István Tomon, Ramsey properties of semilinear graphs
A graph $G$ is semilinear of bounded complexity if the vertices of $G$ are elements of $\mathbb{R}^{d}$, and the edges of $G$ are defined by the sign patterns of $t$ …
10 events found.
Seminars and Colloquiums
Events
-
-
Zoom ID: 869 4632 6610 (ibsdimag)
-
Sang-il Oum (엄상일), What is an isotropic system?
Room B232 IBS (기초과학연구원)Bouchet introduced isotropic systems in 1983 unifying some combinatorial features of binary matroids and 4-regular graphs. The concept of isotropic system is a useful tool to study vertex-minors of graphs …
-
Reinhard Diestel, Tangles of set separations: a novel clustering method and type recognition in machine learning
Zoom ID: 869 4632 6610 (ibsdimag)Traditional clustering identifies groups of objects that share certain qualities. Tangles do the converse: they identify groups of qualities that typically occur together. They can thereby discover, relate, and structure …
-
Jungho Ahn (안정호), Well-partitioned chordal graphs with the obstruction set and applications
Room B232 IBS (기초과학연구원)We introduce a new subclass of chordal graphs that generalizes split graphs, which we call well-partitioned chordal graphs. Split graphs are graphs that admit a partition of the vertex set …
-
-
Raul Lopes, Adapting the Directed Grid Theorem into an FPT Algorithm
Zoom ID: 869 4632 6610 (ibsdimag)The Grid Theorem of Robertson and Seymour is one of the most important tools in the field of structural graph theory, finding numerous applications in the design of algorithms for …
-
Hong Liu, Sublinear expander and embeddings sparse graphs
ZoomA notion of sublinear expander has played a central role in the resolutions of a couple of long-standing conjectures in embedding problems in graph theory, including e.g. the odd cycle …
-
Mark Siggers, The list switch homomorphism problem for signed graphs
Room B232 IBS (기초과학연구원)A signed graph is a graph in which each edge has a positive or negative sign. Calling two graphs switch equivalent if one can get from one to the other …
-
Johannes Carmesin, A Whitney type theorem for surfaces: characterising graphs with locally planar embeddings
Zoom ID: 869 4632 6610 (ibsdimag)Given a graph, how do we construct a surface so that the graph embeds in that surface in an optimal way? Thomassen showed that for minimum genus as optimality criterion, …
-
Pascal Gollin, Enlarging vertex-flames in countable digraphs
Room B232 IBS (기초과학연구원)A rooted digraph is a vertex-flame if for every vertex v there is a set of internally disjoint directed paths from the root to v whose set of terminal edges covers all …
-
Benjamin Bumpus, Directed branch-width: A directed analogue of tree-width
Zoom ID: 869 4632 6610 (ibsdimag)Many problems that are NP-hard in general become tractable on `structurally recursive’ graph classes. For example, consider classes of bounded tree- or clique-width. Since the 1990s, many directed analogues of …