Topology/Geometry Qualifying Exam
Study Group, Summer, 2005
Here you'll find general information about the
Topology/Geometry Qualifying exam study group for the August 2005
exam. To contact me, you can
email me at cbtruman (at math etc. etc.) or
stop by my office, 4410 where I can be found
approximately whenever I happen to come in (which tends to be every
weekday between about 9:00 a.m. and 5:00 p.m.). I'm pretty easy to
find, though your mileage may vary.
We are meeting Mondays in room 0104 from 3:00-4:00ish and
Thursdays in room 1308 from 11:00-12:00ish.
Generally, during the sessions we will work on
old qual problems. This tends to work as follows: I pick
out a problem, and then pick some poor sucker to work it out on the
board, while everyone else in the room nit-picks (or provides hints,
depending on any given person's personality and mood). If necessary,
I will work some problems on the board, or try to clarify things which
I think might be fuzzy. However, when I work problems, I would
generally like to give a general outline and leave the details to
everyone else. If you would prefer to be left out of the
sucker-picking process (for working problems on the board), just let me
know, though I will warn you that doing the problems is the best way
to learn, especially doing them for other people to critique. On the
other hand, if you'd like to work on the board more frequently than you find
you are being chosen, I can try to do that as well.
The old quals can be found here.
Since some of us have
done these quals before, I've also made a couple of practice quals, and
I've tried to make them about on par with the old quals. You can get those
here (in pdf format; if you want another format you'll have to let me
know):
The qual syllabus is posted here.
I have found that it is useful to know a couple of other things too
(that aren't on the qual syllabus). Generally, it is my understanding
that you can use things not on the syllabus as long as it doesn't
completely trivialize the problem (i.e. as long as the problem isn't
just a restatement or special case of the theorem), but if you use
something outside the qual syllabus, you'd better provide a very clear
statement of the theorem and why it applies.
If I think of more I will add them.
- Cellular Approximation theorem (Bredon, Chapter IV, section
11).
- Tubular Neighborhood theorem (Bredon, Chapter II, section
11). (Updated 04/07/04: Since I wrote this, I've reconsidered due to the fact
that understanding this theorem requires more knowledge of vector
bundles than is really necessary for the qual. So maybe this isn't so
useful after all unless you want to learn a little extra about vector
bundles...)
- Whitehead and Hurewicz theorems (only occasionally, and then only
to speed things along...Bredon, Chapter VII, sections 10 and 11).
- Elementary Morse theory (only very occasionally, and never really
for a super important part of the problem, but I think it helps...see
Milnor's book "Morse Theory").
While I find many of the problems are poorly phrased, I think
mostly everyone can figure out what was meant. However, problem 6 on
the August, 2002 qual had some very important things left out of it,
so it isn't as clear what is intended. If I find any more like this,
or if anyone would like any particular problem clarified like this, I
will post them here:
I also have other general gripes about the qual;
for example, connected sum problems come up often,
and every time the writer feels it necessary to provide a definition,
and I have never seen two that were quite the same. They generally
amount to the same thing (although I can think of one in particular,
August 2001, that doesn't quite work; try using the given definition with the
complements of single points in Sn). My
recommendation is for you to figure out for yourself what a connected
sum is before you take the qual. Then when you see their definition,
simply skim it to make sure that they really are talking about the
same thing, and proceed to use your own definition. Another thing
which can cause headaches is that sometimes important adjectives (like
compact or orientable or sometimes smooth) can be left out in the
description of a manifold. Sometimes the person who wrote the problem
is not aware that, using Bredon's definitions, a
manifold-with-boundary is not, strictly speaking, a manifold. Most of
the time one can figure out what is meant. If you can't, it is
important to ask the proctor, who can go ask a professor. These
mistakes are amusing to people who look at the quals later to try to
work over them, but I can personally recall being on the fourth page
of a problem before I was told that the manifolds in
question were actually compact (August 2001, problem 6). It was
somewhat less than amusing then (although it was a relief, since that
was the easiest of the three cases I had been considering). One of
my favorite mistakes was a problem (August 2002, problem 3)
that asked you to assume that X was path-connected, then asked
in part (a) to show that X was path-connected. The funny thing is,
if you omitted the given condition (that X was
path-connected) you no longer had enough information to prove it.
Another problem (January 2002, number 1) describes a manifold that the astute
reader can prove does not exist (the Euler characteristic of a
4n+2-dimensional manifold must be even - see problem 5, January
2003; I have been told that the problem was do-able otherwise, and
that full marks were given to anyone who wrote that the manifold in
question did not exist). Some of these have been corrected in the
versions that they hand out in the grad office, some haven't. Your
best bet when practicing is to ask around.