Roland Lötscher, Mark MacDonald, Aurel Meyer and Zinovy Reichstein: Essential p-dimension of algebraic tori

Submission: 2009, Oct 28

The essential dimension is a numerical invariant of an algebraic group G which may be thought of as a measure of complexity of G-torsors over fields. A recent theorem of N. Karpenko and A. Merkurjev gives a simple formula for the essential dimension of a finite p-group. We obtain similar formulas for the essential p-dimension of a broader class of groups, which includes all algebraic tori.

2000 Mathematics Subject Classification: 20G15

Keywords and Phrases: Essential dimension, algebraic torus, twisted finite group, lattice

Full text: dvi.gz 61 k, dvi 136 k, ps.gz 859 k, pdf.gz 277 k, pdf 310 k.

Server Home Page