Department of

# Mathematics

Seminar Calendar
for events the day of Friday, April 24, 2020.

.
events for the
events containing

Questions regarding events or the calendar should be directed to Tori Corkery.
      March 2020             April 2020              May 2020
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  6  7             1  2  3  4                   1  2
8  9 10 11 12 13 14    5  6  7  8  9 10 11    3  4  5  6  7  8  9
15 16 17 18 19 20 21   12 13 14 15 16 17 18   10 11 12 13 14 15 16
22 23 24 25 26 27 28   19 20 21 22 23 24 25   17 18 19 20 21 22 23
29 30 31               26 27 28 29 30         24 25 26 27 28 29 30
31


Friday, April 24, 2020

4:00 pm in Zoom Meeting,Friday, April 24, 2020

#### The Arithmetic of Quadratic Fields

###### Patrick Allen (UIUC Math)

Abstract: It is often said that the prime numbers are the building blocks of the integers, the precise statement of which is the fundamental theorem of arithmetic: any integer greater than one can be factored uniquely as a product of prime numbers. What if we move beyond the integers? The simplest cases to consider are the analogues of the integers in what are called quadratic fields, which are number systems obtained from adding to the rational numbers the square root of some fixed integer. Whether or not these quadratic integers satisfy the analogue of the fundamental theorem of arithmetic turns out to be very subtle and both what is known and what is not known are rather surprising. Please email drthoma2@illinois.edu for Zoom link.