We investigate the relation between the subleading soft graviton theorem and
asymptotic symmetries in gravity in even dimensions higher than four. After
rewriting the subleading soft graviton theorem as a Ward identity, we argue
that the charges of such identity generate Diff(S2m). In order to show
that, we propose suitable commutation relation among certain components of the
metric fields. As a result, all Diff(S2m) transformations are symmetries
of gravitational scattering.Comment: 17 pages, 1 figure; v2 added reference