Talk:N = 4 supersymmetric Yang–Mills theory

From Wikipedia, the free encyclopedia
Jump to: navigation, search

In the article the Lagrangian is given as: 
L = tr \left\{\frac{1}{2g^2}F_{\mu\nu}F^{\mu\nu}+\frac{\theta_I}{8\pi^2}F_{\mu\nu}\bar{F}^{\mu\nu}- i \gamma^a\sigma^\mu D_\mu \lambda_a -D_\mu X^i D^\mu X^i
+g C^{ab}_i \lambda_a[X^i,\lambda_b] +C_{iab}\lambda^a[X^i,\lambda^b]+\frac{g^2}{2}[X^i,X^j]^2
\right\}

But in the reference the Lagrangian reads: 
L = tr \left\{ - \frac{1}{2g^2} F_{\mu\nu} F^{\mu\nu} + \frac{\theta_I}{8\pi^2} F_{\mu\nu}\tilde F^{\mu\nu} - i \bar \lambda^a \bar \sigma^{\mu}D_{\mu}\lambda_a
- D_{\mu}X^i D^{\mu} X^i + g C^{ab}_i \lambda _a [X^i, \lambda_b]
+\bar C_{iab} \bar \lambda^a [X^i, \bar \lambda^b] + \frac{g^2}{2} [X^i, X^j]^2 \right\}

I am not an expert on this topic, maybe the two formulations are equivalent or the source is wrong.

Randrian (talk) 08:02, 14 September 2012 (UTC)

Good spot. The minus sign was missing. Proving the importance of references! — Preceding unsigned comment added by 86.156.93.90 (talk) 19:28, 16 September 2012 (UTC)

Basic Question[edit]

The title of this article is N = 4 supersymmetric Yang–Mills theory. What is confusing to me, is whether there is a difference between a "supersymmetric" theory and a basic N=4 Yang-Mills theory. If all N=4 Yang-Mills models support SUSY interpretation, then can we rename the article as N = 4 Yang–Mills theory, and explain in the article that it must contain SUSY? We could create redirects from the current title, even. If there is a difference, I feel the article shous spend more time explaining the SUSY aspect of the distinction. 70.247.175.236 (talk) 18:19, 2 January 2014 (UTC)

It is a sort of redundant name, but that is what it is called. Plus it emphasizes how super this theory is (good or bad thing depending on your goal). AHusain (talk) 05:44, 4 January 2014 (UTC)