Subharmonic function: Difference between revisions

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<math display="block"> \|M \varphi\|_{L^2(\mathbf{T})}^2 \le C^2 \, \int_0^{2\pi} \varphi(e^{i\theta})^2 \, d\theta.</math>
 
If ''f'' is a function holomorphic in Ω and 0&nbsp;< ''p''&nbsp;< ∞, then the preceding inequality applies to ''φ''&nbsp;= |''f''&hairsp;{{hair space}}|{{i sup|''p''/2}}. It can be deduced from these facts that any function ''F'' in the classical Hardy space ''H<sup>p</sup>'' satisfies
<math display="block"> \int_0^{2\pi} \left( \sup_{0 \le r < 1} \left|F(r e^{i\theta})\right| \right)^p \, d\theta \le C^2 \, \sup_{0 \leq r < 1} \int_0^{2\pi} \left|F(re^{i\theta})\right|^p \, d\theta.</math>
With more work, it can be shown that ''F'' has radial limits ''F''(''e''{{i sup|''iθ''}}) almost everywhere on the unit circle, and (by the [[dominated convergence theorem]]) that ''F<sub>r</sub>'', defined by ''F<sub>r</sub>''(''e''{{i sup|''iθ''}})&nbsp;= ''F''(''r''&hairsp;{{hair space}}''e''{{i sup|''iθ''}}) tends to ''F'' in ''L''<sup>''p''</sup>('''T''').
 
== Subharmonic functions on Riemannian manifolds ==