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

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

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208 P. <strong>van</strong> Nieuwenhuizen. SupergrarirvS2’( 2) = ~1. ~‘ mncd (D,,e~)e ~ 800cdD ~ tm~1~ mn (3,.e,. — 0,,e,. w,, er,..Note that the derivative D,, always contains only the spin connection, but not a connection F~,..As aresult, D,.e’ is non-zero.Next we vary the spin connection in the Rarita—Schwinger action.82’312 = ‘ ~“~~(tl/yyut/i) (80)cd) (4)Since l/i,.y5y~u~dt//,, can be written as vector terms and axial vector terms by decomposing Y~O~cd(seeappendix A)l/i,.757,ArcdtIJ,, = ~tlJ,.yS(e~~yd — ed~yC)llI,,+ ~et~,, bcdml/i,.ymt/,,, (5)and since l/’,.ylydt/i,, is symmetric in p~and o- while ~,.y’~i/i,, is antisymmetric (see appendix C), we find82’3/2 = — 8 1. ~“ ncdm (~ym~, )en ~ cd (6)Comparison of eqs. (6) and (3) thus yieldstm,, — D~etm,.= ~- (çj~ytmç/i) (7)D,.efor the field equation of the spin connection. Due to our rewriting of 2’2 as in eq. (1), one can easilyread off this result, since in eq. (6) and in eq. (1) the two -symbols are in common.With the first tetrad postulate (which is really a definition of w(e)) that 0,.em~+w,.m~(e)—= 0, one can proceed to solve from eq. (7) the spin connection ~ itself. <strong>To</strong> this purpose itis useful to introduce the contorsion tensor K,.””’ byma — mtm( ~+ ma(0,. —00,. ~, K,.w,.rn~(e) = ~e~”(8,.e~~ — 8~e~,.) — ~ (8,.emv — Opem,.) — ~em”en~(8~e~,, — 8,,e,~,)e’,.. (8)With (7) and the first tetrad postulate, one finds0,.etm~+ wtm(e) (,~ v) 0K2- 9— Kr,,,,. = ~ tli,,y~tl/~. ( )This equation is solved in the same way as one solves in general relativity for F”,.~(g)in terms of ~that is to say, one considers the identity— K~~,.)+~ — iç,.m)+ ~ — Içptm) = 2K,.,,,~. (10)

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