### Graduate Student Seminar, 4:30 pm March 14, 2005; HH229

#### Speaker:

Corbett Redden
#### Title:

For what n is R^n a division algebra?
#### Abstract:

When n is 1, 2, 4, or 8, we have the reals, complexes, quaternions,
and octonions. These are the only values of n where this happens. We will
see how cohomology theories can provide a way to phrase and answer this
question by using something called the "Hopf invariant."

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contact Sara Miller