Department of

# Mathematics

Seminar Calendar
for events the day of Wednesday, January 30, 2019.

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events for the
events containing

Questions regarding events or the calendar should be directed to Tori Corkery.
    December 2018           January 2019          February 2019
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1          1  2  3  4  5                   1  2
2  3  4  5  6  7  8    6  7  8  9 10 11 12    3  4  5  6  7  8  9
9 10 11 12 13 14 15   13 14 15 16 17 18 19   10 11 12 13 14 15 16
16 17 18 19 20 21 22   20 21 22 23 24 25 26   17 18 19 20 21 22 23
23 24 25 26 27 28 29   27 28 29 30 31         24 25 26 27 28
30 31


Wednesday, January 30, 2019

3:00 pm in 341 Altgeld Hall,Wednesday, January 30, 2019

#### The cube problem and Schroeder-Bernstein problem for linear orders

###### Garret Ervin (Carnegie Mellon)

Abstract: We sketch proofs of solutions to two old problems posed by Sierpinski concerning products of linear orders. The first problem asks whether there exists a linear order $X$ that is isomorphic to its lexicographic cube but not to its square; the second, whether there are two non-isomorphic orders $Y$ and $Z$ that divide each other on both the left and right side. For other classes of structures, the corresponding questions are usually either both positive or both negative, but for linear orders the answers diverge: there is no such $X$, but there are such $Y$ and $Z$.

3:00 pm in 2 Illini Hall,Wednesday, January 30, 2019

#### Canceled

4:00 pm in 245 Altgeld Hall,Wednesday, January 30, 2019