  Experiment shows that the top quark is far heavier than the other elementary
fermions. This finding has stimulated research on theories of electroweak and
flavor symmetry breaking that include physics beyond the standard model.
Efforts to accommodate a heavy top quark within existing frameworks have
revealed constraints on model-building. Other investigations have started from
the premise that a large top quark mass could signal a qualitative difference
between the top quark and other fermions, perhaps in the form of new
interactions peculiar to the top quark. Such new dynamics may also help answer
existing questions about electroweak and flavor physics. This talk explores the
implications of the heavy top quark in the context of weakly-coupled (e.g.
SUSY) and strongly-coupled (e.g. technicolor) theories of electroweak symmetry
breaking.
