[ \rho_{\text{DE}} = \frac{\Lambda}{8\pi G}, \quad \dot{S}_{\text{horizon}} = \frac{2\pi}{G} \dot{r}_h^2 \geq 0 ]
If you’d like, I can then help you (e.g., the introduction, a technical derivation, or a comparison of their views on emergence vs. fundamentalism). Hypothetical Paper Title: Emergence, Eternity, and Effective Fields: Reconciling String Theory and the Cosmological Arrow of Time brian greene sean carroll
[ \frac{d S_{\text{CG}}}{dt} = \sigma(t) \geq 0 ] with ( \sigma(t) ) the entropy production rate from stringy UV modes falling across the horizon. We postulate a boundary condition at ( t = t_{\text{initial}} ): We postulate a boundary condition at ( t
Without this condition, time-reversal symmetry of the fundamental theory allows both entropy increase and decrease, contradicting observation. [ \rho_{\text{DE}} = \frac{\Lambda}{8\pi G}
The entropy of the cosmological horizon is [ S_{\text{dS}} = \frac{A}{4G} = \frac{3\pi}{G\Lambda} ] where ( \Lambda > 0 ) is the cosmological constant.
We define a coarse-grained entropy ( S_{\text{CG}}(t) ) that increases monotonically: