Department of

# Mathematics

Seminar Calendar
for events the day of Tuesday, September 22, 2020.

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events for the
events containing

Questions regarding events or the calendar should be directed to Tori Corkery.
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Tuesday, September 22, 2020

11:00 am in On-line (zoom),Tuesday, September 22, 2020

#### TBA

###### Jake Chinis (McGill math)

2:00 pm in Zoom,Tuesday, September 22, 2020

#### Tilings in vertex ordered graphs

###### Lina Li (University of Waterloo)

Abstract: Over recent years, there has been much interest in both Turan and Ramsey properties of vertex ordered graphs. In this talk, we initiate the study of embedding spanning structures into vertex ordered graphs. In particular, we introduce a general framework for approaching the problem of determining the minimum degree threshold for forcing a perfect $H$-tiling in an ordered graph. (In the unordered graph setting, this problem was resolved by Kuhn and Osthus in 2009.) We use our general framework to resolve the perfect $H$-tiling problem for all ordered graphs $H$ of interval chromatic number $2$. Already in this restricted setting the class of extremal examples is richer than in the unordered graph problem. This is joint work with Jozsef Balogh and Andrew Treglown.