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# Quantum Cohomology in the Real World

### Frank Sottile

University of Massachusetts, Amherst

###
Thursday, November 30, 2000

102 Bradley Hall, 4 pm

Tea 3:30 pm, Math Lounge

**Abstract: **
In the last (20th) century, two different groups of scientists were
led to exactly the same question in pure mathematics, a problem of
counting certain rational curves on a Grassmannian. The work of one
group, theoretical physicists, spawned important mathematical
activity, including quantum cohomology. This story of mathematics
inspired by physics is well-known, even though the physical motivation
remains obscure to many mathematicians.

The other group of
scientists were engineers working in systems theory, specifically on
the problem of dynamic feedback control of linear systems. While
their story is less-known, their motivation for studying curves on
Grassmannians are straightforward and their work leads to a very
concrete understanding of this problem.

In this talk, I will make
the second story better-known, explaining how engineers were led to
study spaces of curves on Grassmannians and some further mathematics
inspired by their work.

This talk will be accessible to graduate students.