Title: A complexity-theoretic solution to Connes' Embedding Problem
Speaker: Zhengfeng Ji（University of Technology Sydney）
Time: 15:00-16:00, July6
Location: Tecent Meeting, Tecent Meeting ID: 741 785 636
Abstract: This talk aims to introduce how ideas and techniques from quantum information theory and complexity theory help to resolve Tsirelson's problem in physics and Connes' embedding problem in mathematics. In this complexity-theoretic approach, the central problem is to understand the complexity of approximating the entangled value of nonlocal games, a model used to study constraint satisfaction problems and interactive proofs in computer science and Bell inequalities in quantum mechanics. The problem is shown to be as hard as the Halting problem and this implies a negative answer to Tsirelson's problem via known connections. At the core of the proof is a recursive gap-preserving compression lemma, which in turn leverages many recent ideas from the study of nonlocal games.
Meeting Link: https://meeting.tencent.com/s/CMVthX9Fkg65
Video Link: https://www.bilibili.com/video/BV1cT4y1E7vn
Slides: 
Complexity-Connes.pdf
