Ken-ichi Kawarabayashi (河原林 健一), Toward Directed Graph Minor Theory
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 $H$ as a minor. …
10 events found.
Seminars and Colloquiums
Events
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Zoom ID: 869 4632 6610 (ibsdimag)
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O-joung Kwon (권오정), Reduced bandwidth: a qualitative strengthening of twin-width in minor-closed classes (and beyond)
Room B232 IBS (기초과학연구원)In a reduction sequence of a graph, vertices are successively identified until the graph has one vertex. At each step, when identifying $u$ and $v$, each edge incident to exactly …
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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 …
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Pascal Gollin, A unified Erdős-Pósa theorem for cycles in graphs labelled by multiple abelian groups
Room B232 IBS (기초과학연구원)Erdős and Pósa proved in 1965 that there is a duality between the maximum size of a packing of cycles and the minimum size of a vertex set hitting all …
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James Davies, Separating polynomial $\chi$-boundedness from $\chi$-boundedness
Zoom ID: 869 4632 6610 (ibsdimag)We prove that there is a function $f : \mathbb{N} \to \mathbb{N}$ such that for every function $g : \mathbb{N} \to \mathbb{N} \cup \{\infty\}$ with $g(1)=1$ and $g \ge f$, …
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Jinha Kim (김진하), Independent domination of graphs with bounded maximum degree
Room B232 IBS (기초과학연구원)An independent dominating set of a graph, also known as a maximal independent set, is a set $S$ of pairwise non-adjacent vertices such that every vertex not in $S$ is …
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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 …
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Donggyu Kim (김동규), A stronger version of Tutte’s wheel theorem for vertex-minors
Room B232 IBS (기초과학연구원)Tutte (1961) proved that every simple $3$-connected graph $G$ has an edge $e$ such that $G \setminus e$ or $G / e$ is simple $3$-connected, unless $G$ is isomorphic to …
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Sang-il Oum (엄상일), Obstructions for matroids of path-width at most k and graphs of linear rank-width at most k
Room B232 IBS (기초과학연구원)Every minor-closed class of matroids of bounded branch-width can be characterized by a minimal list of excluded minors, but unlike graphs, this list could be infinite in general. However, for …
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Kevin Hendrey, A unified Erdős-Pósa theorem for cycles in graphs labelled by multiple abelian groups (revisited)
Room B232 IBS (기초과학연구원)This talk follows on from the recent talk of Pascal Gollin in this seminar series, but will aim to be accessible for newcomers. Erdős and Pósa proved in 1965 that …