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

  Framed Wilson Operators, Fermionic Strings, and Gravitational Anomaly in 4d

Originality
+ 2 - 0
Accuracy
+ 0 - 0
Score
0.00
1318 views
Referee this paper: arXiv:1404.4385

Please use comments to point to previous work in this direction, and reviews to referee the accuracy of the paper. Feel free to edit this submission to summarise the paper (just click on edit, your summary will then appear under the horizontal line)

(Is this your paper?)


Summary credit to author Ryan Thorngren

Thought I'd give this a try, especially since Xiao-Gang did as well. :)

I was originally interested in the question of describing boundary topological order for bosonic phases protected by time reversal, though I believe the applications of this sort of investigation are far-reaching in physics. Even though these systems are bosonic, it is known that ``fermionic" things happen in the topological order, eg. Kramers degeneracy and fermionic spin-statistics. This is because the unoriented cobordism invariants, the Stiefel-Whitney classes, are the obstruction classes for things like spin structures. As we go to higher dimensions, what does the topological order--eg. in 3+1d--look like? It turns out to have some sort of fermionic string.

The approach is to think of the unoriented bordism class of spacetime as the configuration of a gauge field. Since this is specified by the Stiefel-Whitney classes, we can consider this as a collection of discrete Z/2 gauge fields in each form degree. Then I define physically the electric and magnetic operators corresponding to such a thing and discuss how they can end.

Some elementary algebraic topology is used to figure out pictorially what it means for a string to be fermionic.

At the end of the paper I show that QED with fermionic electron and fermionic magnetic monopole has a global gravitational anomaly.

summarized by dimension10
paper authored Apr 15, 2014 to hep-th by Ryan Thorngren
  • [ revision history ]
    edited Nov 15, 2014 by dimension10

    Your Review:

    Please use reviews only to (at least partly) review submissions. 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 review 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$\hbar$ysicsOverflo$\varnothing$
    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
    ...