We use Picard-Lefschetz theory to prove a new formula for intersection numbers of twisted
cocycles associated with a given arrangement of hyperplanes. In a special case when this …

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 We revisit the relations between open and closed string scattering amplitudes
discovered by Kawai, Lewellen, and Tye (KLT). We show that they emerge from the un …

A bstract We introduce a natural generalization of the scattering equations, which connect
the space of Mandelstam invariants to that of points on ℂℙ 1, to higher-dimensional …

A bstract Perturbiner expansion provides a generating function for all Berends-Giele
currents in a given quantum field theory. We apply this method to various effective field …

A bstract We further elaborate on the general construction proposed in [1], which connects,
via tree-level double copy, massless string amplitudes with color-ordered QFT amplitudes …

We present a twistorlike formula for the complete tree-level S matrix of six-dimensional
(6D)(2, 0) supergravity coupled to 21 Abelian tensor multiplets. This is the low-energy …

A bstract We propose new formulae for the two-loop n-point D-dimensional integrands of
scattering amplitudes in Yang-Mills theory and gravity. The loop integrands are written as a …

A bstract In this work we have studied the Kleiss-Kuijf relations for the recently introduced
Parke-Taylor factors at one-loop in the CHY approach, that reproduce quadratic Feynman …

A bstract In this paper we reconsider the Cachazo-He-Yuan construction (CHY) of the so
called scattering amplitudes at one-loop, in order to obtain quadratic propagators. In …