La Sapienza honours Bernardini's 75 years

Carlo Bernardini, one of the physicists who built the first electron-positron storage ring, AdA in 1960, celebrated his 75th birthday at a symposium held in his honour at the University of Rome La Sapienza. A description of the making of AdA and its first operation was reported in Il Nuovo Cimento on 19 December 1960 in an article entitled "The Frascati Storage Ring", by Bernardini, Gianfranco Corazza, Giorgio Ghigo and Bruno Touschek. Forty-five years later, Bernardini retired from teaching and his friends and colleagues paid homage to his long and multifaceted career.

The symposium, held on 5 December 2005, contained both a physics and technology session, including talks by Nicola Cabibbo, Emilio Picasso and Ugo Amaldi, as well as a science and society session. Cabibbo described the long list of physics results to have come out of electron-positron storage rings, from the early days of the first paper by Cabibbo and Raul Gatto on physics at electron-positron accelerators, published in Physical Review Letters in March 1960, to the latest Belle and BaBar results, mentioning also the Large Electron-Positron collider (LEP) achievements in precision physics. Picasso recalled the early days of LEP construction, including the search for the site and the final decision. Amaldi focused on the importance of accelerators in medicine, noting the existence of nearly 9000 such accelerators in the world. Another testimonial was given by Giuseppe Di Giugno, who recalled the historic night when electrons were first accumulated in AdA.

The afternoon session on science and society was chaired by Tullio de Mauro, former Minister of Education and well known linguistic scholar, who illustrated Bernardini's activity as Senator of the Italian parliament and his tenure as dean of science at La Sapienza University. The session also emphasized Bernardini's participation in the peace movement, Unione Scienziati Italiani per il Disarmo, and his contribution to public awareness of science as director of the science magazine, Sapere. Luciano Maiani, former director-general of CERN, chaired the final session, in which further testimonials were given by Bernardini's students and colleagues, among them Michelangelo de Maria, who noticed the extraordinary capacity of Bernardini to communicate with friends and antagonists alike. The symposium was closed by Giorgio Salvini, former president of the Instituto Nazionale di Fisica Nucleare and director of Frascati when AdA was built.

Princeton celebrates Polyakov's 60th

A special symposium was held at Princeton University on 5-6 November 2005 to honour Alexander Polyakov, a leading figure in theoretical high-energy physics. Polyakov received his Masters degree from Moscow Institute of Physics and Technology and his PhD from the Landau Institute of Theoretical Physics in Chernogolovka, where he stayed until 1989, before moving to Princeton University in 1990.

The first of Polyakov's papers, "Spontaneous symmetry breaking of strong interaction and absence of massless particles", was written with Alexander Migdal in early 1964, before Peter Higgs' famous papers were published. The two theorists, both 19 at the time, had essentially discovered what later became known as the Higgs mechanism. Owing to several unfortunate circumstances, this Migdal-Polyakov paper was published in the Journal of Experimental and Theoretical Physics only in 1966, two years after it had been completed.

Polyakov has since been instrumental in numerous developments with a profound impact on high-energy physics: the Migdal-Polyakov conformal bootstrap, 't Hooft-Polyakov monopoles, Belavin-Polyakov-Schwarz-Tyupkin instantons, Polyakov's Liouville theory and Polyakov strings. His 1984 paper "Infinite conformal symmetry in two-dimensional quantum field theory", with Alexander Belavin and Alexander Zamolodchikov, has classic status; it became a Bible for string theorists. He was awarded the Dirac Medal in 1986, and the Lorentz Medal in 1994 for his work in quantum field theory, especially the theory of critical phenomena.

In the past decade Polyakov's results (along with those of Juan Maldacena and Edward Witten) played a crucial role in the emergence of the so-called holographic descriptions of quantum chromodynamics. Within this approach the theory of quarks and gluons is presented as a limiting 4D theory at the boundary of the 5D bulk, which is governed by a certain gravity model (AdS/CFT correspondence and its modifications). This line of research is currently experiencing an explosive development.

Polyakov's other interests include theory of turbulence and string cosmology. He has been a key contributor to Burgers turbulence, which is now a central interest for much of the hydrodynamics community.