Jaehoon Kim (김재훈), $K_{r+1}$-saturated graphs with small spectral radius
For a graph $H$, a graph $G$ is $H$-saturated if $G$ does not contain $H$ as a subgraph but for any $e\in E(\overline G)$, $G+e$ contains $H$. In this note, we prove …
10 events found.
Discrete Math Seminar
Events
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Room B232 IBS (기초과학연구원)
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Semin Yoo (유세민), Combinatorics of Euclidean spaces over finite fields
Room B232 IBS (기초과학연구원)$q$-analogues of quantities in mathematics involve perturbations of classical quantities using the parameter $q$, and revert to the original quantities when $q$ goes $1$. An important example is the $q$-analogues …
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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 …
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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 …
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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 …
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Eun Jung Kim (김은정), A Constant-factor Approximation for Weighted Bond Cover
Room B232 IBS (기초과학연구원)The Weighted $\mathcal F$-Vertex Deletion for a class $\mathcal F$ of graphs asks, given a weighted graph $G$, for a minimum weight vertex set $S$ such that $G-S\in\mathcal F$. The …
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Cheolwon Heo (허철원), Representations of even-cycle matroids
Room B232 IBS (기초과학연구원)A signed graph is a pair $(G,\Sigma)$ where $G$ is a graph and $\Sigma$ is a subset of edges of $G$. A cycle $C$ of $G$ is a subset of …
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Dabeen Lee (이다빈), Mixing sets, submodularity, and chance-constrained optimization
Room B232 IBS (기초과학연구원)A particularly important substructure in modeling joint linear chance-constrained programs with random right-hand sides and finite sample space is the intersection of mixing sets with common binary variables (and possibly …
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Kevin Hendrey, Extremal functions for sparse minors
Room B232 IBS (기초과학연구원)The extremal function $c(H)$ of a graph $H$ is the supremum of densities of graphs not containing $H$ as a minor, where the density of a graph is the ratio …
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Eunjin Oh (오은진), Feedback Vertex Set on Geometric Intersection Graphs
Room B232 IBS (기초과학연구원)I am going to present an algorithm for computing a feedback vertex set of a unit disk graph of size k, if it exists, which runs in time $2^{O(\sqrt{k})}(n + …