CMS Coxeter-James Lecture / Conférence Coxeter-James de la SMC
- KAI BEHREND, University of British Columbia
Quantum Cohomology and the virtual fundamental class
or ``how to count properly''
Motivated by the desire to have beautiful formulas, mathematicians have
realized time and again that it is necessary to change the meaning of
the ``number of solutions'' to a problem. The simplest case is maybe
the introduction of the complex numbers in order for the theorem ``any
quadratic equation has two solutions'' to become true. The introduction
of Gromov-Witten invariants (i.e., quantum cohomology) into
algebraic geometry can be understood as another step in this program.
This talk is meant to be a somewhat leisurly introduction to some of
the ideas involved in this long story.