An acyclic vertex coloring of a graph is a proper vertex coloring such that there are no bichromatic cycles. The acyclic chromatic number of G, denoted ...
We show that the joint distribution of the number of singleton pairs and the number of adjacency pairs is symmetric over the set partitions of type Bn without zero-block, in analo...
For an operator T ∈ B(X, Y ), we denote by am(T), cm(T), dm(T), and tm(T) its approximation, Gelfand, Kolmogorov, and absolute numbers. We show that, for any infinite dimensiona...
A k-plex of a latin square is a collection of cells representing each row, column, and symbol precisely k times. The classic case of k = 1 is more commonly known as a transversal....
Minkowski’s second theorem on successive minima gives an upper bound on the volume of a convex body in terms of its successive minima. We study the problem to generalize Minkowsk...
Christian Bey, Martin Henk, Matthias Henze, Eva Li...