2 Proof of the theorem [02G8]
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2 Proof of the theorem
2.1 Preliminary remarks
Uniform control of . Observe that for , hence for all ,
Note that is increasing (hence decreases as ) and satisfies for
In particular is increasing in and
Uniform control of densities. Let denote the (modulus square) of the Jacobian of the mapping , defined through
Let us rewrite the equation as follows
where for
Observe that
hence is uniformly bounded in , . We actually need a slightly stronger information.
Lemma 2.1
There exists and a constant such that for all
Proof of the lemma. Set and observe that
where .
This shows that the densities are uniformly in w.r.t. the normalized volume fomrs .
Since is locally given as the square of the modulus of a holomorphic function which does not vanish identically, there exists such that . Fix satisfying the condition . It follows from Hölder’s inequality that
Setting and using Hölder’s inequality again , we obtain
Now applying again Hölder inequality we get
Therefore denoting by , we have the following uniform estimate
where
2.2 Uniform domination by capacity
We now show that the measure are uniformly strongly dominated by the normalized capacity It actually follows from a carefull reading of the no parameter proof given in [EGZ], [BGZ].
Lemma 2.2
There exists a constant such that for any compact set and ,
Proof: Fix a compact set . Set . Hölder’s inequality yields
It remains to dominate uniformly the normalized volume forms by the normalized capacities . Fix and observe that for any ,
where
is the extremal function of and is the associated capacity of (see [GZ 1] for their properties).
Observe that and , hence the family of functions is a normalized family of psh functions. Thus there exists which depends only on and a constant such that ([Z])
The Alexander-Taylor comparison theorem (see Theorem 7.1 in [GZ 1]) now yields for a constant
We infer that there is a constant such that
2.3 Uniform normalization
The comparison principle (see [K] ,[EGZ]) yields for any and
It is now an exercise to derive from this inequality an a priori estimate,
where (see [EGZ],[BGZ]) is the smallest number satisfying the condition for all such that . Recall from ([GZ 1], Prop. 3.6) that
Since , it follows that
Since is psh and normalized, we know that there is a constant such that for any such . Therefore for any . Finally we obtain the required uniform estimate for all .