BMN operators and string field theory

Abstract We extract from gauge theoretical calculations the matrix elements of the SYM dilatation operator. By the BMN correspondence this should coincide with the 3-string vertex of light cone string field theory in the pp-wave background. We find a mild but important discrepancy with the SFT results. If the modified O ( g 2 ) matrix elements are used, the O ( g 2 2 ) anomalous dimensions are exactly reproduced without the need for a contact interaction in the single-string sector.