5 problems

Let ${\tt A}_n$ be the one-loop diagram with $n$ external legs and $n$ internal edges, and let ${\cal E}^{(0,0)}$ be the kinematic subspace where both internal and external masses…

Fix a number of external legs $\mathsf{n}$ and consider Feynman diagrams in the planar limit. Their first-type Landau singularities are the singularities obtained from the first-ty…

Let a scattering amplitude be viewed as a function of kinematic variables, and let $\Delta=0$ be a Landau singularity. A function is holonomic if it satisfies a holonomic system of…

PLD containment conjecture. For any Feynman diagram $G$ and any linear subspace ${\cal E}\subseteq{\cal K}$,

Case 4 polynomial-solution conjecture. The polynomial solutions for Case 4 are both necessary and sufficient for the Landau singularities; equivalently, the predicted singularities…