# Cover n points with n disjoint unit disks

This is a problem I saw on Peter Winkler's column on communication of the ACM(might be under a pay wall). It is open.

What is the largest $n$, such that you can always cover a given set of $n$ points with $n$ disjoint unit disks?

I believe the current upper bound is $60$.

I would like to know more reference on this problem. Currently I don't even know what field would study problems like this.

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Discrete Geometry? – Yuval Filmus Jun 2 '11 at 16:44
Discrete and/or computational geometry are generic labels for this kind of problem. – yasmar Jun 2 '11 at 16:48
A related question on MathOverflow: mathoverflow.net/questions/20558/… – Jonas Meyer Jun 2 '11 at 17:35