This thesis proposes a new perspective on scattering amplitudes in quantum field theories.
Their standard formulation in terms of sums over Feynman diagrams is replaced by a …

A bstract The scattering equations provide a powerful framework for the study of scattering
amplitudes in a variety of theories. Their derivation from ambitwistor string theory led to …

This report is centred around tree-level scattering amplitudes in pure Yang–Mills theories,
the most prominent example is given by the tree-level gluon amplitudes of QCD. I will …

We explain a procedure to manifest the Bern–Carrasco–Johansson duality between color
and kinematics in n-point one-loop amplitudes of a variety of supersymmetric gauge …

A bstract We introduce a bosonic ambitwistor string theory in AdS space. Even though the
theory is anomalous at the quantum level, one can nevertheless use it in the classical limit to …

A bstract We prove that the scattering equation formalism for Yang-Mills amplitudes can be
used to make manifest the theory's color-kinematics duality. This is achieved through a …

A bstract We continue our investigation of Z-theory, the second double-copy component of
open-string tree-level interactions besides super-Yang-Mills (sYM). We show that the …

A bstract As described by Cachazo, He and Yuan, scattering amplitudes in many quantum
field theories can be represented as integrals that are fully localized on solutions to the so …

A bstract We present new relations for scattering amplitudes of color ordered gluons and
gravitons in Einstein-Yang-Mills theory. Tree-level amplitudes of arbitrary multiplicities and …

A bstract We present all-multiplicity evidence that the tree-level S-matrix of gluons and
gravitons in heterotic string theory can be reduced to color-ordered single-trace amplitudes …