The intersection shadow theorem of Katona is an important tool in extremal set theory. The original proof is purely combinatorial. The aim of the present paper is to show how it is using linear independence latently.

We are interested in classifying those sets of primes P such that when we sieve out the integers up to x by the primes in P we are left with roughly the expected number of unsieved integers. In particular, we obtain the first general results for sieving an interval of length x with primes including some in ( √ x, x], using methods motivated by additive combinatorics.

This booklet develops in nearly 200 pages the basics of combinatorial enumeration through an approach that revolves around generating functions. The major objects of interest here are words, trees, graphs, and permutations, which surface recurrently in all areas of discrete mathematics. The text presents the core of the theory with chapters on unlabelled enumeration and ordinary generating func...

The famous Erd˝ os-Heilbronn conjecture plays an important role in the development of additive combinatorics. In 2007 Z. W. Sun made the following further conjecture (which is the linear extension of the Erd˝ os-Heilbronn conjecture): For any finite subset A of a field F and nonzero elements a where p(F) is the additive order of the multiplicative identity of F , and δ ∈ {0, 1} takes the value ...

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 The modern face of enumerative combinatorics. . . . . . . . . . . . . . . . . . . . . . . . 3 2 Algebraic invariants and combinatorial structures . . . . . . . . . . . . . . . . . . . . . 4 3 Combinatorics and geometry. . . . . . . . . . . . . . . . . . . . . . ...

With the untimely passing of this still-young mathematician, the world has lost an “original”. Hunter Snevily came to the University of Illinois in the mid-1980s and became only my fifth Ph.D. student, completing his thesis in 1991. I was also young then and learned as much from him as he did from me. Hunter’s main work was in extremal set theory, where he made a significant contribution. As a ...

The famous Erd˝ os-Heilbronn conjecture plays an important role in the development of additive combinatorics. In 2007 Z. W. Sun made the following further conjecture (which is the linear extension of the Erd˝ os-Heilbronn conjecture): For any finite subset A of a field F and nonzero elements a where p(F) is the additive order of the multiplicative identity of F , and δ ∈ {0, 1} takes the value ...

Given a graph H, the Ramsey number r(H) is the smallest natural number N such that any two-colouring of the edges of KN contains a monochromatic copy of H. The existence of these numbers has been known since 1930 but their quantitative behaviour is still not well understood. Even so, there has been a great deal of recent progress on the study of Ramsey numbers and their variants, spurred on by ...

Chvátal’s conjecture in extremal combinatorics asserts that for any decreasing family F of subsets of a finite set S, there is a largest intersecting subfamily of F consisting of all members of F that include a particular x ∈ S. In this paper we reformulate the conjecture in terms of influences of variables on Boolean functions and correlation inequalities, and study special cases and variants ...