A short, graduate-level synthesis of recent developments in theoretical physics, from a
pioneer in the field Lectures on the Infrared Structure of Gravity and Gauge Theory presents …

A bstract We systematically explore the space of scalar effective field theories (EFTs)
consistent with a Lorentz invariant and local S-matrix. To do so we define an EFT …

A bstract We explore the logarithmic terms in the soft theorem in four dimensions by
analyzing classical scattering with generic incoming and outgoing states and one loop …

We derive the first ever on-shell recursion relations applicable to effective field theories.
Based solely on factorization and the soft behavior of amplitudes, these recursion relations …

A bstract We derive a universal soft theorem for every scattering amplitude with at least one
massless particle in an arbitrary theory of scalars. Our results follow from the geometry of …

A bstract Classical subleading soft graviton theorem in four space-time dimensions
determines the gravitational wave-form at late and early retarded time, generated during a …

A bstract In [1], logarithmic correction to subleading soft photon and soft graviton theorems
have been derived in four spacetime dimensions from the ratio of IR-finite S-matrices. This …

A bstract It has been shown that in larger than four space-time dimensions, soft factors that
relate the amplitudes with a soft photon or graviton to amplitudes without the soft particle …

We show that the forward limit of tree-level scattering equations with two massive particles
yields the SL (2, C)-covariant form of the one-loop scattering equations recently proposed by …

A bstract Classical soft photon and soft graviton theorems determine long wavelength
electromagnetic and gravitational waveforms for a general classical scattering process in …