Quantcast
  • Register
PhysicsOverflow is a next-generation academic platform for physicists and astronomers, including a community peer review system and a postgraduate-level discussion forum analogous to MathOverflow.

Welcome to PhysicsOverflow! PhysicsOverflow is an open platform for community peer review and graduate-level Physics discussion.

Please help promote PhysicsOverflow ads elsewhere if you like it.

News

PO is now at the Physics Department of Bielefeld University!

New printer friendly PO pages!

Migration to Bielefeld University was successful!

Please vote for this year's PhysicsOverflow ads!

Please do help out in categorising submissions. Submit a paper to PhysicsOverflow!

... see more

Tools for paper authors

Submit paper
Claim Paper Authorship

Tools for SE users

Search User
Reclaim SE Account
Request Account Merger
Nativise imported posts
Claim post (deleted users)
Import SE post

Users whose questions have been imported from Physics Stack Exchange, Theoretical Physics Stack Exchange, or any other Stack Exchange site are kindly requested to reclaim their account and not to register as a new user.

Public \(\beta\) tools

Report a bug with a feature
Request a new functionality
404 page design
Send feedback

Attributions

(propose a free ad)

Site Statistics

205 submissions , 163 unreviewed
5,082 questions , 2,232 unanswered
5,353 answers , 22,789 comments
1,470 users with positive rep
820 active unimported users
More ...

  Difference between the Rarita-Scwinger field and the gravitino?

+ 2 like - 0 dislike
682 views
The Rarita-Scwhinger field is a spin 3/2 field $\psi_{\mu}^{\alpha} $ but this looks a lot like the gravitons found in string theories, for example it looks like the gravitinos in Ibanez's and Uranga's book of string theory. Therefore why we need two names for the same thing (if the same)? Is its supersymmetry global or local?
asked Jan 4, 2015 in Theoretical Physics by Outlander (95 points) [ no revision ]
recategorized Jan 6, 2015 by dimension10

1 Answer

+ 4 like - 0 dislike

The graviton we find in string theory and in supergravity in a specific limit is the Rarita-Schwinger field. Specifically in order to get supergravity (let us forget string theory for now) we need to gauge the supersymmetry transformation parameters, i.e. $\epsilon_{\alpha} \to \epsilon_{\alpha}(x)$. Then the associated gauge field is the vector-spinor $\psi_{\alpha \, \mu}$ where $\alpha$ is the internal symmetry index and $\mu$ is the Lorentz index. Now gauging this parameter, which is a constant spinor, we get supergravity which is an interacting theory. The Rarita-Schwinger field is nothing more than the non-interacting or free limit. At this limit the various fields of the theory (which depend a lot on the supersymmetry(ies)) do not interact and we can consider them case by case. Then the vector-spinor field $\psi_{\alpha \, \mu}$ is the Rarita-Schwinger field which transforms in the $$ \Big( (1/2, 0) \oplus (0,1/2)\otimes (1/2,1/2) \Big) $$ of the Lorentz group. Just note that general supergravity theories restrict a lot the type of spinor $\psi_{\alpha \, \mu}$ is normally but for a free theory and for any dimension $d$ one can use a complex spinor with $2^{d/2}$ components. A nice review I found was this one where you will find much more (and accurate) info. 

answered Jan 4, 2015 by conformal_gk (3,625 points) [ no revision ]

Your answer

Please use answers only to (at least partly) answer questions. To comment, discuss, or ask for clarification, leave a comment instead.
To mask links under text, please type your text, highlight it, and click the "link" button. You can then enter your link URL.
Please consult the FAQ for as to how to format your post.
This is the answer box; if you want to write a comment instead, please use the 'add comment' button.
Live preview (may slow down editor)   Preview
Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
If you are a human please identify the position of the character covered by the symbol $\varnothing$ in the following word:
p$\hbar$ysicsO$\varnothing$erflow
Then drag the red bullet below over the corresponding character of our banner. When you drop it there, the bullet changes to green (on slow internet connections after a few seconds).
Please complete the anti-spam verification




user contributions licensed under cc by-sa 3.0 with attribution required

Your rights
...