ictp-newsletter-145-v6-digital-1gravitational waves arriving at Earth from the distant universe on 14 September 2015. For his contributions to LIGO and to gravitational wave research,

News from ICTP Spring–Summer 2018 145

The Abdus Salam International Centre for Theoretical Physics (ICTP) is governed by the United Nations Educational, Scientific and Cultural Organization (UNESCO), the International Atomic Energy Agency (IAEA), and Italy. It is a UNESCO category 1 institute.

News from ICTP is a bi-annual publication designed to keep scientists and staff informed on past and future activities at ICTP and initiatives in their home countries. The text may be reproduced freely with due credit to the source.

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ICTP Public Information OfficeStrada Costiera, 11I-34151 Trieste Italy [email protected]

ISSN 2222-6923

Kip Thorne Delivers ICTP Colloquium

2018 ICTP/ICO Prize Winner Urbasi Sinha Promoting Quantum Science and Technology in India

A Conversation with Alan Guth

2017 Dirac Medal Ceremony Honours Three Quantum Science Pioneers

Research Highlights

ICTP News Briefs

Alumni News

In Memoriam

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News from ICTP:145

Contents

Cover photo: Students from Palestine and Morocco visited ICTP's SciFabLab in April to learn how to use and code for 3D printers and other tools, with the goal of opening fabrication laboratories at their home institutes. The students were here thanks to a collaboration between ICTP, the Sunshine4Palestine non-governmental organization, and the Young Minds section of the European Physical Society.

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From winning a physics Nobel prize to developing the concept for a Hollywood blockbuster film, theoretical physicist Kip Thorne’s expertise and enthusiasm for astrophysics has captured the minds and imaginations of millions. His research in gravitational waves contributed to their detection by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015, and he lent his scientific credentials as a consultant for the 2014 film Interstellar.

On Thursday 24 May, Professor Thorne brought his brand of science excitement to ICTP, where he delivered a colloquium on Geometrodynamics: The Nonlinear Dynamics of Curved Spacetime. His talk centered on a challenge posed 50 years ago by his doctoral supervisor, John Wheeler, to explore geometrodynamics--understanding gravitation through fluctuations in geometry--by asking, how does the curvature of spacetime behave when roiled in a storm; like a storm at sea with crashing waves? “We tried to explore this and failed. Success eluded us until two new tools became available: computer simulations, and gravitational wave observations,” the

Features

Kip Thorne Delivers ICTP Colloquium

talk’s abstract outlines. Thorne described what these have begun to teach us, and offered a vision for the future of geometrodynamics.

Professor Thorne is currently the Feynman Professor of Theoretical Physics, Emeritus at the California Institute of Technology (Caltech). He was cofounder (with Rainer Weiss and Ronald Drever) of the LIGO project. LIGO - in the hands of a younger generation of physicists - made the breakthrough discovery of gravitational waves arriving at Earth from the distant universe on 14 September 2015. For his contributions to LIGO and to gravitational wave research, Thorne shared the 2017 Nobel Prize in Physics with Rainer Weiss and Barry Barish. In 2009, Thorne stepped down from his Caltech professorship to ramp up a new career at the interface between art and science, including the movie Interstellar (which sprang from a treatment he co-authored, and for which he was executive producer and science advisor).

A video interview with Thorne is available on ICTP’s YouTube page.

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In India, she created and leads the country’s first laboratory dedicated to research in quantum optics, directing ground-breaking research in quantum information and computing. Her research achievements, combined with her active promotion of optics research to the general public, have earned Urbasi Sinha the 2018 International Commission for Optics(ICO)/ICTP Gallieno Denardo Award.

The optics prize is awarded annually to researchers younger than 40 years of age from a developing country who have made significant contributions to the field of optics or photonics. Sinha was presented with the award at a ceremony held at ICTP on 13 February, during the Centre’s annual Winter College on Optics.

At her Quantum Optics Laboratory based at the Raman Research Institute in Bengaluru, India, Sinha has been investigating new frontiers in the world of quantum optics. Her experience in the field prepared her well for the pioneering role she now finds herself in. Educated at Cambridge, she spent several years at Canada’s Institute for Quantum Computing (IQC), where she was encouraged by IQC Founder and Director Raymond Laflamme (a student of Stephen Hawking) to perform experiments in IQC’s quantum optics lab. “I wanted to learn quantum optics by experimentation, and this was one of the best environments to do that in,” Sinha explained. One of her first experiments there was to test a key concept of quantum mechanics known as Born’s rule (a rule that predicts the probabilities for occurrence of events) but had, until then, never been explicitly tested. The results of that experiment, summarized in an article with Sinha as lead author and Laflamme and others as co-authors, proved the validity of Born’s Rule and received broad media coverage after it was published in Science magazine in 2010 (10.1126/science.1190545).

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2018 ICTP/ICO Prize Winner Urbasi Sinha Promoting Quantum Science

and Technology in India

Back in India, Sinha’s lab is pursuing several research lines, providing valuable hands-on experience to the many students who are keen to work with a scientist of Sinha’s international stature. “Quantum information is a very new area in India, especially experimental, and ours is one of the first modern labs to be dedicated to this field,” she said. One activity at the lab is investigating a higher dimensional system--a unit of quantum information--called a qutrit. “This is an alternative approach to trying to increase the number of qubits in a quantum computer, which is what most people are trying to do,” Sinha explained, referring to technology giants like IBM and Intel who are in a race to produce quantum computers with 50 qubits.

Other research lines include quantum entanglement and quantum key distribution. The latter, explained Sinha, will play an important role in information security once quantum computers become a reality. “The problem is that a quantum computer is going to be able to run an algorithm which can break the classical key distribution, called Shor’s Algorithm, that is used for encryption and decryption. So, we need a quantum answer to the question.”

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The Salam Distinguished Lecture Series is an annual tradition at ICTP, providing an opportunity for renowned scientists to showcase recent advances in their fields. The 2018 series featured cosmologist Alan Guth, a professor at MIT and an ICTP Dirac Medallist. Guth explored fundamental questions about the beginnings and structure of the universe in his ICTP talks.

In 1979, Guth was a post-doctoral researcher focusing not on cosmology but on particle physics. He was in his eighth year as a postdoc, struggling to find a job, when he heard two lectures by visiting cosmologists, one of which introduced him to the flatness problem. Our universe has no perceptible space-time curvature, hence it is ‘flat’, a situation that seemingly requires incredibly precise initial conditions. This leaves cosmologists to wonder how these initial conditions came to be so precisely fine-tuned. Guth was fascinated, even though it had little to do with his previous work. It seemed suspicious that such precise initial conditions would be just a coincidence.

Guth was soon drawn into cosmology and went on to develop the theory of inflation. This theory describes an exponential expansion-explosion of space from about 10-36 seconds to 10-33 seconds after the Big Bang, which accounts for the density distribution of the universe, the large-scale structure of the universe.

A Conversation with Alan Guth

Guth has continued to elaborate the theory of inflation and delve into other topics as a professor at MIT. His three Salam Distinguished Lectures covered the possibility of our universe being part of a multiverse, the implications of eternal inflation of the universe, and the possible origin of the arrow of time. Work by Guth and other physicists on eternal inflation has led to the idea of a multiverse, where space is full of patches, with physical properties differing in each. “In most versions of inflation theory, inflation is eternal into the future— it stops in places, but always continues in other places. Where inflation stops, universes form, which we call pocket universes,” Guth explains. Increasing amounts of data are helping refine theories of inflation, but Guth has said that it’s difficult to have a theory of inflation that does not lead to the existence of a multiverse.

Guth is still investigating the early universe in a variety of other ways. One of his lines of research is an exploration of primordial black holes, “which are black holes that could have formed immediately after the Big Bang,” Guth says. “We’re looking at a scenario where the black holes form directly as a consequence of the density perturbations created by inflation.” Not much is known about how black holes merge and evolve over time, but eventually, theories about primordial black holes could provide predictions about distributions and masses of observable black holes today, providing more clues to the development of the universe.

“The amazing thing about the current state of cosmology is both how much we know and how much we don’t know,” Guth says. “We know how to build inflationary models that make spectacular predictions for all the properties we can measure, like the measurements of the cosmic background radiation. Those measurements have grown more and more precise and still continue to fit perfectly with what simple models of inflation predict— I find that amazing.” Guth adds, “But at the same time, there are very fundamental things that we don’t understand, so there are some very important loose ends.”

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ICTP held its 2017 Dirac Medal Award Ceremony on 18 March 2018, honouring three pioneers in quantum sciences. Charles Bennett of the IBM Watson Research Center, David Deutsch of Oxford University, and Peter Shor of Massachusetts Institute of Technology were recognized for their groundbreaking work in applying fundamental concepts of quantum mechanics to solving basic problems in computation and communication, bringing together the fields of quantum mechanics, computer science, and information theory.

Four decades ago, Charles Bennett independently invented and carefully analyzed what is now known as reversible classical computation, proving that classical computation can in principle be performed without consumption of energy. With Gilles Brassard (University of Montreal), Bennett invented quantum cryptography, where two distant parties share a secret encryption key, with security from eavesdroppers guaranteed by the basic quantum limitations on measurements of incompatible observables.

David Deutsch is one of the founding fathers of quantum computing. He introduced the notion of a quantum Turing machine that would operate on arbitrary superpositions of states (that is, on qubits),

2017 Dirac Medal Ceremony Honours Three Quantum Science Pioneers

the concept of the quantum logic gate and quantum circuit, as well as the network model of quantum computations. He showed that all possible operations on a quantum computer could be generated by combining sequences of a single kind of three-qubit logic gate. (Later, Bennett, Shor and coworkers showed that sequences of one-qubit gates and one simple type of reversible classical two-bit gates sufficed.)

Peter Shor boosted the field of quantum computation by designing efficient quantum algorithms for factoring large numbers and computing discrete logarithms, each of which can be used to break classical encryption schemes. He thus proved that a quantum computer could solve a useful, hard computational problem exponentially faster than any known classical computer algorithm. Shor also introduced quantum error-correcting codes and fault-tolerant quantum computation, which are schemes for coping with the effects of stray interactions (noise) disturbing qubits.

ICTP’s Dirac Medal is announced annually on Dirac’s birthday, 8 August, to scientists who have made significant contributions to theoretical physics. For more details about the prize and a list of past winners, visit the Dirac Medal web page.

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ICTP researcher Federico Bernardini, in collaboration with an international team, have identified the world’s oldest lizard, providing key insight into the evolution of modern lizards and snakes. Their research appeared on the cover of the 30 May issue of Nature (doi.org/10.1038/s41586-018-0093-3).

The 240-million-year-old fossil, Megachirella wachtleri, was originally found 20 years ago in the Dolomite Mountains, a UNESCO World Heritage Site in Northern Italy. Researchers originally thought it was linked to—but not an ancestor of—modern lizards and snakes. Further analysis by an international team of researchers determined the specimen was actually the oldest relative ever found of all living lizards and snakes, shaking up the evolutionary family tree of reptiles and shedding new light on the survivors of the most devastating mass extinction the world has ever faced.

The fossil was analyzed using high-resolution computer tomography at the ICTP Multidisciplinary Lab and Elettra synchrotron facility in Trieste. The three-dimensional digital images obtained allowed the researchers to look through the rock, at parts of the skeleton that were previously inaccessible, without damaging this unique fossil. This revealed a whole new suite of anatomical features that place Megachirella in a different and much more interesting light, indicating that it was actually older than previously estimated by at least 10 million years.

Research Team Including ICTP

Uncovers World’s Oldest Lizard

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Research Highlights

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A team of physicists from ICTP and IQOQI-Innsbruck has come up with a surprisingly simple idea to investigate quantum entanglement of many particles. Instead of digging deep into the properties of quantum wave functions--which are notoriously hard to experimentally access--they propose to realize physical systems governed by the corresponding entanglement Hamiltonians. By doing so, entanglement properties of the original problem of interest become accessible via well-established tools. This radically new approach could help to improve understanding of quantum matter and open the way to new quantum technologies.

The team comprised ICTP researcher Marcello Dalmonte (who also works closely with SISSA), along with Peter Zoller and Benoît Vermersch from the Department of Theoretical Physics at the University of Innsbruck and the Institute of Quantum Optics and Quantum Information (IQOQI) of the Austrian Academy of Sciences. Their research, titled Quantum Simulation and Spectroscopy of Entanglement Hamiltonians, appeared in Nature Physics (doi: 10.1038/s41567-018-0151-7).

Quantum entanglement forms the heart of the second quantum revolution. It is a key characteristic used to understand forms of quantum matter, and a key resource for present and future quantum technologies.

Turning Entanglement Upside Down

A New Form of Water

Water is liquid. Indeed, this is true at ambient conditions, as experienced in our daily life. But what would happen under extreme pressures and temperatures such as those inside planets rich in water like Uranus or Neptune? According to scientists, a new phase would appear, a form of water both liquid and solid: a “superionic” water. A team of researchers at ICTP and SISSA, among which Sandro Scandolo and Erio Tosatti, already theoretically predicted this almost 20 years ago in a study published in Science in 1999. Their paper was recently cited by a research team from Lawrence Livermore National Laboratory (LLNL), the University of California, Berkeley and the University of Rochester, which has provided the first experimental evidence for the existence of superionic water. A recent note about the study, featured in Nature Physics, was posted by the New York Times last week.

“It’s the first time scientists have managed to recreate such extreme conditions in a lab, the only conditions under which to observe superionic water,” said Scandolo. He added, “Most of the credit for this result goes to the incredible technological development of recent years and to the cutting-edge facilities exploited. The confirmation of the existence of this form of water validates the theoretical and computational tools used to predict it.”

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ICTP Launches New Podcast

ICTP has launched a podcast! It’s called SciVibes, and it is now online for you to listen to. This podcast brings you casual conversations with global scientists, fascinating chats that happen at coffee breaks and in the corridors with some of the thousands of scientists that visit ICTP every year.

The coming conversations with scientists will involve roman roads, paleoclimate techniques, career paths, the philosophy of science, scientific capacity building, and quantum computing, among many other subjects.

You can find SciVibes on Soundcloud, iTunes, and Stitcher, and can listen to each episode on ICTP’s website atictp.it/scivibes.

Physics Without Frontiers in Kabul

ICTP’s Physics Without Frontiers programme has visited many places in the world, many multiple times as they gradually build communities and networks of scientists. In April, the programme visited Afghanistan for the first time, meeting with over 400 eager students in Kabul at Kabul University. An international team of PWF scientists collaborated with local scientists and students to organize two days of a high-level workshop in particle physics and cosmology, with a third day of outreach activities.

ICTP News Briefs

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‘Friends of ICTP’ to Strengthen Bonds Amongst ICTP Community

Since its opening in 1964, ICTP has hosted more than 180,000 visits of scientists coming from 188 countries. To promote a bond of friendship and connections within this unique network, ICTP is happy to announce its support of ‘Friends of ICTP’, an association created to aid ICTP and its mission by developing international relationships through dialogue and cooperation among scientists.

Run by volunteers who have been associated with ICTP, Friends of ICTP strives to keep the spirit of ICTP founder Abdus Salam alive, through activities ranging from networking to mentoring to offering a helping hand to visitors new to ICTP.

More information is available on the Friends of ICTP website (https://friendsofictp.org/).

ICTP, KFAS Renew Commitment to Science

ICTP and the Kuwait Foundation for the Advancement of Sciences (KFAS) have renewed an agreement to provide support for scientists from Kuwait and the Arab world to participate in ICTP activities.

ICTP Director Fernando Quevedo and KFAS Director General Dr. Adnan Shihab-Eldin made the agreement official in a signing ceremony at ICTP on 31 January. The renewed partnership continues KFAS support for ICTP postdoctoral fellowships, as well as for Arab students who have been accepted into the Centre’s Postgraduate Diploma Programme and for scientists from Arab countries to attend ICTP conferences and workshops. KFAS has also agreed to continue its sponsorship of ICTP’s annual Salam Distinguished Lectures Series. In addition, the two institutes agreed to expand the partnership to new activities related to scientific capacity building and teacher training.

ICTP News Briefs

Friends of ICTP President Joseph Niemela (left) with ICTP Director Fernando Quevedo at the signing of an agreement between the two organizations

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The Future of Quantum Technologies

A new kind of computing is on the horizon, one that could greatly shift the way complex problems are solved. Quantum computing, which until very recently was only theoretical, is slowly becoming a reality, promising a future of unprecedented computing speed. Major computer manufacturers such as IBM, along with search engine giant Google, are already producing quantum computing chips that will someday drive a quantum machine. Quantum computing and technologies were the main topics of a public roundtable hosted by ICTP and SISSA on 14 March, honouring the work of its 2017 Dirac Medallists who received their awards at a ceremony earlier that day. The public roundtable featured three key players in quantum computing:

◃ Hartmut Neven, Google’s Director of Engineering

◃ Alessandro Curioni, IBM Fellow, Vice President of IBM Europe and Director of the IBM Research Lab in Zurich

◃ Tommaso Calarco, Director, Institute for Complex Quantum Systems, University of Ulm and member of the expert group for the European Commission’s Quantum Technology Flagship

Salam Spirit Awardees Announced

The family of ICTP founder and Nobel Laureate Abdus Salam has revealed the winners of the 2018 Spirit of Abdus Salam Award. Announced annually on 29 January—Abdus Salam’s birthday—the award recognizes those who, like Salam himself, have worked tirelessly to promote the development of science and technology in disadvantaged parts of the world.

This year’s Spirit of Abdus Salam Award recipients are Victor Latorre and Alberto Verjovsky. LaTorre, a physicist from Peru, served on the Centre’s Scientific Council as its first member from South America. His activities in his home country have influenced hundreds of Peruvian science students. Verjovsky is a mathematician from Mexico who has been highly influential in the development of mathematics there. He enjoyed a close working relationship with ICTP founder Abdus Salam, and convinced him that ICTP should establish a section in mathematics.

ICTP News Briefs

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Malik Maaza, from Algeria and a regular ICTP Associate, has been awarded the prestigious African Union Kwame Nkrumah Award for Scientific Excellence (AUKNASE) 2017, a major recognition at a continental level for his pioneering work in science and technology and for his contribution in science for African development. Professor Maaza has pioneered and implemented numerous continental and national initiatives, including the Nanosciences African Network (NANOAFNET) launched jointly with ICTP and TWAS.

Marlon Brenes of Costa Rica, a 2016 graduate of the joint ICTP-SISSA Master in High Performance Computing (MHPC) programme, recently published new research in the prestigious journal Physical Review Letters together with ICTP researchers Marcello Dalmonte and Antonello Scardicchio (https://doi.org/10.1103/PhysRevLett.120.030601). The article is titled “Many-Body Localization Dynamics from Gauge Invariance”.

Postgraduate Diploma Programme alumnus William Ugalde has been elected as head of the School of Mathematics at the University of Costa Rica.

Alumni News

Postgraduate Diploma Programme alumnus Mostafa Hamouda has published a paper in the journal Climate Dynamics (https://doi.org/10.1007/s00382-018-4169-4). The paper, titled “Ekman pumping mechanism driving precipitation anomalies in response to equatorial heating”, was based on research he pursued with ICTP climatologist Fred Kucharski.

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Stanislas Ouaro, professor of mathematics and a former ICTP Junior Associate from 2003 to 2010, has been appointed Ministre de l’Education Nationale et de l’Alphabétisation of his country, Burkina Faso, earlier this year. Professor Ouaro obtained his PhD at Université de Ouagadougou in 2001. He has visited ICTP since 1999 as a participant in training activities, both in mathematics and in climate modeling. He also spent research periods with ICTP’s Mathematics section in 2005, 2006 and 2009 and has collaborated with ICTP frequently since then. In 2012, he was appointed president of Université Ouaga II, in Gonse, Burkina Faso.

Ayesha Asloob Qureshi, a former postdoctoral fellow in ICTP’s Mathematics section, is one of the first recipients of the Abdus Salam Medal (ASM) of the National Mathematical Society of Pakistan (NMSP). Qureshi, who was at ICTP from 2013 to 2014, is currently an assistant professor at Sabanci University, Turkey, working in the area of commutative algebra. Qureshi was cited by the selection committee for “her remarkable papers published in good journals with a high impact on combinatorial commutative algebra. The concepts and ideas introduced by Qureshi continue to give rise to new and interesting developments in our field.”

Jehan Akbar, an ICTP Junior Associate and former TRIL fellow, has been awarded substantial research funding by the Pakistani government for a project on “Analysis and characterization of advanced materials, chemical and biological samples using optical and photothermal spectroscopy”. The project includes the establishment of the first optical (photothermal) spectroscopy laboratory in Pakistan.

Former ICTP postdocs Anton Mellit from Ukraine and Erik Carlsson from the United States have published an article titled “A proof of the shuffle conjecture” (DOI: https://doi.org/10.1090/jams/893) in one of the most prestigious journals in mathematics, the Journal of the American Mathematical Society (JAMS).

Alumni News

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GianCarlo GhirardiProfessor Ghirardi was associated with ICTP for many years as a researcher, a professor, and as the head of its Associateships and Federation

Scheme. He attended the first-ever international seminar in theoretical physics in Trieste that was organized by ICTP co-founders Paolo Budinich

and Abdus Salam in the early 1960s and had been a steady presence at the centre ever since. Ghirardi is well known for his contributions to the

foundations of quantum mechanics, as well as for his research, teaching and efforts to promote

and develop physics. He was one of three authors of the so-called GRW theory.

Stephen HawkingThe March passing of Stephen Hawking was

keenly felt at ICTP, where many of his theories are studied. Director Fernando Quevedo is a colleague of Hawking at Cambridge’s Department of Applied Mathematics and

Theoretical Physics as a professor of theoretical physics there. “Knowing, seeing

and interacting with Stephen have been some of the most extraordinary experiences in my

life. He was an exceptional human being, and I feel so fortunate to have had the opportunity to

meet him,” said Quevedo.

George SudarshanTheoretical physicist E. C. George Sudarshan

was the recipient, together with Nicola Cabibbo, of ICTP’s 2010 Dirac Medal, for fundamental contributions to the understanding of weak interactions and other aspects of theoretical

physics. He discovered (with Robert Marshak) the V-A theory of weak interactions, which opened

the way to the full description of the unified electroweak theory. The V-A theory was crucial to the work on the unification of the weak and

electromagnetic interactions by Steven Weinberg, Abdus Salam and Sheldon Glashow, for which the

three received the 1979 Nobel Prize in Physics.

Joseph PolchinskiJoseph Polchinski, a prominent theoretical physicist and longtime friend of ICTP, was a

professor at the Kavli Institute for Theoretical Physics at the University of California, Santa

Barbara. His great contributions to theoretical physics, including the discovery of D-branes

–– a type of membrane in string theory –– have led to advances in the understanding of string

theory and quantum gravity. In 2008, he shared ICTP’s Dirac Medal with Juan Maldacena and

Cumrun Vafa for their fundamental contributions to superstring theory.

In Memoriam

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Credits

EditorMary Ann Williams

Scientific Editor/ Direttore responsabile Sandro Scandolo

Statistician Giuliana Gamboz

WritersKelsey CalhounAnna Lombardi

Photos Roberto BarnabàICTP Photo ArchivesGianCarlo Ghirardi photo: Marino SterleJoseph Polchinski photo:Massimo Silvano

DesignJordan Chatwin

Printed byArt Group Graphics s.r.l.

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