Landau Singularities and Hexagon Functions

Landau conditions tell us about the possible branch points of Feynman integrals and have been around for many decades. More recently, the program of obtaining integrated results for scattering amplitudes in N=4 super-Yang-Mills theory has relied on ansatze for an algebraic quantity called the "symbol," which is designed to capture the branch cut structure of transcendental functions. In this talk, I will review the Landau analysis at one loop and use it to begin to understand geometrically the quantities that are seen in the symbol of hexagon integrals and six-particle remainder/ratio functions.