Florian Gut and Attila Joó, Large vertex-flames in uncountable digraphs
Zoom ID: 869 4632 6610 (ibsdimag)The local connectivity
10 events found.
Suil O (오수일), Eigenvalues and [a, b]-factors in regular graphs
Room B232 IBS (기초과학연구원)For positive integers,
Jaehoon Kim (김재훈),
Room B232
IBS (기초과학연구원)
For a graph
Stefan Weltge, Integer programs with bounded subdeterminants and two nonzeros per row
Room B232 IBS (기초과학연구원)We give a strongly polynomial-time algorithm for integer linear programs defined by integer coefficient matrices whose subdeterminants are bounded by a constant and that contain at most two nonzero entries in each row. The core of our approach is the first polynomial-time algorithm for the weighted stable set problem on graphs that do not contain …
Semin Yoo (유세민), Combinatorics of Euclidean spaces over finite fields
Room B232 IBS (기초과학연구원)Euiwoong Lee (이의웅), The Karger-Stein algorithm is optimal for k-cut
Room B232 IBS (기초과학연구원)In the k-cut problem, we are given an edge-weighted graph and want to find the least-weight set of edges whose deletion breaks the graph into k connected components. It is easy to see that the elegant randomized contraction algorithm of Karger and Stein for global mincut (k=2) can be naturally extended for general k with …
Maria Chudnovsky, Induced subgraphs and tree decompositions
Zoom ID: 869 4632 6610 (ibsdimag)Tree decompositions are a powerful tool in structural graph theory; they are traditionally used in the context of forbidden graph minors. Connecting tree decompositions and forbidden induced subgraphs has until recently remained out of reach. Tree decompositions are closely related to the existence of "laminar collections of separations" in a graph, which roughly means that …
Duksang Lee (이덕상), Intertwining connectivities for vertex-minors and pivot-minors
Room B232 IBS (기초과학연구원)We show that for pairs (Q,R) and (S,T) of disjoint subsets of vertices of a graph G, if G is sufficiently large, then there exists a vertex v in V(G)−(Q∪R∪S∪T) such that there are two ways to reduce G by a vertex-minor operation while preserving the connectivity between Q and R and the connectivity between S …
Linda Cook, Two results on graphs with holes of restricted lengths
Room B232 IBS (기초과학연구원)We call an induced cycle of length at least four a hole. The parity of a hole is the parity of its length. Forbidding holes of certain types in a graph has deep structural implications. In 2006, Chudnovksy, Seymour, Robertson, and Thomas famously proved that a graph is perfect if and only if it does not contain …
Petr Hliněný, Twin-width is linear in the poset width
Zoom ID: 869 4632 6610 (ibsdimag)Twin-width is a new parameter informally measuring how diverse are the neighbourhoods of the graph vertices, and it extends also to other binary relational structures, e.g. to digraphs and posets. It was introduced quite recently, in 2020 by Bonnet, Kim, Thomassé, and Watrigant. One of the core results of these authors is that FO model checking on graph classes of …