12.07.2015 Views

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

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

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

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

P. <strong>van</strong> Nieuwenhuizen, Supergravity 301Consider now the {Q, Q} anticommutator acting on em~.Since only physical fields appear at allstages, and physical fields have never a nonzero 8’ transformation law, the only way the theory managesto make P-gauges an invariance, is by requiring that R(P) in (5) <strong>van</strong>ishes. ThusF~I \~I \lm _~~tA BC_1-~oQ~el),uQ~E2)Je ~L~°PV BC 1E2 —2 2Y ~1m(F) = 0, this is according to (5) a sum of a general coordinate transformation plus otherand localsince symmetries. R This explains also why in the superconformal algebra the parameters in the {Q, Q}anticommutator are all of the form ë2y~’eitimes the gauge field h~.The other constraints play a similar role. For example, in the {Q, 0) anticommutator on ~ one findsnow an unphysical field, namely ~ due to ~ = D~ .Thus now the theory has a choice: eitherchoosing an appropriate ô’w (which again leads to the constraint R(P) 0), or by putting R(Q) = 0 as aconstraint. The latter choice is not possible since no field can be solved from R(Q) = 0, while the formerchoice is the correct one:[~fri), ôo 2)]~= ië y’~’ R’~ (Q) + 8P(2ymE1)~~~ (7)m= ~Rmfl(Q)YILEQ. Thus, for ordinary supergravity, the constraint R~~m (F) = 0 is enough.due But to for8~,w,~’ conformal supergravity one has one extra independent field to consider, namely A~.Now with= 1EQY5&[ÔQ( j), 60( 2)]A~ 8(lEyme)A — (ii2y5 ( ~)&— 1 ~-~2) (8)and indeed ~ is such that the last term turns into a term with R,~~(A) such that the sum is again ageneral coordinate transformation.Thus the constraints on curvatures have the geometrical significance of turning P-gauge transformations,defined by the group in the tangent space, into general coordinate transformations in the basemanifold.The gauge algebra is thus given by[o(e~), 5( ~)]h~= o(fA ~~eC)+fA~6~(eA)hBeC_ 1~-~2. (9)Since only ö’~is nonzero, only the (0, 0), (0, K), (0, S), (0, D), (0, M) or (Q, A) relations might bemodified. However, K, S, D, M, A rotate physical fields into physical fields so that only the (0, Q)anticommutator is modified. One finds uniformly on e~,~, A,. and b~,and hence (because of theJacobi identities) also on any function of these fields (in particular on q5~,f~,w~”~)F~( \ ~ I \] (~A\j ~ I_LA mn\j ~t”~~~ii,‘-‘Ok~2)J — ‘~gen.coord~S I ULorentz~ S W~ j (‘chira!~ 5+ ôo(—~frA)+6~(—~~) (10)11Awith ~ = ~E2yk 1. If one puts b,., equal to zero, as well as ob,~,the gauge algebra still closes but now anextra S-supersymmetry transformation is present,extra 1 —ô~ (~(~e~)ë1y~ — 1 ~-~2). (11)

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!