Ron Aharoni, A strong version of the Caccetta-Haggkvist conjecture
Zoom ID: 869 4632 6610 (ibsdimag)The Caccetta-Haggkvist conjecture, one of the best known in graph theory, is that in a digraph with
10 events found.
Virtual Discrete Math Colloquium
Ken-ichi Kawarabayashi (河原林 健一), Toward Directed Graph Minor Theory
Zoom ID: 869 4632 6610 (ibsdimag)Graph Minor project by Robertson and Seymour is perhaps the deepest theory in Graph Theory. It gives a deep structural characterization of graphs without any graph
Bo Ning (宁博), Substructures and eigenvalues of graphs: Triangles and quadrilaterals
Zoom ID: 869 4632 6610 (ibsdimag)Our talk will mainly focus on the relationship between substructures and eigenvalues of graphs. We will briefly survey recent developments on a conjecture of Bollobás and Nikiforov and a classical …
James Davies, Separating polynomial
Zoom ID: 869 4632 6610 (ibsdimag)
We prove that there is a function
Manuel Lafond, Recognizing k-leaf powers in polynomial time, for constant k
Zoom ID: 869 4632 6610 (ibsdimag)A graph G is a k-leaf power if there exists a tree T whose leaf set is V(G), and such that uv is an edge if and only if the …
Fedor Fomin, Long cycles in graphs: Extremal Combinatorics meets Parameterized Algorithms
Zoom ID: 869 4632 6610 (ibsdimag)We examine algorithmic extensions of two classic results of extremal combinatorics. First, the theorem of Dirac from 1952 asserts that a 2-connected graph G with the minimum vertex degree d>1, …
Jean-Florent Raymond, Long induced paths in minor-closed graph classes and beyond
Zoom ID: 869 4632 6610 (ibsdimag)In 1982 Galvin, Rival, and Sands proved that in
Jakub Gajarský, Model Checking on Interpretations of Classes of Bounded Local Clique-Width
Zoom ID: 869 4632 6610 (ibsdimag)The first-order model checking problem for finite graphs asks, given a graph G and a first-order sentence
Michael Savery, Induced subgraphs of induced subgraphs of large chromatic number
Zoom ID: 869 4632 6610 (ibsdimag)We prove that for every graph F with at least one edge there are graphs H of arbitrarily large chromatic number and the same clique number as F such that …
Jan Kurkofka, Canonical Graph Decompositions via Coverings
Zoom ID: 869 4632 6610 (ibsdimag)We present a canonical way to decompose finite graphs into highly connected local parts. The decomposition depends only on an integer parameter whose choice sets the intended degree of locality. …