Limitations of anthropic predictions for the cosmological constant $\Lambda$: Cosmic Heat Death of Anthropic Observers

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This paper investigates anthropic bounds on the vacuum energy $\Lambda$.

• We first consider the possibility of cosmic observers existing at any random time (including the future) for constant $\Lambda$, and take into account the suppression of new structure formation as the universe approaches its eternal DeSitter (DS) geometry.
• Structures that collapse prior to the era of $\Lambda$-domination will lose causal contact with our Hubble volume within a finite (short) conformal time $\tau_{\ast}$.
• Any remnants within our Hubble volume then suffer a cosmological heat death after the universe becomes DS.