ScalingStacks

Proof. [01BC]

Original official author HTML, exact retained edition. Historical TeX conversion verdicts remain unchanged. Cited-edition alignment and mathematical self-containment are not assessed.

Complete original source context · Original author HTML

Proof.

We may assume φ≤0\varphi\leq 0. Set μt:=MA⁡(φ⟨t⟩)\mu_{t}:=\MA(\varphi^{\langle t\rangle}). Since (6.2) applies to bounded ω\omega-psh functions by Proposition 6.3, we get

Eω(φ⟨t/2⟩)−Eω(φ⟨t⟩)≥1n+1∫(φ⟨t/2⟩−φ⟨t⟩)μt=1n+1∫0t/2μt{φ⟨t/2⟩−φ⟨t⟩≥s}ds≥1n+1∫0t/2μt{φ⟨t/2⟩−φ⟨t⟩≥t/2}ds=t2​(n+1)μt{φ≤−t},E_{\omega}(\varphi^{\langle t/2\rangle})-E_{\omega}(\varphi^{\langle t\rangle})\geq\frac{1}{n+1}\int(\varphi^{\langle t/2\rangle}-\varphi^{\langle t\rangle})\mu_{t}=\frac{1}{n+1}\int_{0}^{t/2}\mu_{t}\left\{\varphi^{\langle t/2\rangle}-\varphi^{\langle t\rangle}\geq s\right\}\,ds\\ \geq\frac{1}{n+1}\int_{0}^{t/2}\mu_{t}\left\{\varphi^{\langle t/2\rangle}-\varphi^{\langle t\rangle}\geq t/2\right\}\,ds=\frac{t}{2(n+1)}\mu_{t}\left\{\varphi\leq-t\right\},

where μt=MA⁡(φ⟨t⟩)\mu_{t}=\MA(\varphi^{\langle t\rangle}). Since limt→∞Eω​(φ⟨t/2⟩)=limt→∞Eω​(φ⟨t⟩)=Eω​(φ)\lim_{t\to\infty}E_{\omega}(\varphi^{\langle t/2\rangle})=\lim_{t\to\infty}E_{\omega}(\varphi^{\langle t\rangle})=E_{\omega}(\varphi) by the continuity of EωE_{\omega} along decreasing sequences, the proof is complete. ∎

Original mathematics by the credited authors. Source-backed reader collection; mathematical self-containment is not assessed.