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SUPERGRAVITY P. van NIEUWENHUIZEN To Joel Scherk 0370 ...

SUPERGRAVITY P. van NIEUWENHUIZEN To Joel Scherk 0370 ...

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P. <strong>van</strong> Nieuwenhuizen, Supergravity 367One thus finds= (o’, il)’ 48 and (U,,)AB = (u, —iI)~ 8. (6)Since (cr,. )AB are Hermitian (which means antiHermitian for s = 4 in our conventions), lowering itsindices to (O,,)c~one finds the transpose (or complex conjugate) of (0,L)AB, namelyNote that(u~)co (cr” )‘4~ ~ = U~Dc. (7)48(o~”)nc= 0”~c (no sum over it). (8)(cr,.)’Raising of the index ~ is done by 0”~= (+, +, +, +). with ,a, ii = 1,4 in our conventions.The matrices (o~J’~and (o~,.)’48are invariant tensors of SL(2, C). That is to say that, for example,(cr~’~48)’ = L’4cL~L~,.u~’~ = U~~AE (9)One can thus express tensors with Lorentz indices into tensors with spinor indices as followsT~..:-* T~: (U,. rM(O-”)RRT~..:. (10)Often one writes TRR ~ as TRSRS, but one should not confuse this with TSRRS.The connections (cr,.~8 satisfy the following completeness relations~CD D C(o,,)An(o ) —20 A0 g(cr,. )AB(U~)cD = 2 A~BD= (ci,,)BA(O~)Dc (see (7))(U,.)AB(U~~)BA= 20~= (u,.)AB(ci~)~~ = (0,.)~8(0.o)~4B(cr,,Y~ 8(cr~)’~ = 2 ~ B1~~ = (cr,,)~(o.1~f The reason we defined ~~B= —1 for A = 1, E = 2, is that with this definition no minus signs occur inthese relations. One can use them to go back and forth:r’ I AR CI)i,r,,,. — CT,. FABCD(12)FARCD = F,.,XJ~AE1Y = ~(11)where FBADC= F,.,.(o~”)8’4(o-”)DC.In fact, quite generally VAJ3 = VEA, as one easily proves usingUMAB = ciBA and o~~4B=0RA (13)An antisymmetric tensor GAB = — GRA is clearly proportional to EAR. Hence, for an antisymmetric

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