I had the marvelous good fortune to be Ken Wilsons graduate student at the Physics Department, Cornell University, from 1972 to 1976. In this article, I present some recollections of how this came about, my interactions with Ken, and Cornell during t
his period; and acknowledge my debt to Ken, and to John Wilkins and Michael Fisher, who I was privileged to have as my main mentors at Cornell. I end with some thoughts on the challenges of reforming education, a subject that was one of Kens major preoccupations in the second half of his professional life.
We study the finite-size spectrum of the O($N$) symmetric Wilson-Fisher conformal field theory (CFT) on the $d=2$ spatial-dimension torus using the expansion in $epsilon=3-d$. This is done by deriving a set of universal effective Hamiltonians describ
ing fluctuations of the zero momentum modes. The effective Hamiltonians take the form of $N$-dimensional quantum anharmonic oscillators, which are shown to be strongly coupled at the critical point for small $epsilon$. The low-energy spectrum is solved numerically for $N = 1,2,3,4$. Using exact diagonalization (ED), we also numerically study explicit lattice models known to be in the O($2$) and O($3$) universality class, obtaining estimates of the low-lying critical spectrum. The analytic and numerical results show excellent agreement and the critical low energy torus spectra are qualitatively different among the studied CFTs, identifying them as a useful fingerprint for detecting the universality class of a quantum critical point.
John Adams acquired an unrivalled reputation for his leading part in designing and constructing the Proton Synchrotron (PS) in CERNs early days. In 1968, and after several years heading a fusion laboratory in the UK, he came back to Geneva to pilot t
he Super Proton Synchrotron (SPS) project to approval and then to direct its construction. By the time of his early death in 1984 he had built the two flagship proton accelerators at CERN and, during the second of his terms as Director-General, he laid the groundwork for the proton-antiproton collider which led to the discovery of the intermediate vector boson. How did someone without any formal academic qualification achieve this? What was the magic behind his leadership? The speaker, who worked many years alongside him, will discuss these questions and speculate on how Sir John Adams might have viewed todays CERN.