Subgroups, of Chevalley groups over a locally finite field, defined by a family of additive subgroups.

It is proved that every elementary carpet of nonzero additive subgroups which is associated with a Chevalley group of a Lie rank exceeding one over a locally finite field coincides, up to conjugation by a diagonal element, with a carpetwhose additive subgroups are equal to some chosen subfield of the ground field. A similar result is obtained for a full matrix carpet (a full net). [ABSTRACT FROM AUTHOR]