We write down the Yang-Mills partition function and the average Wilson loop
in terms of local gauge-invariant variables bring the six components of th
e metric tensor of dual space. The Wilson loop becomes the trace of the par
allel transporter in curved space, else called the gravitational holonomy.
We show that the external coordinates mapping the 3d curved space into a fl
at 6d space play the role of glueball fields, and there is a natural mechan
ism for the mass gap generation. (C) 2000 Elsevier Science B.V. All rights
reserved.