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Research seminar in Discrete Mathematics
Research seminar in Discrete Mathematics
Odd-Ramsey Numbers of Hamilton Cycles
Odd-Ramsey Numbers of Hamilton Cycles
Organizers
Jie Ma
, Benjamin Sudakov
Speaker
Shagnik Das
Time
Tuesday, September 30, 2025 5:05 PM - 6:15 PM
Venue
Online
Online
Zoom 787 662 9899
(BIMSA)
Abstract
Introduced by Noga Alon in his work on graph codes, the odd-Ramsey number r(n,H) of a graph H is the smallest r such that there is an r-edge-colouring of K_n in which every copy of H has a colour that appears an odd number of times. In this talk, we continue the ongoing investigation of this graph parameter, determining the order of magnitude of the odd-Ramsey number of the Hamilton cycle C_n. Time permitting, we shall also discuss some initial results in a sparser setting, where we edge-colour Dirac graphs.
This is joint work with Simona Boyadzhiyska, Thomas Lesgourgues, and Kalina Petrova.
This is joint work with Simona Boyadzhiyska, Thomas Lesgourgues, and Kalina Petrova.
Speaker Intro
Shagnik Das earned his PhD in 2014, under the supervision of Benny Sudakov at UCLA. He then joined the Combinatorics and Graph Theory research group of Tibor Szabó at FU Berlin, first as a postdoc and later on his own grant. Since 2021, Shagnik has been an assistant professor at the National Taiwan University, where he works in extremal and probabilistic combinatorics.