Jang Soo Kim (김장수), Longest elements in a semigroup of functions and Slater indices
Room B332 IBS (기초과학연구원)The group
10 events found.
Seminars and Colloquiums
Jungho Ahn (안정호), A coarse Erdős-Pósa theorem for constrained cycles
Room B332 IBS (기초과학연구원)An induced packing of cycles in a graph is a set of vertex-disjoint cycles such that the graph has no edge between distinct cycles of the set. The classic Erdős-Pósa theorem shows that for every positive integer
O-joung Kwon (권오정), Erdős-Pósa property of A-paths in unoriented group-labelled graphs
Room B332 IBS (기초과학연구원)A family
Sepehr Hajebi, The pathwidth theorem for induced subgraphs
Room B332 IBS (기초과학연구원)We present a full characterization of the unavoidable induced subgraphs of graphs with large pathwidth. This consists of two results. The first result says that for every forest H, every graph of sufficiently large pathwidth contains either a large complete subgraph, a large complete bipartite induced minor, or an induced minor isomorphic to H. The …
Irene Muzi, An elementary bound for Younger’s conjecture
Room B332 IBS (기초과학연구원)In 1996, Reed, Robertson, Seymour and Thomas proved Younger's Conjecture, which states that for all directed graphs D, there exists a function f such that if D does not contain k disjoint cycles, D contains a feedback vertex set, i.e. a subset of vertices whose deletion renders the graph acyclic, of size bounded by f(k). …
Johannes Carmesin, Open problems in graph theory
Room B332 IBS (기초과학연구원)Since the proof of the graph minor structure theorem by Robertson and Seymour in 2004, its underlying ideas have found applications in a much broader range of settings than their original context. They have driven profound progress in areas such as vertex minors, pivot minors, matroids, directed graphs, and 2-dimensional simplicial complexes. In this talk, …
Michał Seweryn, Dimension and standard examples in planar posets
Room B332 IBS (기초과학연구원)The dimension of a poset is the least integer
Hyunwoo Lee (이현우), Reconstructing hypergraph matching polynomials
Room B332 IBS (기초과학연구원)By utilizing the recently developed hypergraph analogue of Godsil's identity by the second author, we prove that for all
Marcelo Garlet Milani, Cycles of Well-Linked Sets and an Elementary Bound for the Directed Grid Theorem
Room B332 IBS (기초과학연구원)In 2015, Kawarabayashi and Kreutzer proved the directed grid theorem. The theorem states the existence of a function f such that every digraph of directed tree-width f(k) contains a cylindrical grid of order k as a butterfly minor, but the given function grows non-elementarily with the size of the grid minor. We present an alternative …
Daniel McGinnis, A necessary and sufficient condition for
Room B332
IBS (기초과학연구원)
We solve a long-standing open problem posed by Goodman and Pollack in 1988 by establishing a necessary and sufficient condition for a finite family of convex sets in