Department of

# Mathematics

Seminar Calendar
for events the day of Tuesday, November 26, 2019.

.
events for the
events containing

Questions regarding events or the calendar should be directed to Tori Corkery.
     October 2019          November 2019          December 2019
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2  3  4  5                   1  2    1  2  3  4  5  6  7
6  7  8  9 10 11 12    3  4  5  6  7  8  9    8  9 10 11 12 13 14
13 14 15 16 17 18 19   10 11 12 13 14 15 16   15 16 17 18 19 20 21
20 21 22 23 24 25 26   17 18 19 20 21 22 23   22 23 24 25 26 27 28
27 28 29 30 31         24 25 26 27 28 29 30   29 30 31



Tuesday, November 26, 2019

2:00 pm in 243 Altgeld Hall,Tuesday, November 26, 2019

#### Nonrepetitive Graph Coloring

###### André Kündgen (CSU San Marcus Math)

Abstract: A repetition in an edge-colored graph is a path in which the sequence of colors in the first half of the path is identical to that in the second half. In 2002 Alon, Grytczuk, Haluszczak, and Riordan showed that every $k$-ary tree has a repetition-free edge-coloring with at most $4k$ colors. We present a simple procedure for obtaining repetition-free edge-colorings of $k$-ary trees with at most $3k+1$ colors. We will also discuss some related vertex-coloring questions.

This is joint work with Tonya Talbot.