Colloquium: Mathematical Surgery (Friday)

Come see your fellow undergrad Alec Leng (’21) give a talk on knot theory this Friday afternoon. See below for details and Alec’s summary of the talk.

Since this is a new kind of event, please take 10 seconds to tell me if you are thinking about attending! I want to make sure we have plenty of food.
Who: Alec Leng (’21)
What? An Introduction to (Mathematical) Surgery
When? Friday, April 5, 4:30-5:15 pm
Where? Fine 214
Food? Jules Pizza (pls email me if you have suggestions for toppings)
Consider a topological circle:


Now let’s cut out part of it:

And stick it back in!

And now we have two circles! Stated a bit more technically, we’ve cut out a copy of S^0xD^1 from S^1, and then glued it back in a different way to produce two S^1s. This process is called surgery, and one can do it on general manifolds as well; in particular, it lets us generate a lot of 3 dimensional manifolds! Come to this talk to see more (hopefully somewhat pretty) pictures, more examples of surgery, and hear about why it’s such a vital tool in geometric topology.
I’ll be assuming some basic topology (e.g. intuitive definition of a manifold, idea of what a homeomorphism is, and ideally being able to visualize S^3 as 3 dimensional Eucildean space but with an extra point, though don’t worry if you can’t— I’ll talk more about this at the beginning of my talk).

Hope to see you there!!
Alice and Gary, co-advising chairs
In case the RSVP link didn’t work: