Opening Session and information from organizers

• Frank Wilczek (Stockholm University)

Room: Fåhraeus salen

Bell inequalities: From Curiosity to Security

• Artur Ekert

Room: Fåhraeus salen Bell inequalities's journey from rags to riches of quantum theory was a long one. Proposed by John Bell in 1964, the inequalities were designed to check whether quantum theory, with its inherent statistical predictions, is a complete description of physical reality or whether it is just a provisional construct, with an underlying hidden structure which, once discovered, would offer precise predictions. The subsequent pioneering experiments of outliers, such as John Clauser (1972) and Alain Aspect (1982), showed that Bell's inequalities can be violated. However, these experiments were barely noticed at that time. Quantum theory is admittedly strange, but it worked and the research community just carried on using it in an instrumental way, making successful statistical predictions while avoiding anything related to their interpretations. Bell inequalities were viewed as a philosophical topic with no practical value and hence not worthy of the attention of serious scientists. When Bell inequalities snagged my imagination, I was just a PhD student with nothing to lose. In 1991, I reformulated Bell inequalities as the test for eavesdropping in cryptography, paving the way for the most secure communication systems to date, known as the device independent quantum key distribution. The new narrative around Bell inequalities created an additional motivation to close all possible loopholes in the previous experiments. In the new context it seemed reasonable. Nature would have to be very malicious if it were to cheat selectively; on locality in some experiments and exploring detection loopholes in some others. In contrast, an eavesdropper has all the rights to be malicious. Closing the loopholes posed an experimental challenge but gradually, due to the efforts of several experimental groups, to mention only those of Ronald Hansen (2015) and Anton Zeilinger (2015), the loopholes were closed (albeit not all of them in the same experiment) and device independent cryptography became a realistic experimental proposition. Cryptography offered a lifeline to quantum foundations and in return the experimental tools developed to pursue esoteric philosophical questions gave cryptography unprecedented security. The curiosity and perseverance of the few brave souls who made this happen (and who are still alive) were finally rewarded with the 2022 Nobel Prize in Physics.

Bell inequalities: From Curiosity to Security

• Artur Ekert

Room: Fåhraeus salen Bell inequalities's journey from rags to riches of quantum theory was a long one. Proposed by John Bell in 1964, the inequalities were designed to check whether quantum theory, with its inherent statistical predictions, is a complete description of physical reality or whether it is just a provisional construct, with an underlying hidden structure which, once discovered, would offer precise predictions. The subsequent pioneering experiments of outliers, such as John Clauser (1972) and Alain Aspect (1982), showed that Bell's inequalities can be violated. However, these experiments were barely noticed at that time. Quantum theory is admittedly strange, but it worked and the research community just carried on using it in an instrumental way, making successful statistical predictions while avoiding anything related to their interpretations. Bell inequalities were viewed as a philosophical topic with no practical value and hence not worthy of the attention of serious scientists. When Bell inequalities snagged my imagination, I was just a PhD student with nothing to lose. In 1991, I reformulated Bell inequalities as the test for eavesdropping in cryptography, paving the way for the most secure communication systems to date, known as the device independent quantum key distribution. The new narrative around Bell inequalities created an additional motivation to close all possible loopholes in the previous experiments. In the new context it seemed reasonable. Nature would have to be very malicious if it were to cheat selectively; on locality in some experiments and exploring detection loopholes in some others. In contrast, an eavesdropper has all the rights to be malicious. Closing the loopholes posed an experimental challenge but gradually, due to the efforts of several experimental groups, to mention only those of Ronald Hansen (2015) and Anton Zeilinger (2015), the loopholes were closed (albeit not all of them in the same experiment) and device independent cryptography became a realistic experimental proposition. Cryptography offered a lifeline to quantum foundations and in return the experimental tools developed to pursue esoteric philosophical questions gave cryptography unprecedented security. The curiosity and perseverance of the few brave souls who made this happen (and who are still alive) were finally rewarded with the 2022 Nobel Prize in Physics.

The doped-atom toolbox for quantum simulation and computation

• Andrew Fisher

Room: Fåhraeus salen I will describe the developing experimental tools of atomically controlled defect implantation in semiconductors using scanning tunneling microscopy (STM) lithography and how the resulting nanostructures can be used to implement a range of controlled quantum systems within the material. I will cover applications both in quantum computation (including the initialization and readout of qubits and the implementation of universal sets of unitary gates) and in the realization/simulation of archetypal models in condensed matter physics (including disordered quantum transport, the Mott transition, and topologically non-trivial insulators in one and two dimensions). I will compare this dopant-based toolbox with other techniques and give some outlooks for future development.

The doped-atom toolbox for quantum simulation and computation

• Andrew Fisher

Room: Fåhraeus salen

QCD Matter in Collisions of Heavy Ions

• Barbara Jacak

Room: Fåhraeus salen Heavy ion collisions reproduce droplets of the trillions-of-degrees-hot liquid that filled the microseconds-old universe, called quark-gluon plasma (QGP). Experiments at RHIC and the LHC have gathered extensive data about this plasma, showing that it flows with very low viscosity per particle and that it is very opaque to colored probes. I will show how we can measure and understand the dynamics of this complex many-body system, and extract transport properties of QCD matter from the data. Experimental observables we study include collective flows, electromagnetic radiation, and the effect of interactions with plasma on hard probes such as heavy quarks and jets. Jet substructure offers a particularly promising way to map the evolution of quarks and gluons to the hadrons seen in detectors. I will also discuss how the future Electron-Ion Collider will probe QCD in the cold, dense gluonic matter in the heart of nuclei.

QCD Matter in Collisions of Heavy Ions

• Barbara Jacak

Room: Fåhraeus salen Heavy ion collisions reproduce droplets of the trillions-of-degrees-hot liquid that filled the microseconds-old universe, called quark-gluon plasma (QGP). Experiments at RHIC and the LHC have gathered extensive data about this plasma, showing that it flows with very low viscosity per particle and that it is very opaque to colored probes. I will show how we can measure and understand the dynamics of this complex many-body system, and extract transport properties of QCD matter from the data. Experimental observables we study include collective flows, electromagnetic radiation, and the effect of interactions with plasma on hard probes such as heavy quarks and jets. Jet substructure offers a particularly promising way to map the evolution of quarks and gluons to the hadrons seen in detectors. I will also discuss how the future Electron-Ion Collider will probe QCD in the cold, dense gluonic matter in the heart of nuclei.

General quantum measurements

• Andrew Jordan (Chapman University)

Room: Fåhraeus salen This survey series of lectures on quantum measurement starts with textbook quantum measurement followed by the von Neumann model for measurement as a physical process. The discussion will transition into the theory of weak measurement in the very weak coupling limit. Generalized measurement is then characterized by imperfect correlation between system and meter, and describable with positive operators. Motivating physical examples will be given.

Continuous measurements: diffusion and jumps

• Andrew Jordan (Chapman University)

Room: Fåhraeus salen Repeated weak measurements give rise to a stochastic process. I will introduce both diffusive and quantum jump trajectories of monitored quantum systems. Physical realizations of continuous monitoring will be given, motivating the mathematical description of quantum state collapse as a stochastic differential equation or stochastic path integral. Comparisons with experimental data will be discussed.

Adventures in Lattice Fermions: Many-Body Scars and the Schwinger Model

• Igor Klebanov

Room: Fåhraeus salen

Adventures in Lattice Fermions: Many-Body Scars and the Schwinger Model

• Igor Klebanov

Room: Fåhraeus salen

T symmetry and its violation: Fundamentals

• Frank Wilczek (Stockholm University)

Room: Fåhraeus salen The study of time-reversal symmetry (T) has played a major role in the history of physics and is central to several frontier of research today. In this series of lectures, I will review the foundations of our current understanding and then both critique and build on that understanding. The series will have four parts. In Part 1 I will introduce basic concepts in increasingly rich contexts, building up to the standard model, where I’ll demonstrate the great result that approximate T symmetry is a “semi-accidental” consequence of deeper principles. In Part 2 I will expose a very specific and profound limitation of that result, connected to quantum anomalies. Closing that loophole leads us to suggest the existence of a new kind of particle, the axion, which has become a leading candidate to provide the dark matter of the universe and is presently inspiring many investigations. In the third part I will discuss phenomenological implications of T in physics, including applications both to fundamental physics and to materials. In the fourth part I will discuss how and in what sense biology breaks spatial parity P at the molecular level, and pose the analogous questions for T.

T symmetry and its violation: Anomalies and Axions

• Frank Wilczek (Stockholm University)

Room: Fåhraeus salen The study of time-reversal symmetry (T) has played a major role in the history of physics and is central to several frontier of research today. In this series of lectures, I will review the foundations of our current understanding and then both critique and build on that understanding. The series will have four parts. In Part 1 I will introduce basic concepts in increasingly rich contexts, building up to the standard model, where I’ll demonstrate the great result that approximate T symmetry is a “semi-accidental” consequence of deeper principles. In Part 2 I will expose a very specific and profound limitation of that result, connected to quantum anomalies. Closing that loophole leads us to suggest the existence of a new kind of particle, the axion, which has become a leading candidate to provide the dark matter of the universe and is presently inspiring many investigations. In the third part I will discuss phenomenological implications of T in physics, including applications both to fundamental physics and to materials. In the fourth part I will discuss how and in what sense biology breaks spatial parity P at the molecular level, and pose the analogous questions for T.

Bell inequalities: From Curiosity to Security

• Artur Ekert (University of Oxford, Okinawa Institute of Science and Technology Graduate University, National University of Singapore)

Room: Fåhraeus salen Bell inequalities's journey from rags to riches of quantum theory was a long one. Proposed by John Bell in 1964, the inequalities were designed to check whether quantum theory, with its inherent statistical predictions, is a complete description of physical reality or whether it is just a provisional construct, with an underlying hidden structure which, once discovered, would offer precise predictions. The subsequent pioneering experiments of outliers, such as John Clauser (1972) and Alain Aspect (1982), showed that Bell's inequalities can be violated. However, these experiments were barely noticed at that time. Quantum theory is admittedly strange, but it worked and the research community just carried on using it in an instrumental way, making successful statistical predictions while avoiding anything related to their interpretations. Bell inequalities were viewed as a philosophical topic with no practical value and hence not worthy of the attention of serious scientists. When Bell inequalities snagged my imagination, I was just a PhD student with nothing to lose. In 1991, I reformulated Bell inequalities as the test for eavesdropping in cryptography, paving the way for the most secure communication systems to date, known as the device independent quantum key distribution. The new narrative around Bell inequalities created an additional motivation to close all possible loopholes in the previous experiments. In the new context it seemed reasonable. Nature would have to be very malicious if it were to cheat selectively; on locality in some experiments and exploring detection loopholes in some others. In contrast, an eavesdropper has all the rights to be malicious. Closing the loopholes posed an experimental challenge but gradually, due to the efforts of several experimental groups, to mention only those of Ronald Hansen (2015) and Anton Zeilinger (2015), the loopholes were closed (albeit not all of them in the same experiment) and device independent cryptography became a realistic experimental proposition. Cryptography offered a lifeline to quantum foundations and in return the experimental tools developed to pursue esoteric philosophical questions gave cryptography unprecedented security. The curiosity and perseverance of the few brave souls who made this happen (and who are still alive) were finally rewarded with the 2022 Nobel Prize in Physics.

Bell inequalities: From Curiosity to Security

• Artur Ekert

Room: Fåhraeus salen Bell inequalities's journey from rags to riches of quantum theory was a long one. Proposed by John Bell in 1964, the inequalities were designed to check whether quantum theory, with its inherent statistical predictions, is a complete description of physical reality or whether it is just a provisional construct, with an underlying hidden structure which, once discovered, would offer precise predictions. The subsequent pioneering experiments of outliers, such as John Clauser (1972) and Alain Aspect (1982), showed that Bell's inequalities can be violated. However, these experiments were barely noticed at that time. Quantum theory is admittedly strange, but it worked and the research community just carried on using it in an instrumental way, making successful statistical predictions while avoiding anything related to their interpretations. Bell inequalities were viewed as a philosophical topic with no practical value and hence not worthy of the attention of serious scientists. When Bell inequalities snagged my imagination, I was just a PhD student with nothing to lose. In 1991, I reformulated Bell inequalities as the test for eavesdropping in cryptography, paving the way for the most secure communication systems to date, known as the device independent quantum key distribution. The new narrative around Bell inequalities created an additional motivation to close all possible loopholes in the previous experiments. In the new context it seemed reasonable. Nature would have to be very malicious if it were to cheat selectively; on locality in some experiments and exploring detection loopholes in some others. In contrast, an eavesdropper has all the rights to be malicious. Closing the loopholes posed an experimental challenge but gradually, due to the efforts of several experimental groups, to mention only those of Ronald Hansen (2015) and Anton Zeilinger (2015), the loopholes were closed (albeit not all of them in the same experiment) and device independent cryptography became a realistic experimental proposition. Cryptography offered a lifeline to quantum foundations and in return the experimental tools developed to pursue esoteric philosophical questions gave cryptography unprecedented security. The curiosity and perseverance of the few brave souls who made this happen (and who are still alive) were finally rewarded with the 2022 Nobel Prize in Physics.

The doped-atom toolbox for quantum simulation and computation

• Andrew Fisher

Room: Fåhraeus salen

The doped-atom toolbox for quantum simulation and computation

• Andrew Fisher

Room: Fåhraeus salen

Emergent Axion response in metamaterials

• Maxim Gorlach

Room: Fåhraeus salen

Quantum amplification and linear detectors

• Andrew Jordan (Chapman University)

Room: Fåhraeus salen Quantum physics allows amplification, but puts stringent requirements on how the amplification can be carried out. Beginning with theoretical preliminaries of how much noise a quantum limited amplifier must add to the measured signal, I will overview the linear response theory of detectors, and give examples of amplifier designs in superconducting circuits.

Measurement related phenomena and applications

• Andrew Jordan (Chapman University)

Room: Fåhraeus salen The last lecture will survey some of the fascinating phenomena associated with quantum measurement. These include the possibility of reversing a weak measurement, entanglement of distant objects by a joint measurement process, and feedback control of continuously monitored quantum systems.

Adventures in Lattice Fermions: Many-Body Scars and the Schwinger Model

• Igor Klebanov

Room: Fåhraeus salen

Adventures in Lattice Fermions: Many-Body Scars and the Schwinger Model

• Igor Klebanov

Room: Fåhraeus salen

T symmetry and its violation: Applications in physics

• Frank Wilczek (Stockholm University)

Room: Fåhraeus salen The study of time-reversal symmetry (T) has played a major role in the history of physics and is central to several frontier of research today. In this series of lectures, I will review the foundations of our current understanding and then both critique and build on that understanding. The series will have four parts. In Part 1 I will introduce basic concepts in increasingly rich contexts, building up to the standard model, where I’ll demonstrate the great result that approximate T symmetry is a “semi-accidental” consequence of deeper principles. In Part 2 I will expose a very specific and profound limitation of that result, connected to quantum anomalies. Closing that loophole leads us to suggest the existence of a new kind of particle, the axion, which has become a leading candidate to provide the dark matter of the universe and is presently inspiring many investigations. In the third part I will discuss phenomenological implications of T in physics, including applications both to fundamental physics and to materials. In the fourth part I will discuss how and in what sense biology breaks spatial parity P at the molecular level, and pose the analogous questions for T.

T symmetry and it's violation: P and T in biology

• Frank Wilczek (Stockholm University)

Room: Fåhraeus salen The study of time-reversal symmetry (T) has played a major role in the history of physics and is central to several frontier of research today. In this series of lectures, I will review the foundations of our current understanding and then both critique and build on that understanding. The series will have four parts. In Part 1 I will introduce basic concepts in increasingly rich contexts, building up to the standard model, where I’ll demonstrate the great result that approximate T symmetry is a “semi-accidental” consequence of deeper principles. In Part 2 I will expose a very specific and profound limitation of that result, connected to quantum anomalies. Closing that loophole leads us to suggest the existence of a new kind of particle, the axion, which has become a leading candidate to provide the dark matter of the universe and is presently inspiring many investigations. In the third part I will discuss phenomenological implications of T in physics, including applications both to fundamental physics and to materials. In the fourth part I will discuss how and in what sense biology breaks spatial parity P at the molecular level, and pose the analogous questions for T.

Programmable Quantum Simulators

• Peter Zoller

Room: Fåhraeus salen

Programmable Quantum Simulators

• Peter Zoller

Room: Fåhraeus salen

QCD Matter in Collisions of Heavy Ions

• Barbara Jacak

Room: Fåhraeus salen Heavy ion collisions reproduce droplets of the trillions-of-degrees-hot liquid that filled the microseconds-old universe, called quark-gluon plasma (QGP). Over the past twenty years, data obtained via recreating this primordial fluid have shown that it is the most liquid liquid in the universe, making it the first complex matter to form as well as the source of all protons and neutrons. After a look at what we have learned about the formation and properties of this original liquid from heavy ion collisions, I will focus on the road ahead. I will frame questions that motivate experimental measurements coming soon, including: How does liquid QGP change as it is doped with an excess of quarks over antiquarks? Is there a critical point in the region of the QCD phase diagram as a function of temperature and doping that heavy ion collisions can explore? How does a strongly coupled liquid emerge, given that what you will see if you can probe QGP with high resolution is weakly coupled quarks and gluons? How can we use jets to see the inner workings of QGP and answer this question?

QCD Matter in Collisions of Heavy Ions

• Barbara Jacak

Room: Fåhraeus salen Heavy ion collisions reproduce droplets of the trillions-of-degrees-hot liquid that filled the microseconds-old universe, called quark-gluon plasma (QGP). Over the past twenty years, data obtained via recreating this primordial fluid have shown that it is the most liquid liquid in the universe, making it the first complex matter to form as well as the source of all protons and neutrons. After a look at what we have learned about the formation and properties of this original liquid from heavy ion collisions, I will focus on the road ahead. I will frame questions that motivate experimental measurements coming soon, including: How does liquid QGP change as it is doped with an excess of quarks over antiquarks? Is there a critical point in the region of the QCD phase diagram as a function of temperature and doping that heavy ion collisions can explore? How does a strongly coupled liquid emerge, given that what you will see if you can probe QGP with high resolution is weakly coupled quarks and gluons? How can we use jets to see the inner workings of QGP and answer this question?

Eigenstate Thermalization, Interlinking and the Emergence of Classical Physics in Quantum Theory

• Martin Greiter

Room: Fåhraeus salen

Eigenstate Thermalization, Interlinking and the Emergence of Classical Physics in Quantum Theory

• Martin Greiter

Room: Fåhraeus salen

T symmetry and it's violation: P and T in biology

• Frank Wilczek

Room: Fåhraeus salen The study of time-reversal symmetry (T) has played a major role in the history of physics and is central to several frontier of research today. In this series of lectures, I will review the foundations of our current understanding and then both critique and build on that understanding. The series will have four parts. In Part 1 I will introduce basic concepts in increasingly rich contexts, building up to the standard model, where I’ll demonstrate the great result that approximate T symmetry is a “semi-accidental” consequence of deeper principles. In Part 2 I will expose a very specific and profound limitation of that result, connected to quantum anomalies. Closing that loophole leads us to suggest the existence of a new kind of particle, the axion, which has become a leading candidate to provide the dark matter of the universe and is presently inspiring many investigations. In the third part I will discuss phenomenological implications of T in physics, including applications both to fundamental physics and to materials. In the fourth part I will discuss how and in what sense biology breaks spatial parity P at the molecular level, and pose the analogous questions for T.

Programmable Quantum Simulators

• Peter Zoller

Room: Fåhraeus salen

Doping and Probing the Original Liquid

• Krishna Rajagopal

Room: Fåhraeus salen

Doping and Probing the Original Liquid

• Krishna Rajagopal

Room: Fåhraeus salen

Introduction to Scattering Amplitudes

• David Kosower

Room: Fåhraeus salen I will present a brief introduction to modern methods for computing scattering amplitudes. I will cover the basics of spinor kinematics and construction of three-point amplitudes. I will also discuss color decomposition. I will discussion factorization and present the Britto-Cachazo-Feng-Witten on-shell recursion relations. Time permitting, I will also present a brief glimpse of the unitarity method.

Introduction to Scattering Amplitudes

• David Kosower

Room: Fåhraeus salen I will present a brief introduction to modern methods for computing scattering amplitudes. I will cover the basics of spinor kinematics and construction of three-point amplitudes. I will also discuss color decomposition. I will discussion factorization and present the Britto-Cachazo-Feng-Witten on-shell recursion relations. Time permitting, I will also present a brief glimpse of the unitarity method.

Introduction to Scattering Amplitudes

• David Kosower

Room: Fåhraeus salen

The Gravitational Double Copy and Spin

• Henrik Johansson

Room: Fåhraeus salen

The Gravitational Double Copy and Spin

• Henrik Johansson

Room: Fåhraeus salen

The Gravitational Double Copy and Spin

• Henrik Johansson

Room: Fåhraeus salen

Quantum Field Theory on the Lattice

• Zoltan Fodor

Room: Fåhraeus salen

Quantum Field Theory on the Lattice

• Zoltan Fodor

Room: Fåhraeus salen

Can standard quantum field theories have an ontological origin?

• Gerard 'tHooft

Room: Fåhraeus salen

Can standard quantum field theories have an ontological origin?

• Gerard 't Hooft

Room: Fåhraeus salen

Doping and Probing the Original Liquid

• Krishna Rajagopal

Room: Fåhraeus salen Heavy ion collisions reproduce droplets of the trillions-of-degrees-hot liquid that filled the microseconds-old universe, called quark-gluon plasma (QGP). Over the past twenty years, data obtained via recreating this primordial fluid have shown that it is the most liquid liquid in the universe, making it the first complex matter to form as well as the source of all protons and neutrons. After a look at what we have learned about the formation and properties of this original liquid from heavy ion collisions, I will focus on the road ahead. I will frame questions that motivate experimental measurements coming soon, including: How does liquid QGP change as it is doped with an excess of quarks over antiquarks? Is there a critical point in the region of the QCD phase diagram as a function of temperature and doping that heavy ion collisions can explore? How does a strongly coupled liquid emerge, given that what you will see if you can probe QGP with high resolution is weakly coupled quarks and gluons? How can we use jets to see the inner workings of QGP and answer this question?

Doping and Probing the Original Liquid

• Krishna Rajagopal

Room: Fåhraeus salen Heavy ion collisions reproduce droplets of the trillions-of-degrees-hot liquid that filled the microseconds-old universe, called quark-gluon plasma (QGP). Over the past twenty years, data obtained via recreating this primordial fluid have shown that it is the most liquid liquid in the universe, making it the first complex matter to form as well as the source of all protons and neutrons. After a look at what we have learned about the formation and properties of this original liquid from heavy ion collisions, I will focus on the road ahead. I will frame questions that motivate experimental measurements coming soon, including: How does liquid QGP change as it is doped with an excess of quarks over antiquarks? Is there a critical point in the region of the QCD phase diagram as a function of temperature and doping that heavy ion collisions can explore? How does a strongly coupled liquid emerge, given that what you will see if you can probe QGP with high resolution is weakly coupled quarks and gluons? How can we use jets to see the inner workings of QGP and answer this question?

Quantum Connections: from Hall Physics to Optics to Black Holes

• Smitha Vishveshwara

Room: Fåhraeus salen Time and again, one encounters marvelous unifying physics that links phenomena from the most miniscule to astronomical scales. This lecture set will explore one such direction that brings together fundamentals of quantum optics, quantum Hall physics, and certain aspects of black hole dynamics. We will first establish some of the basics of quantum Hall physics and associated lowest Landau levels, and the behavior of quasiparticles in this realm in the presence of a potential landscape. We will see some deep parallels between these descriptions, and quantum optical concepts, such as coherent states and squeezing. We will then see how such phenomena translate to Hawking radiation and black hole ringdown in the astronomical realm. Finally, we will build on these concepts to explore an intriguing quantum particle that differs from the fermion and boson---the anyon,--which has recently been observed and come into the limelight.

Quantum Connections: from Hall Physics to Optics to Black Holes

• Smitha Vishveshwara

Room: Fåhraeus salen Time and again, one encounters marvelous unifying physics that links phenomena from the most miniscule to astronomical scales. This lecture set will explore one such direction that brings together fundamentals of quantum optics, quantum Hall physics, and certain aspects of black hole dynamics. We will first establish some of the basics of quantum Hall physics and associated lowest Landau levels, and the behavior of quasiparticles in this realm in the presence of a potential landscape. We will see some deep parallels between these descriptions, and quantum optical concepts, such as coherent states and squeezing. We will then see how such phenomena translate to Hawking radiation and black hole ringdown in the astronomical realm. Finally, we will build on these concepts to explore an intriguing quantum particle that differs from the fermion and boson---the anyon,--which has recently been observed and come into the limelight.

Quantum Field Theory on the Lattice

• Zoltan Fodor

Room: Fåhraeus salen

Quantum Field Theory on the Lattice

• Zoltan Fodor

Room: Fåhraeus salen

Chiral symmetry and the Theta parameter

• Michael Creutz

Room: Fåhraeus salen

Lattice Fermions

• Michael Creutz

Room: Fåhraeus salen

Exploring new scientific frontiers using programmable atom arrays

• Mikhail Lukin

Room: Fåhraeus salen

Exploring new scientific frontiers using programmable atom arrays

• Mikhail Lukin

Room: Fåhraeus salen

QCD beyond perturbation theory

• Michael Creutz

Room: Fåhraeus salen

Real virtuality: Freedom and confinement

• Frank Wilczek (Stockholm University)

Room: Fåhraeus salen The contrast between (asymptotic) freedom and confinement was a source of great unease and some confusion in the early days of QCD. Some people still obsess over it. The degrees of freedom in which the theory is most naturally formulated, and that in a real sense become manifest at high energies or short distances – that is, quarks and gluons - are completely different from the degrees of freedom – that is, hadrons - that appear in the spectrum and the S matrix. How can such different descriptions coexist? In what sense can virtual particles be real physical entities? I will discuss how similar behavior arises in much simpler models than QCD – specifically, QED in 1 + 1 dimensions – where we can understand how it works in detail, both intuitively and mathematically. Along the way I will give a precise discussion of time-energy uncertainty, which is central to resolving the tension. I will also discuss some recent work using related ideas to suggest new observable phenomena in condensed matter physics. Following that (not very!) technical part of the presentation I will reminiscence briefly about my own experiences in the early days, and add some brief remarks about the status of QCD today and going forward.

How quantum chromodynamics took us by surprise

• Gerard ‘tHooft

Room: Fåhraeus salen

Fifty Years of Quantum Chromodynamics (The Theory of The Strong Nuclear Force)

• David Gross

Room: Fåhraeus salen

Closing Ceremony Room: Fåhraeus salen