On a generalization of binomial coefficients. (Sur une généralisation des coefficients binomiaux.)
On a multiplicative partition function.
On a new family of generalized Stirling and Bell numbers.
On an integer sequence related to a product of trigonometric functions, and its combinatorial relevance.
On colored set partitions of type B n
Generalizing Reiner’s notion of set partitions of type B n, we define colored B n-partitions by coloring the elements in and not in the zero-block respectively. Considering the generating function of colored B n-partitions, we get the exact formulas for the expectation and variance of the number of non-zero-blocks in a random colored B n-partition. We find an asymptotic expression of the total number of colored B n-partitions up to an error of O(n −1/2log7/2 n], and prove that the centralized and...
On entropies of occupancy distributions
On -Thin Sets and -Extensive Graphs
On noncrossing and nonnesting partitions for classical reflection groups.
On partitions avoiding 3-crossings.
On partitions, surjections, and Stirling numbers.
On pattern-avoiding partitions.
On relatively prime sets.
On special partitions of Dedekind- and Russell-sets
A Russell set is a set which can be written as the union of a countable pairwise disjoint set of pairs no infinite subset of which has a choice function and a Russell cardinal is the cardinal number of a Russell set. We show that if a Russell cardinal has a ternary partition (see Section 1, Definition 2) then the Russell cardinal fails to have such a partition. In fact, we prove that if a ZF-model contains a Russell set, then it contains Russell sets with ternary partitions as well as Russell...
On the Borel-Cantelli Lemma and moments
We present some extensions of the Borel-Cantelli Lemma in terms of moments. Our result can be viewed as a new improvement to the Borel-Cantelli Lemma. Our proofs are based on the expansion of moments of some partial sums by using Stirling numbers. We also give a comment concerning the results of Petrov V.V., A generalization of the Borel-Cantelli Lemma, Statist. Probab. Lett. 67 (2004), no. 3, 233–239.
On the density of languages representing finite set partitions.
On the number of m-term zero-sum subsequences
On the number of subsets relatively prime to an integer.
On the uniform generation of modular diagrams.
Optimal bounds for the colored Tverberg problem
We prove a “Tverberg type” multiple intersection theorem. It strengthens the prime case of the original Tverberg theorem from 1966, as well as the topological Tverberg theorem of Bárány et al. (1980), by adding color constraints. It also provides an improved bound for the (topological) colored Tverberg problem of Bárány & Larman (1992) that is tight in the prime case and asymptotically optimal in the general case. The proof is based on relative equivariant obstruction theory.
Optimal matrices of partitions and an application to Souslin trees
The basic result of this note is a statement about the existence of families of partitions of the set of natural numbers with some useful properties, the n-optimal matrices of partitions. We use this to improve a decomposition result for strongly homogeneous Souslin trees. The latter is in turn applied to separate strong notions of rigidity of Souslin trees, thereby answering a considerable portion of a question of Fuchs and Hamkins.