Submission: 2010, Aug 17
We give a short characteristic-free proof of the formula for the essential p-dimension of a group of multiplicative type first established in our preprint 363. We also give some new applications of this formula, in particular in prime characteristic.
2000 Mathematics Subject Classification: 20G15
Keywords and Phrases: Essential dimension, algebraic torus, group of multiplicative type, twisted finite group, lattice, Galois module
Full text: dvi.gz 29 k, dvi 81 k, ps.gz 836 k, pdf.gz 142 k, pdf 176 k.