Symplectic structure in open string field theory. Part II. Sliding lump

A bstract We use a new formula for symplectic structure to compute the momentum of an analytic lump solution moving at constant velocity in Witten’s open string field theory. The computation gives a new way to determine the D-brane tension in string field theory. Using homotopy algebra technology, we prove that this tension must agree with the value implied by the on-shell action.