A Note on Stress-Energy Tensor and Variational Principle for Null Strings

A straightforward application of the variational principle to null strings meets difficulties since string’s world-sheets are degenerate. It is known that in this case can be formulated with help two-vector density on string world-sheet which plays a role Lagrange multipliers. shown recently suggested stress-energy tensor derived by variation over background metric action used describe tensionless limit theory. One multipliers related energy string.