Invitation to higher local fields, Part I, section 1: Higher dimensional local fields
arXiv:math/0012132
Abstract
Basic concepts of higher local fields and topologies on their additive and multiplicative groups are introduced.
For introduction and notation, see math.NT/0012131 . Published by Geometry and Topology Monographs at http://www.maths.warwick.ac.uk/gt/GTMon3/m3-I-1.abs.html