Free Fields Equations For Space-Time Algebras With Tensorial Momentum

Free field equations, with various spins, for space-time algebras with second-rank tensor (instead of usual vector) momentum are constructed. Similar algebras are appearing in superstring/M theories. The most attention is payed to the gauge invariance properties, particularly the spin two equations with gauge invariance are constructed for dimensions 2+2 and 2+4 and connection to Einstein equation and diffeomorphism invariance is established.