Phases Of Adjoint QCD_3 And Dualities

[David Neves]

Here is an interesting paper where they uncover new dualities by studying adjoint QCD in 2 + 1 dimensions.

https://arxiv.org/pdf/1710.03258.pdfPhases Of Adjoint QCD_3 And Dualities

by Jaume Gomis, Zohar Komargodski, and Nathan Seiberg

We study 2+1 dimensional gauge theories with a Chern-Simons term and a fermion in the adjoint representation. We apply general considerations of symmetries, anomalies, and renormalization group flows to determine the possible phases of the theory as a function of the gauge group, the Chern-Simons level
k, and the fermion mass. We propose an inherently quantum mechanical phase of adjoint QCD with small enough k, where the infrared is described by a certain Topological Quantum Field Theory (TQFT). For a special choice of the mass, the theory has N = 1 supersymmetry. There this TQFT is accompanied by a
massless Majorana fermion – a Goldstino signaling spontaneous supersymmetry breaking. Our analysis leads us to conjecture a number of new infrared fermion-fermion dualities involving SU, SO, and Sp
gauge theories. It also leads us to suggest a phase diagram of SO/Sp gauge theories with a fermion in the traceless symmetric/antisymmetric tensor representation of the gauge group. As a by-product of our analysis, we conjecture the value of the time-reversal anomaly ν of U (n)_n,2n, SO(n)_n, and Sp(n)_n Chern-Simons theories.

 

[AndyW]

Thank you for sharing this interesting paper on the study of adjoint QCD in 2+1 dimensions. I find this research to be particularly intriguing as it uncovers new dualities and provides insights into the possible phases of the theory.

The authors' approach of using symmetries, anomalies, and renormalization group flows to determine the phases of the theory is a rigorous and comprehensive method. Their proposal of an inherently quantum mechanical phase of adjoint QCD with small Chern-Simons level, where the infrared is described by a Topological Quantum Field Theory, is a significant contribution to the field.

Furthermore, the discovery of a special mass choice that leads to N=1 supersymmetry and the presence of a massless Majorana fermion, indicating spontaneous supersymmetry breaking, is a major advancement in our understanding of this theory.

The authors' conjectures on new infrared fermion-fermion dualities involving SU, SO, and Sp gauge theories, as well as their suggested phase diagram for SO/Sp gauge theories with a fermion in the traceless symmetric/antisymmetric tensor representation, provide valuable insights for future research.

Lastly, the authors' conjecture on the value of the time-reversal anomaly for U(n)_n,2n, SO(n)_n, and Sp(n)_n Chern-Simons theories is a significant contribution that can guide future experimental studies.

Overall, this paper presents valuable findings that contribute to our understanding of adjoint QCD in 2+1 dimensions and opens up new directions for further research. Thank you for sharing this fascinating work with the scientific community.