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Discrete tomography and plane partitions. (English) Zbl 1259.05015

Summary: A plane partition is a \(p\times q\) matrix \(A=(a_{ij})\), where \(1\leqslant i\leqslant p\) and \(1\leqslant j\leqslant q\), with non-negative integer entries, and whose rows and columns are weakly decreasing.
From a geometric point of view plane partitions are equivalent to pyramids, subsets of the integer lattice \(\mathbb Z^{3}\) which play an important role in discrete tomography. As a consequence, some typical problems concerning the tomography of discrete lattice sets can be rephrased and considered via plane partitions.
In this paper we focus on some of them. In particular, we get a necessary and sufficient condition for additivity, a canonical procedure for checking the existence of (weakly) bad configurations, and an algorithm which constructs minimal pyramids (with respect to the number of levels) with assigned projection of a bad configurations.

MSC:

05A17 Combinatorial aspects of partitions of integers
05D05 Extremal set theory
11P81 Elementary theory of partitions
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