot{a}(t)$:
   $$\frac{\ddot{a}}{a} = -\frac{4\pi G}{3} (\rho c^2 + 3P)$$
   For $\ddot{a} > 0$ (acceleration), the term $(\rho c^2 + 3P)$ must be negative. Since energy density ($\rho$) is positi…