Yulai Ma, Pairwise disjoint perfect matchings in regular graphs

Room B332 IBS (기초과학연구원)

An r-graph is an r-regular graph in which every odd set of vertices is connected to its complement by at least r edges. A central question regarding r-graphs is determining the maximum number of pairwise disjoint perfect matchings they can contain. This talk explores how edge connectivity influences this parameter. For ${0 \leq \lambda \leq

Jun Gao (高峻), Phase transition of degenerate Turán problems in p-norms

Room B332 IBS (기초과학연구원)

For a positive real number p, the p-norm Gp of a graph G is the sum of the p-th powers of all vertex degrees. We study the maximum p-norm exp(n,F) of F-free graphs on n vertices, focusing on the case where F is a bipartite graph. It is natural to conjecture that for every bipartite

Joonkyung Lee (이준경), Counting homomorphisms in antiferromagnetic graphs via Lorentzian polynomials

Room B332 IBS (기초과학연구원)

An edge-weighted graph G, possibly with loops, is said to be antiferromagnetic if it has nonnegative weights and at most one positive eigenvalue, counting multiplicities. The number of graph homomorphisms from a graph H to an antiferromagnetic graph G generalises various important parameters in graph theory, including the number of independent sets and proper vertex

Huy Tuan Pham, Random Cayley graphs and Additive combinatorics without groups

Room B332 IBS (기초과학연구원)

A major goal of additive combinatorics is to understand the structures of subsets A of an abelian group G which has a small doubling K = |A+A|/|A|. Freiman's celebrated theorem first provided a structural characterization of sets with small doubling over the integers, and subsequently Ruzsa in 1999 proved an analog for abelian groups with

Tony Huynh, The Peaceable Queens Problem

Room B332 IBS (기초과학연구원)

The peaceable queens problem asks to determine the maximum number a(n) such that there is a placement of a(n) white queens and a(n) black queens on an n×n chessboard so that no queen can capture any queen of the opposite color. We consider the peaceable queens problem and its variant on the toroidal

Laure Morelle, Bounded size modifications in time 2poly(k)n2

Room B332 IBS (기초과학연구원)

A replacement action is a function L that maps each graph to a collection of subgraphs of smaller size. Given a graph class H, we consider a general family of graph modification problems, called "L-Replacement to H", where the input is a graph G and the question is whether it is

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 k, every graph contains k vertex-disjoint cycles or a set of O(klogk) vertices which intersects every cycle of G.

Sepehr Hajebi, TBA

Room B332 IBS (기초과학연구원)
IBS 이산수학그룹 Discrete Mathematics Group
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IBS Discrete Mathematics Group (DIMAG)
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