Samuel Jarman, SciencePOD

Lattice Gauge Theory (LGT) provides a mathematical framework for studying the properties of quarks, and the strong force which binds them together. John Kogut is a pioneer of LGT, and provided his perspectives on the foundations of the theory through a short talk at the Lattice 2024 Conference, now published in EPJ H.

50 years on from its origins in the 1970s and 80s, Kogut brings the early years of LGT to life through a series of personal anecdotes and recollections of how the theory came to enter the mainstream of high energy theoretical physics.

Kogut begins his recollection with his arrival at Stanford University in 1967, where he developed a close working relationship with JD Bjorken. Together with Richard Feynman, Bjorken had previously made important advances in experimental techniques for probing the inner structures of protons, neutrons, and other hadrons.

These first few years were incredibly dynamic: with Kogut and his colleagues refining models of hadrons; explaining how their constituent quarks behave during high-energy particle collisions; and simplifying descriptions of the motions of energetic particles. Kogut’s own work culminated in a fiery defence of his final thesis against Lenny Susskind – who would soon become his close friend.

During his postdoc at the Institute for Advanced Studies at Princeton, Kogut worked with Ken Wilson to bridge the gap between condensed matter and high-energy physics. Soon afterwards, he joined Lenny Susskind at Tel Aviv University. There, the pair would study and popularise a simplified framework for exploring the nature of quarks and their interactions, which illustrated the phenomenon of ‘quark confinement’. Named the ‘Schwinger model’, after its invention by Julian Schwinger in 1962, it had an immense impact on the field.

In the following years, Kogut continued his collaboration with Wilson and Susskind. Building on their previous ideas, the physicists laid the foundations for LGT to show how the theory is connected to the strong interaction – cementing its relevance in mainstream theoretical physics. In particular, their ‘Hamiltonian formulation’ of LGT has opened up the frontiers of gauge theories to many disciplines: from condensed matter to quantum information science.

Looking to the future, Kogut is now hopeful that the groundbreaking early work of him and his colleagues will inspire progress in numerous cutting-edge fields of physics and technology: from advances in quantum computing, to deeper insights into the elusive nature of quantum entanglement and quantum gravity.

Reference

J B Kogut, Lattice Gauge Theory Before Lattice Gauge Theory, Eur. Phys. J. H, 49, 25 (2024). https://doi.org/10.1140/epjh/s13129-024-00089-0