High Energy Physics

Quantum field theory intertwines continuous and discrete structures. On the discrete side, combinatorics plays a central role in describing and understanding its expansions and models. This lecture series focuses on the combinatorial aspects of quantum field theory. In the first part, we explore analytic combinatorics techniques, inspired by QFT, for the enumeration of graphs. These methods turn out to be surprisingly powerful in addressing deep questions in algebraic geometry, topology, and statistical models on graphs. In the second part, we turn to discrete structures arising in perturbative expansions of QFT. We study these from a modern combinatorics viewpoint, using tools such as Lorentzian polynomials and generalized permutahedra to better understand the mathematical objects at the heart of quantum field theory. For updates visit: https://michaelborinsky.com/combqft.html This course is offered by the University of Waterloo's Department of Combinatorics & Optimization; UW students can enroll through Quest. Lectures will be held at Perimeter Institute, 31 Caroline St N, Waterloo. Students will need to sign in and out of Perimeter each day. Note room change on Sept 25 and Oct 2, and no classes week of October 13.

Charting the Future Symposium: Big questions in particle physics, strong gravity, and cosmology over the next 25 years

Join us for a special symposium celebrating Perimeter’s 25th anniversary. This event offers a unique opportunity to unite Perimeter alumni and friends in the fields of cosmology, particle physics, and strong gravity with our extended community, reflect on a quarter-century of discovery, and look ahead to the challenges and opportunities that will shape the next 25 years of fundamental physics.

Over the past quarter-century, we have witnessed transformative advances across our fields. In particle physics, the discovery of the Higgs boson crowned decades of effort, while precision experiments continue to probe the Standard Model and search for new physics. In strong gravity, the direct detection of gravitational waves has opened a new observational window onto black holes, neutron stars, and the very fabric of spacetime. In cosmology, precision measurements of the cosmic microwave background and large-scale structure have revolutionized our understanding of the universe’s origins and evolution, even as dark matter and dark energy remain profound mysteries.

As we look to the future, a new generation of experiments, observations, and theoretical ideas promises to drive further revolutions. From uncovering physics beyond the Standard Model to probing the nature of spacetime and the earliest moments of the cosmos, the next 25 years are poised to be as transformative as the last.

This symposium will bring together leading researchers, young scientists, alumni, and friends to celebrate past achievements, and imagine the discoveries yet to come. We invite you to be part of this landmark event at Perimeter Institute, as we honor the spirit of curiosity, ambition, and collaboration that has defined our journey so far — and will carry us forward.

 

Invited Speakers

• Haipeng An (Tsinghua University)
• Masha Baryakhtar (University of Washington)
• Brian Batell (University of Pittsburgh)
• Laura Bernard (Observatoire de Paris)
• Richard Bond (CITA)
• Pablo Bosch Gomez (Utrecht University)
• Latham Boyle (University of Edinburgh)
• Patrick Brady (University of Wisconsin-Milwaukee)
• Joe Bramante (Queen's University)
• Savas Dimopoulos (Perimeter Institute)
• Adrienne Erickcek (University of North Carolina at Chapel Hill)
• Stefania Gori (UC Santa Cruz)
• Chad Hanna (Pennsylvania State)
• Renée Hložek (University of Toronto)
• Yoni Kahn (University of Toronto)
• Vicky Kaspi (McGill University)
• Gordan Krnjaic (Fermilab)
• Ian Low (Northwestern University)
• Mathew Madhavacheril (University of Pennsylvania)
• David Morissey (TRIUMF)
• Moritz Münchmeyer (University of Wisconsin-Madison)
• Ue-Li Pen (CITA, Perimeter Institute)
• Will Percival (Perimeter Institute)
• Maxim Pospelov (University of Minnesota)
• Josef Pradler (Austrian Academy of Sciences)
• Daniel Siegel (University of Greifswald)
• Nils Siemonsen (Princeton University)
• Carlos Wagner (University of Chicago)
• Huan Yang (Tsinghua University)
• Matias Zaldarriaga (IAS)

 

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Organizing Committee
Asimina Arvanitaki
Luis Lehner
Sergey Sibiryakov
Kendrick Smith

Detector operators, of which the average null energy operator provides the most famous example, arise as direct theoretical models of asymptotic measurements in collider experiments. In QFT, detector operators are expressed in terms of "light-ray operators", whose correlation functions provide an interesting class of non-perturbatively well-defined observables. There has recently been renewed interest in detector operators coming from three distinct directions: In CFTs, there has been progress understanding the space of light-ray operators, their organization into Regge trajectories, and their appearance in Lorentzian operator product expansions. In perturbative QFT and gravity, borrowing techniques from the study of scattering amplitudes, there has been progress understanding multi-point correlation functions of detector operators, in particular, their function space and singularities. Finally, in particle physics, there have recently been direct measurements of correlation functions of detector operators in collider experiments, enabling measurements of their scaling behavior and the structure of multi-point correlators of light-ray operators in QCD. In this mini-course I will give an introduction to the theory of light-ray/ detector operators, their correlators, and their applications in particle phenomenology, and provide an overview of the recent progress in the directions mentioned above. Throughout, I will attempt to highlight the different perspectives and motivations for studying these operators, coming from the CFT, amplitudes and phenomenological communities. I will conclude with a discussion of open problems in both theory and phenomenological applications, as well as highlighting areas where theoretical developments could have an impact on real world applications at colliders. Join live sessions via Zoom link: https://pitp.zoom.us/j/96935592330?pwd=NNtf7839TThLFEWIzdH7fYxNYksyYr.1 View all past talks on PIRSA: https://pirsa.org/c25035

We will cover the basics of the gauge/gravity duality, including some of the following aspects: holographic fluids, applications to condensed matter systems, entanglement entropy, and recent advances in understanding the black hole information paradox. Instructor: David Kubiznak/Gang Xu Students who are not part of the PSI MSc program should review enrollment and course format information here: https://perimeterinstitute.ca/graduate-courses

Constructing a theory of quantum gravity, and with it a notion of quantum spacetime is one of the biggest challenges faced by modern theoretical physics. This workshop will bring together researchers from a wide range of viewpoints and give them an opportunity to exchange ideas and gain new insights.

The workshop is supported by the Simons Foundation.

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Workshop Speakers

Marcela Carena (Perimeter Institute)
Astrid Eichhorn (Universität Heidelberg)
Netta Englehardt (MIT)
Johanna Erdmenger (University of Würzburg)
Gulia Gubitosi (University of Naples Federico II)
Renate Loll (Radboud University)
Jessica Muir (Perimeter Institute)
A.W. Peet (University of Toronto)
Alessia Platania (University of Copenhagen)
Jocelyn Read (California State University, Fullerton)
Kasia Rejzner (York University)
Mairi Sakellariadou (King's College London)
Sarah Shandera (Pennsylvania State University)
Sumati Surya (Raman Research Institute)
Karen Yeats (University of Waterloo)

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Scientific Organizers
Bianca Dittrich (Perimeter Institute)
Sabrina Pasterski (Perimeter Institute)
Céline Zwikel (Perimeter Institute)
Sruthi Narayanan (Perimeter Institute)

The course will cover the basics of conformal field theories and also some applications, including exact computations of the critical exponents in 2d statistical models. Instructor: Jaume Gomis/Mykola Semenyakin Students who are not part of the PSI MSc program should review enrollment and course format information here: https://perimeterinstitute.ca/graduate-courses

The Standard Model of particle physics is introduced, and reviewed, from a modern effective field theory perspective. Instructor: Seyda Ipek/Gang Xu Students who are not part of the PSI MSc program should review enrollment and course format information here: https://perimeterinstitute.ca/graduate-courses

This course introduces the functional integral formalism, the renormalization group, and non-abelian gauge theory. Additional topics may be covered as time allows. Instructor: Francois David / Gang Xu Students who are not part of the PSI MSc program should review enrollment and course format information here: https://perimeterinstitute.ca/graduate-courses

The first half of the course explains why fields are desirable when quantum mechanics meets special relativity. The second half introduces different kinds of spinor fields and their interactions. Instructor: Gang Xu Students who are not part of the PSI MSc program should review enrollment and course format information here: https://perimeterinstitute.ca/graduate-courses

Pedro will lead a mini-course (no credit) at Perimeter Institute. To express your interest in attending please complete this registration form (https://forms.office.com/r/nDQ6SDxSR4) by noon on Thursday, October 3. Pedro has selected 9 papers for this mini-course. -Infrared Photons and Gravitons by Weinberg, 1965 -Determination of an Operator Algebra for the 2D Ising Model by Kadanoff and Ceva, 1971 -Confinement of Quarks by Wilson, 1974, -Phenomenological Lagrangians by Weinberg, 1979, -Gravitational Effects on and of Vacuum Decay by Coleman and De Luccia, 1980 -Classical and Quantum Gravity Effects from Planckian Energy Superstring Collisions by Amati, Ciafaloni and Veneziano, 1987 -Quantum Spin Chains and The Haldane Gap by Affleck, 1988 -The Large N Limit of SFTs and Supergravity by Maldacena, 1997 -Entanglement Entropy and Quantum Field Theory by Calabrese and Cardy, 2008 If you think there are super nice papers that are missing that could be better than some of these in a particular topic please contact Pedro directly (pvieira@perimeterinstitute.ca). The format will be: A] Pedro will give a 1h30m lecture about one of these papers on a Monday or a Friday (the Monday or Friday right after B] unless there is a holiday) B] One week later, X students give a presentation of Y minutes about important recent papers that refer/are related to that paper. At the end of this lecture we give feedback about those presentations. What is X and what is Y depends on how many students volunteer to present. Of course, people who just want to attend without presenting are also most welcome! Location: Alice Room, 3rd Floor, Perimeter Institute, 31 Caroline St N, Waterloo Recording/Zoom Details: Lectures will be recorded for PIRSA; Zoom link will be provided to registered participants. Building Access: Participants who do not have an access card for Perimeter Institute must sign in at the security desk before each session. When attending the lectures you can use the free self-serve coffee/water station on the ground floor. Meals and snacks at the on-site Black Hole Bistro are available at the full menu cost.

Perimeter Institute is happy to host the inaugural summer school for the Simons Collaboration on Celestial Holography July 22-26 in Waterloo, ON. The program will feature lectures on background material relevant for graduate students and postdocs interested in this emerging subfield, paired with vision talks on exciting future research directions.

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