SUBGROUPS OF INERTIA GROUPS ARISING FROM ABELIAN-VARIETIES

Given an abelian variety over a field with a discrete valuation, Groth endieck defined a certain open normal subgroup of the absolute inertia group. This subgroup encodes information on the extensions over which the abelian variety acquires semistable reduction. We study this subg roup, and use it to obtain information on the extensions over which th e abelian variety acquires semistable reduction. (C) 1998 Academic Pre ss.