Published online by Cambridge University Press: 01 June 2011
From table 5.1 it can be seen that in the case of extended supersymmetry of type N, a supermultiplet must contain states of helicity h such that |h| ≥N/4. This means that for N > 2 we have no supermultiplets with scalars and spin one-half fermions only; for N > 4 we must exceed helicity one, (thus no Yang–Mills supermultiplets for N > 4) and as of N ≥ 9 states of helicity larger than two make an appearance (the critical values N = 2, 4, 8 correspond to the CPT self-conjugate cases mentioned in chapter 5). There are strong reasons to believe (though really no proof as yet) that nontrivial interacting theories containing fields of spin five-halves and higher in the lagrangian are inconsistent (Aragone & Deser 1979, Curtright 1979 Berends, van Holten, de Wit & van Nieuwenhuizen 1980). Hence one is limited to supergravities with N ≤ 8.
The ‘natural’ N = 1 supergravity in four space–time dimensions has just been presented. Here we ask for the extended supergravities (N > 1). The corresponding lagrangians can be constructed. We shall not do so here, but will content ourselves with a few remarks on these lagrangians and on the phenomenology of the N = 8 theory. First of all, the elegant construction (MacDowell & Mansouri 1977) we presented for the N = 1 case, already fails at the N = 2 level, as in addition to the types of terms in the ansatz (22.5) it requires terms explicitly containing the vierbein or metric (Townsend & van Nieuwenhuizen 1977).
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.