Colloquium
3:30 p.m., Friday
Math 100
Akbar Rhemtulla
Department of Mathematical Sciences
University of Alberta
Expressing Elements of the Commutator Subgroup of a Group
as a Product of Least Number of Commutators
The first part of the talk is a survey of present status of the
general question: For which groups G generated by d generators is
there a bound b = b(d), such that every element in the commutator subgroup [G,G] is expressible as a product of b commutators? This question remains open for finite groups G. It is also open in the
case when G is solvable. The solution when G is finite and soluble
was obtained in 1999 by D. Segal.
In the second part we turn our attention to the free group F=F(x, y)
and give an algorithm and an elementary proof to show that ([x,y])^n
can be written as a product of [n/2]+1 commutators and this is the
best possible. Here [n/2] is the greatest integer not exceeding n/2.
Other related results will also be discussed.
