Manfred Hartl. 
The nonabelian tensor square and Schur multiplicator of nilpotent groups 
of class 2. 

Abstract : The nonabelian tensor square and the Schur 
multiplicator are determined for arbitrary groups of class 2 in a
closed form. A functorial description is given in terms of a polynomial 
quotient of the integral group ring, as well as a more explicit
formula for finite groups which can be evaluated by matrix calculus. 
This is carried out for 2-generator groups. Also some
homotopical data of the suspended classifying space of class 2 groups 
are derived. The approach is based on the use of polynomial
maps and constructions in the sense of Passi.