Solving Infinite Families of Dual Conformal Integrals and Periods

Abstract: We compute infinite families of all-loop planar, dual conformal invariant (DCI) integrals, which contribute to four-point Coulomb-branch amplitudes and correlators in ${\cal N}=4$ supersymmetric Yang-Mills theory, by solving boxing" differential equations via package HyperlogProcedures; this amounts to aninverse-boxing" operation/integration recursively acting on lower-loop cases (with the box integral as the starting point), and the resulting single-valued harmonic polylogarithmic functions (SVHPL) are nicely labeled by binary" strings of $0$ and $1$ without consecutive $1$'s. These functions are special cases of the so-called generalized ladders studied in arXiv:1207.3824, where extended Steinmann relations are imposed due to planarity, and they are counted by the Fibonacci sequence. Our results can be viewed astwo-dimensional" extensions of the well-known ladder integrals to many more infinite families of DCI integrals: the ladders have strings with a single $1$ followed by all $0$'s, and the other extreme, which nicely evaluate to the zigzag" SVHPL functions with alternating $1$'s and $0$'s, are nothing but the four-point DCI integrals from the very special family of anti-prism $f$-graphs. We also study periods of these integrals: while their periods are in general complicated single-valued multiple zeta values (SVMZV), thezigzag" DCI integrals from anti-prism gives exactly the famous ``zigzag" periods proportional to $\zeta_{2L{+}1}$, and empirically it provides a numerical lower-bound for $L$-loop periods of any binary string, with the upper-bound given by that of the ladder. Based on $f$-graphs as a tool for studying these periods, we discuss several interesting facts and observations about these (motivic) SVMZV and relations among them to all loops, and enumerate a basis for them up to $L=10$.