• 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.


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


(propose a free ad)

Site Statistics

205 submissions , 163 unreviewed
5,047 questions , 2,200 unanswered
5,345 answers , 22,709 comments
1,470 users with positive rep
816 active unimported users
More ...

  Manifest covariant color superconductivity?

+ 1 like - 0 dislike

@JiaYiyang wrote:

I think color-superconductivity would count. Although the formalism treating it is often not manifestly covariant (which is not surprising since e.g. it's often dealt with in thermal QFT context),  it's still a QCD phenomenon after all.

How can it be manifest? Doesn't the permanent presence of matter always break Lorentz covariance?

asked Jan 6, 2016 in Theoretical Physics by Arnold Neumaier (15,787 points) [ no revision ]

I have not seen a completely manifest covariant treatment. The question is why bother?

@JiaYiyang Well, since you only wrote ''often'' I concluded that you seem to have treatments in mind where covariance is manifest.  

Why bother? Since in the context of your remark that I cited covariance is essential (though not necessarily manifest covariance). But it seems to me that there is no covariance since matter always defines a preferred frame. 

 Well, since you only wrote ''often'' I concluded that you seem to have treatments in mind where covariance is manifest.  

Sorry for the confusion, I wrote "often" simply to be safe, just in case there is actually a covariant treatment out there I haven't seen. 

The difference between color-superconductivity and ordinary electron-superconductivity is that the dynamics is treated relativistically (because it's often high-density that is discussed), so in expressions such as $\langle q q\rangle$, the $q$ is still relativistically quantized. But the thermal state certainly breaks manifest covariance. (Aside: maybe I should also say, another difference is that in color-superductivity there's an obvious channel for pairing, i.e. color-Coulomb interaction, which is a plain QCD effect; while in normal electron superconductivity, the pairing mechanism is much subtler, i.e. phonon exchange. In this sense, color-superconductivity theory is much closer to QCD than electron-superconductivity to QED.)

In any case, we know physically when evaluating (thermal-sense) color-condensate such as $\langle qq \rangle$ there is a contribution from the true vacuum, so the true vacuum vev has to be defined.

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:
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