Add to ORKGFix r ≥ 2 and a collection of r-uniform hypergraphs H. What is the minimum number of edges in an H-free r-uniform hypergraph with chromatic number greater than k? We investigate this question for various H. Our results include the following: • An (r, l)-system is an r-uniform hypergraph with every two edges sharing at most l vertices. For k sufficiently large, there is an (r, l)-system with chromatic number greater than k and number of edges at most c(kr−1 log k)l/(l−1), where c =
AbstractThe following dual version of Turán's problem is considered: for a given r-uniform hypergrap...
AbstractThe upper chromatic number χ¯(H) of a hypergraph H=(X,E) is the maximum number k for which t...
Let F be a family of r-uniform hypergraphs. The chromatic threshold of F is the infimum of all non-n...
Fix r ≥ 2 and a collection of r-uniform hypergraphs H. What is the minimum number of edges in an H-f...
AbstractThis work deals with a classical combinatorial problem of P. Erdős and A. Hajnal concerning ...
AbstractLet H be a hypergraph. For a k-edge coloring c:E(H)→{1,…,k} let f(H,c) be the number of comp...
Abstract. For k-uniform hypergraphs F and H and an integer r ≥ 2, let cr,F (H) denote the number of ...
In this thesis we study some extremal problems related to colorings and list colorings of graphs and...
Fix an integer k ≥ 3. A k-uniform hypergraph is simple if every two edges share at most one vertex. ...
A set A of vertices in an r-uniform hypergraph HH is covered in HH if there is some vertex u∉...
Fix an integer k ≥ 3. A k-uniform hypergraph is simple if every two edges share at most one vertex. ...
AbstractFix l⩾r⩾2. Let Hl+1(r) be the r-uniform hypergraph obtained from the complete graph Kl+1 by ...
Abstract. Let m∗(n) be the minimum number of edges in an n-uniform sim-ple hypergraph that is not tw...
A set A of vertices in an r-uniform hypergraph HH is covered in HH if there is some vertex u∉...
A set A of vertices in an r-uniform hypergraph H is covered inH if there is some vertex u∉ A such th...
AbstractThe following dual version of Turán's problem is considered: for a given r-uniform hypergrap...
AbstractThe upper chromatic number χ¯(H) of a hypergraph H=(X,E) is the maximum number k for which t...
Let F be a family of r-uniform hypergraphs. The chromatic threshold of F is the infimum of all non-n...
Fix r ≥ 2 and a collection of r-uniform hypergraphs H. What is the minimum number of edges in an H-f...
AbstractThis work deals with a classical combinatorial problem of P. Erdős and A. Hajnal concerning ...
AbstractLet H be a hypergraph. For a k-edge coloring c:E(H)→{1,…,k} let f(H,c) be the number of comp...
Abstract. For k-uniform hypergraphs F and H and an integer r ≥ 2, let cr,F (H) denote the number of ...
In this thesis we study some extremal problems related to colorings and list colorings of graphs and...
Fix an integer k ≥ 3. A k-uniform hypergraph is simple if every two edges share at most one vertex. ...
A set A of vertices in an r-uniform hypergraph HH is covered in HH if there is some vertex u∉...
Fix an integer k ≥ 3. A k-uniform hypergraph is simple if every two edges share at most one vertex. ...
AbstractFix l⩾r⩾2. Let Hl+1(r) be the r-uniform hypergraph obtained from the complete graph Kl+1 by ...
Abstract. Let m∗(n) be the minimum number of edges in an n-uniform sim-ple hypergraph that is not tw...
A set A of vertices in an r-uniform hypergraph HH is covered in HH if there is some vertex u∉...
A set A of vertices in an r-uniform hypergraph H is covered inH if there is some vertex u∉ A such th...
AbstractThe following dual version of Turán's problem is considered: for a given r-uniform hypergrap...
AbstractThe upper chromatic number χ¯(H) of a hypergraph H=(X,E) is the maximum number k for which t...
Let F be a family of r-uniform hypergraphs. The chromatic threshold of F is the infimum of all non-n...