2023 Dirac Awards Announced

On August 8, the International Centre for Theoretical Physics (ICTP) awarded the 2023 Dirac Medal to four physicists for their extensive contributions to string theory, a mathematical framework for fundamental physics that seeks to describe the entire universe.

The four recipients are:

- Jeffrey Harvey. the Enrico Fermi Distinguished Service Professor of Physics at the University of Chicago. He is an elected fellow of the American Academy of Arts and Sciences and the American Physical Society, and a member of the National Academy of Sciences. He is a member of the Scientific Council of the International Center for Theoretical Physics and was a trustee of the Institute for Advanced Study in Princeton, New Jersey. He received his Ph.D. from the California Institute of Technology in 1981 and was a postdoctoral researcher and teacher at Princeton University before moving to the University of Chicago in 1989.

- Igor Klebanov. is the Eugene Higgins Professor of Physics at Princeton University and Director of the Princeton Center for Theoretical Science. He is also Director of the Simons Foundation and the Quantum Chromodynamics String Collaboration. He received his PhD in theoretical high-energy physics from Princeton University, followed by postdoctoral research at the Stanford Linear Accelerator Center. He is a member of the American Academy of Arts and Sciences and a member of the National Academy of Sciences. His honors include the 2014 Tomassoni Prize of the Sapienza University of Rome.

- Stephen Shenker. is the Richard Herschel Weiland Professor of Physics at Stanford University. He received his Ph.D. from Cornell University and was a postdoctoral fellow at the University of Chicago and the Santa Barbara Institute for Theoretical Physics.Shenker is a member of the American Academy of Arts and Sciences and a member of the U.S. National Academy of Sciences.He served as the director of Stanford's Institute for Theoretical Physics from 1998 to 2008.In 2010, he was awarded the Lars Onsager Prize from the American Physical Society.

- Leonard Susskind is the Felix Bloch Professor of Theoretical Physics at Stanford University. He is a member of the U.S. National Academy of Sciences and the American Academy of Arts and Sciences, an associate professor at the Perimeter Institute for Theoretical Physics in Canada, and a distinguished professor at the Korea Advanced Institute.Susskind received his Ph.D. from Cornell University.In 1997 he was awarded the J.D. degree in physics and physics for "seminal contributions to hadronic string models, lattice gauge theory, quantum chromodynamics, and dynamical symmetry breaking " and received the J.J. Sakurai Prize.Susskind is widely regarded as one of the founding fathers of string theory.

From left to right: Jeffrey Harvey, Igor Klebanov, Stephen Shenker, Leonard Susskind.

The award recognizes "their seminal contributions to perturbative and non-perturbative string theory and quantum gravity, especially as related to anomalies, duality, black holes and holography".

Atish Dabholkar, Director of ICTP, said, "This year's laureates have made many original contributions to the development of a theoretical framework for string theory with the goal of unifying all physical interactions, including gravity. Their work has led to new insights into black hole physics and a major conceptual breakthrough by realizing new principles of duality and holography."

Physicists consider string theory to be the unifying theory of physics, combining Einstein's general theory of relativity (which describes gravity) and quantum mechanics (which describes the fundamental elements of matter). It does this by re-imagining the basic building blocks of matter as tiny vibrating strings. Just as different vibrational modes of a violin string produce different notes, different vibrational states of a string produce different elementary particles, such as electrons or neutrinos, and determine their properties, such as mass or charge.

String theory is important for solving several problems in fundamental physics and has been applied to a variety of fields such as black holes, the early universe and condensed matter research. Thanks to its complex and rigorous formulation, string theory has driven significant developments in pure mathematics.

Theoretical physicist Juan Maldacena is a member of the Dirac Medal selection committee. "We use the former to describe matter, light, atoms and subatomic particles, and the latter to describe spacetime, the expanding universe and gravity. String theory is a theory under construction whose goal is to provide a quantum description of spacetime; it provides a mathematical framework that is an important step toward achieving this goal."

Maldacena emphasized that string theory provides important insights into the quantum aspects of black holes. "For example, in string theory, black holes seen from the outside are subject to the usual rules of quantum mechanics. in the 1970s, black holes were observed to obey a number of relations similar to those of thermodynamics. String theory demonstrates that these relations can be interpreted statistically in the standard way in a complete quantum theory. These include the explanation of entropy in terms of state numbers, and the statistical origin of Hawking radiation."

This year's Dirac Medal winners have made a wide range of contributions to string theory, reflecting the breadth of the string theory framework. Below is a summary of the winners' string theory-related work:

Jeffrey Harvey (with Gross, Martinec, and Rohm) discovered heterotic string theory, which naturally leads to grand unified theories that can be incorporated into the Standard Model of particle physics. His work (with Dixon, Vafa, and Witten) on orbitals provided a precise worldsheet construction for such models. He was a pioneer in the study of solitons and branes and played a crucial role in the discovery and understanding of pairwise symmetry. His work (with Callan) on anomalous inflaton has important applications in condensed matter physics.

Igor Klebanov (with Gubser and Polyakov) compiled a precise introduction to the holographic AdS/CFT correspondence in a seminal paper on the subject. He (with Strassler) constructed examples of holographic gravitational pairings for constrained gauge theories, which have many applications in model building.

Stephen Shenker and Leonard Susskind (with Banks and Fischler) first introduced a nonperturbative formulation of M-theory and string theory by providing a restriction procedure for describing S-matrices.Other influential contributions by Shenker include phase structure analysis of lattice gauge theories, classification of unitary two-dimensional conformal field theories, covariant formulations of superstring theory, and low-dimensional covariant formulations of low-dimensional string theory. the covariant formulation of superstring theory, the nonperturbative formulation of low-dimensional string theory, and a new connection between chaos and black holes.

Susskind was one of the first to recognize that dyadic models could be interpreted in terms of strings. His other influential contributions include his work on Hamiltonian lattice canonical field theory, holography, and the connection between complexity theory and black holes.

About the Dirac Medal

The ICTP Dirac Medal is awarded in honor of Paul Dirac, one of the greatest physicists of the 20th century and a devoted friend of the Center. The Medal is awarded annually on August 8, the date of Dirac's birth, to scientists who have made significant contributions to theoretical physics.

The ICTP Dirac Medal was first awarded in 1985. The laureates consist of the world's top physicists, many of whom have gone on to win Nobel Prizes and Fields Medals. An international committee of distinguished scientists selects the laureates from a list of nominated candidates. The award ceremony will be held in 2024, and the 2023 laureates will deliver speeches at the ceremony.

Reference link:

https://www.ictp.it/news/2023/8/ictp-announces-2023-dirac-medallists