The purpose of this review is to bridge the gap between a standard course in quantum field
theory and recent fascinating developments in the studies of on-shell scattering amplitudes …

Here, we review the most recent progress in our understanding of quantum mechanical
observables in cosmology in the perturbative regime. It relies on an approach that considers …

Providing a comprehensive, pedagogical introduction to scattering amplitudes in gauge
theory and gravity, this book is ideal for graduate students and researchers. It offers a …

A bstract Perturbative scattering amplitudes in gauge theories have remarkable simplicity
and hidden infinite dimensional symmetries that are completely obscured in the …

Outlining a revolutionary reformulation of the foundations of perturbative quantum field
theory, this book is a self-contained and authoritative analysis of the application of this new …

A bstract Recent years have seen a surprising connection between the physics of scattering
amplitudes and a class of mathematical objects—the positive Grassmannian, positive loop …

A bstract This note addresses the problem of spurious poles in gauge-theoretic scattering
amplitudes. New twistor coordinates for the momenta are introduced, based on the concept …

We establish a direct connection between scattering amplitudes in planar four-dimensional
theories and a remarkable mathematical structure known as the positive Grassmannian. The …

A bstract Recently, an explicit, recursive formula for the all-loop integrand of planar
scattering amplitudes in\(\mathcal {N}={4}\) SYM has been described, generalizing the …

These lectures are a brief introduction to scattering amplitudes. We begin with a review of
basic kinematical concepts like the spinor helicity formalism, followed by a tutorial on …