6 papers
New Tools in the Landau Bootstrap
Piotr BargieÅa, Giulio Crisanti, Craig Larkin +4
We describe recent advances in our understanding of the analytic structure of Feynman integrals. In particular, we describe two new classes of constraints on such integrals, that i…
The spectrum of Feynman-integral geometries at two loops
Piotr Bargiela, Hjalte Frellesvig, Robin Marzucca +4
We provide a complete classification of the Feynman-integral geometries at two-loop order in four-dimensional Quantum Field Theory with standard quadratic propagators. Concretely,…
All-loop four-quark Bethe-Salpeter kernel
Piotr Bargiela
We analytically calculate the all-loop bare perturbative part of the four-quark Bethe-Salpeter kernel using modern scattering amplitude methods. We work to subleading order in the…
The integrand form of infrared singularities of two-loop QCD scattering amplitudes
Piotr Bargiela
In this work, we express the singular part of a scattering amplitude in terms of Feynman integrals compatible with topologies appearing in the bare amplitude, and we choose a basis…
On the finite basis of two-loop `t Hooft-Veltman Feynman integrals
Piotr Bargiela, Tong-Zhi Yang
In this work, we investigate the finite basis topologies of two-loop dimensionally regularized Feynman integrals in the `t Hooft-Veltman scheme in the Standard Model. We present a…
On the finite basis topologies for multi-loop high-multiplicity Feynman integrals
Piotr Bargiela, Tong-Zhi Yang
In this work, we systematically analyse Feynman integrals in the `t Hooft-Veltman scheme. We write an explicit reduction resulting from partial fractioning the high-multiplicity in…