E-lab Seminar
Upcoming
| Date | Tue Nov 17 2026 (17:00 - 18:00) |
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| Speaker |
Ryo Yokokura (Keio University) |
| Title | Non-Abelian A_4 vortices in SO(3) gauge theory and non-invertible symmetries |
| Abstract | We construct finite-tension non-Abelian vortex solutions in a renormalizable (3+1)-dimensional SO(3) gauge theory Higgsed to the tetrahedral group A_4 by a Higgs field in the spin-3 representation. Since the vacuum manifold is SO(3)/A_4, the vortices are characterized by the non-Abelian fundamental group \pi_1(SO(3)/A_4)\simeq \tilde{A}_4, the binary tetrahedral group. We obtain explicit axisymmetric vortex solutions carrying holonomies corresponding to the order-two and order-three conjugacy classes of A_4, determine their tensions numerically, and show that they exhibit type-I, type-II, and Bogomol'nyi--Prasad--Sommerfield-like behavior depending on the Higgs and gauge boson mass ratios. The vortices are classified by conjugacy classes of \tilde{A}_4, while their infrared descriptions are labeled by conjugacy classes of A_4. We further demonstrate that the smooth finite-tension vortices reduce in the infrared to Gukov--Witten surface operators of the A_4 discrete gauge theory, thereby establishing a finite-energy ultraviolet completion of non-invertible defects in a renormalizable gauge-Higgs theory. |
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| Slide/Video |
| Date | Tue Dec 01 2026 (17:00 - 18:00) |
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| Speaker |
Daisuke Jido (Tokyo Inst. Tech.) |
| Title | TBA |
| Abstract | TBA |
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| Slide/Video |
| Date | Tue Dec 08 2026 (17:00 - 18:00) |
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| Speaker |
Yu Nakayama (YITP, Kyoto University) |
| Title | TBA |
| Abstract | TBA |
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| Slide/Video |
| Date | Wed Dec 16 2026 (13:00 - 14:00) |
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| Speaker |
Ryosuke Sato (Osaka University) |
| Title | A particle on a ring or: how I learned to stop worrying and love theta-vacua |
| Abstract | Although the QCD Lagrangian allows CP violation by the theta-term, no such effect has been observed yet. This puzzle is called the strong CP problem. In this talk, I will review a recent debate on the order of limit in the path integral formulation of strong CP violation, and discuss the validity of the formulation by focusing on quantum mechanics on a circle. |
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| Slide/Video |
| Date | Tue Jan 19 2027 (17:00 - 18:00) |
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| Speaker |
David Vegh (QMUL) |
| Title | TBA |
| Abstract | TBA |
| Remarks | Online talk |
| Slide/Video |
| Date | Wed Feb 24 2027 (13:00 - 14:00) |
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| Speaker |
Kazunori Nakayama (Tohoku University) |
| Title | TBA |
| Abstract | TBA |
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