Degenerate Ground States

Abstract: Despite their common occurrence in our studies, degenerate spectra are rare and special. In this talk, we will briefly sketch the argument of eigenvalue repulsion and explain why degenerate Hamiltonians are not the norm. We will also demonstrate how familiar mechanisms for degeneracy fail in Quantum Mechanics. Next, anomalies will be discussed as an invariant for diagnosing degeneracy. To conclude, we will discuss projective representations and how to realise anyon parastatics on the torus and the associated ground state degeneracy, to set the scene for future discussions on fusion, anomalies, and inflow.

condensed mattergeneral relativity and quantum cosmologyHEP - theorymathematical physicsdifferential geometry

Audience: advanced learners

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Europe and Pacific Theoretical Physics

Series comments: European and Pacific Theoretical Physics is a group that runs online seminars and talks across broad topics in mathematical and theoretical physics. Our goal is to share concepts across continents to bring about a deeper understanding of cutting-edge topics in physics.

Our current focus is on Generalised (Categorical) Symmetries. We will follow the lectures notes found here: arxiv.org/pdf/2411.09082 . The talks are informal, and anyone can participate, so please reach out if you would like to present one week!

The reading course seminars are scheduled to resume January. If you would like to present material, please reach out. Extended notes & presentation material are uploaded to "Past talks". Please click on the title of a talk, and then click on "paper" or "slides" to see more.

Zoom link: unibe-ch.zoom.us/j/6801537904

Talks may be uploaded to YouTube: www.youtube.com/@eupactp

Mailing list sign-up: forms.gle/StswcjC7RbXWuvAr8

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