李志金 博士学术报告
Title: Cracking the critical flavor number of QED3 with conformal bootstrap
Speaker: Dr. Zhijin Li（李志金）
Affiliation: Yale University, U.S.
Time:16:00-17:00, Tuesday, 27th September, 2022 (UTC+8, Beijing Time)
Venue: Zoom Meeting
Abstract
Three dimensional quantum electrodynamics (QED3) coupled to fermions is expected to have a critical flavor number of fermions, which separates the conformal phase from the chiral symmetry breaking phase in the infrared limit. The critical flavor number has been extensively studied in the past decades without a conclusive answer. In this talk, I will show that the conformal bootstrap can shed new light for this long-standing problem.
I will firstly show that the widely interested SO(5)/O(4) symmetric deconfined quantum critical points are just below a new family of kinks in the SO(N) vector bootstrap bounds, while the lattice and perturbative estimates of the critical indices can be excluded by the bootstrap bounds associated with few reasonable assumptions on the spectrum. Then I will explain a remarkable algebraic structure in the bootstrap crossing equations and its fundamental role in bootstrap studies. I will show that the bootstrap bounds are nearly saturated by conformal QED3 after introducing assumptions relevant to conformal QED3. In particular the CFT data of four flavor QED3 can be isolated into a closed region and the bootstrap bounds are beautifully consistent with some large Nf perturbative results. The bootstrap results suggest the critical flavor number of QED3 is slightly above 2 while below 4. I will discuss some predictions and new problems that arose in bootstrap studies.
About the Speaker
Dr. Zhijin Li:
PhD: 2011-2017: Texas A&M University, advisor: Dimitry Nanopolous and Christopher Pope
Postdoc: 2018-2019: Porto University, fellowship in Simons collaboration of conformal bootstrap;
2019-2022: Yale University, postdoctor at Yale University.
Dr. Zhijin Li joins the Shing-Tung Yau Center of Southeast University as associate professor in September 2022.
The seminar will be broadcasted online by Zoom.
Interested people are free to join, without registration in advance.
URL：https://us02web.zoom.us/j/3854420225?pwd=SXY4eWJKOTBFZWJDaE16aXpTamY1QT09
Meeting ID: 385 442 0225
Passcode: yauc