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«  Ramsey and Turán Numbers of Sparse Hypergraphs

Ramsey and Turán Numbers of Sparse Hypergraphs

December 02, 2024, 2:00 PM - 3:00 PM

Location:

Conference Room 705

Rutgers University

Hill Center

110 Frelinghuysen Rd

Piscataway, NJ 08854

Jonathan Tidor, Stanford University

The degeneracy of a graph is a measure of sparseness that gives important information about its Turán- and Ramsey-type properties. I will talk about the extension of this problem to hypergraphs. The typical notion of hypergraph degeneracy does not give any information about either the Ramsey or Turán numbers of hypergraphs; instead we define a notion called skeletal degeneracy. We prove the hypergraph generalization of the Burr--ErdÅ‘s conjecture: hypergraphs of bounded skeletal degeneracy have Ramsey number linear in their number of vertices. Furthermore, we give good bounds on the Turán exponent of partite hypergraphs in terms of their skeletal degeneracy.

Based on joint work with Jacob Fox, Maya Sankar, Michael Simkin, and Yunkun Zhou.