Pome

Proposition 11.45.18132C5E1825BF

Proposition 11.45.18.132C5E1825BF Let $w_ j\in C^\infty (X)$ be real and suppose

\[ \Omega _ j=\eta +\mathrm{dd}^{\mathrm{c}}w_ j>0,\qquad \Omega _ j\longrightarrow \Omega \quad \text{uniformly as }(1,1)\text{-forms}. \]

Put $u_ j=\psi +w_ j$ and $F_ j=\log (\Omega _ j^2/(c_0\mathrm{d}V))$. Let $\rho _ j>0$ be the smooth residual adjoint weight, normalized by

\[ \mathrm{dd}^{\mathrm{c}}(\rho _ j\Omega _ j)=0,\qquad \int _ X\rho _ j\Omega _ j^2=1. \]

Then $F_ j\to F$ uniformly, and the entire sequence satisfies

\[ \rho _ j\Omega _ j^2\rightharpoonup \nu ,\qquad \rho _ j\Omega _ j\rightharpoonup Q,\qquad \rho _ j\, \mathrm{d}W\rightharpoonup \rho \, \mathrm{d}W. \]

Such approximations exist with $w_ j\to w_0$ uniformly and can depend on both curve variables.

Proof. Existence of the smooth positive weights is theorem 11.4.2, applied to the residual metrics $\Omega _ j$ on the surface. Put $\nu _ j=\rho _ j\Omega _ j^2$ and $L_ jh=2\Omega _ j\wedge \mathrm{dd}^{\mathrm{c}}h/\Omega _ j^2$. Distributional Stokes gives $\int L_ jh\, \mathrm{d}\nu _ j=0$. Uniform convergence to the positive form $\Omega $ supplies a common determinant lower bound and gives $L_ jh\to L_ uh$ uniformly for every fixed smooth $h$. Every weak cluster point of the probabilities $\nu _ j$ is therefore invariant for $L_ u$. By theorem 11.45.16, it equals $\nu $, proving convergence of the whole sequence. The same determinant convergence gives $F_ j\to F$ uniformly.

For a smooth real $(1,1)$ test form $\xi $, the ratios $\Omega _ j\wedge \xi /\Omega _ j^2$ converge uniformly to $\Omega \wedge \xi /\Omega ^2$. Consequently,

\[ \int _ X\rho _ j\Omega _ j\wedge \xi =\int _ X\frac{\Omega _ j\wedge \xi }{\Omega _ j^2}\, \mathrm{d}\nu _ j \longrightarrow \int _ X\rho \Omega \wedge \xi . \]

Similarly, the positive densities $p_ j=\Omega _ j^2/\mathrm{d}W$ converge uniformly to $p=\Omega ^2/\mathrm{d}W$. For every $g\in C(X)$,

\[ \int _ Xg\rho _ j\, \mathrm{d}W =\int _ X(g/p_ j)\, \mathrm{d}\nu _ j \longrightarrow \int _ X(g/p)\, \mathrm{d}\nu =\int _ Xg\rho \, \mathrm{d}W. \]

These arguments require no pointwise control of the weights.

For existence, heat-smooth $A$ on the first sphere to positive smooth functions $A_ j$ of the same mean $a$, converging uniformly to $A$. Green inversion gives smooth mean-zero $w_ j(x)$ with $\mathrm{dd}^{\mathrm{c}}w_ j=(A_ j-a)\omega _1$ and $w_ j\to w_0$ uniformly. Their residuals converge uniformly to $\Omega $. Adding $\varepsilon _ j h(x,y)$ for a fixed smooth function depending on both variables and $\varepsilon _ j\to 0$ preserves positivity for all sufficiently small coefficients and supplies nonsymmetric examples. Each $u_ j$ retains the fixed logarithmic divisor, and its non-pluripolar equation has scalar $c_0$ and logarithmic density $F_ j$. $\square$

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