Nima Arkani-Hamed is a theorist with wide-ranging interests in fundamental physics, working at the Institute for Advanced Study in Princeton, NJ. He is concerned with the relationship between theory and experiment, with a special focus on current and future particle accelerators as well as cosmological observations.

Mathieu Giroux is a Ph.D. student at McGill University in Montréal, Canada. He earned a bachelor's degree in mathematics and physics, as well as a master's degree in physics from the same institution. He is interested in the formal aspects of quantum field theories, aiming to streamline computational methods.

Holmfridur Sigridar Hannesdottir is a member of the School of Natural Sciences at the Institute for Advanced Study in Princeton, NJ. She received a Ph.D. in physics from Harvard University, after completing a [...]. in physics from the University of Iceland. Her work focuses on theoretical aspects of quantum field theories, including the study of infrared divergences in gauge theories and constraining the analytic structure of Feynman integrals.

Sebastian Mizera is a postdoctoral researcher at Princeton University and a visiting scholar at the Institute for Advanced Study in Princeton, NJ. His work focuses on the foundations of scattering amplitudes.

Celina Pasiecznik is a Ph.D. student at McGill University in Montréal, Canada. She earned her bachelor's degree in physics from the University of Toronto, followed by master's degrees in mathematical physics from the University of Oxford and in aeronautics and astronautics from MIT. Celina's research now focuses on high-energy particle physics, particularly on scattering amplitudes involving gravitons.

Tasty bits of several complex variables.- Scattering on periodic lattices.- Dispersion relation in QCD.- Schwinger Keldysh formalism.- Boundary view on analyticity.- Observables in expanding universes.- The analytic S-matrix revisited.- A timeless history of time.- Gravitational physics from scattering amplitudes.