Friday, 24 August 2007

reference request - Inverse limit in metric geometry

Question. Did you ever see inverse limits to be used (or even seriousely considered) anywhere in metric geometry (but NOT in topology)?



The definition of inverse limit for metric spaces is given below. (It is usual inverse limit in the category with class of objects formed by metric spaces and class of morphisms formed by short maps.)



Definition.
Consider an inverse system of metric spaces XnXn and short maps phim,n:XmtoXnphim,n:XmtoXn for mgenmgen;
i.e.,(1) phim,ncircphik,m=phik,nphim,ncircphik,m=phik,n for any triple kgemgenkgemgen and (2) for any nn, the map phin,nphin,n is identity map of XnXn.



A metric space XX is called inverse limit of the system (phim,n,Xn)(phim,n,Xn) if its underlying space consists of all sequences xninXnxninXn such that phim,n(xm)=xnphim,n(xm)=xn for all mgenmgen and for any two such sequences (xn)(xn) and (yn)(yn) the distance is defined by



|(xn)(yn)|=limntoinfty|xnyn|.|(xn)(yn)|=limntoinfty|xnyn|.



Why: I have a theorem, with little cheating you can stated it this way: The class of metric spaces which admit path-isometries to Euclidean dd-spaces coincides with class of inverse limits of dd-polyhedral spaces.
In the paper I write: it seems to be the first case when inverse limits help to solve a natural problem in metric geometry. But I can not be 100% sure, and if I'm wrong I still have time to change this sentence.

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