Bell's Universe: A Personal Recollection

TL;DR

This paper is a personal recollection of John Bell's contributions to physics, highlighting his work on quantum theory, entanglement, and Bell inequalities, and their influence on the author's research.

Contribution

It provides a personal perspective on Bell's groundbreaking work in quantum physics, including contextuality, nonlocality, and entanglement, with insights into his collaborations and influence.

Findings

Bell's work on quantum contextuality and nonlocality

Experimental verification of Bell inequalities

Geometric aspects of quantum states

Abstract

My collaboration and friendship with John Bell is recollected. I will explain his outstanding contributions in particle physics, in accelerator physics, and his joint work with Mary Bell. Mary's work in accelerator physics is also summarized. I recall our quantum debates, mention some personal reminiscences, and give my personal view on Bell's fundamental work on quantum theory, in particular, on the concept of contextuality and nonlocality of quantum physics. Finally, I describe the huge influence Bell had on my own work, in particular on entanglement and Bell inequalities in particle physics and their experimental verification, and on mathematical physics, where some geometric aspects of the quantum states are illustrated.