214 citations · 1.9k across the 30 of their papers we have counts for
29 papers · 1 filter
A KLT-like construction for multi-Regge amplitudes
Konstantin Baune, Johannes Broedel
Inspired by the calculational steps originally performed by Kawai, Lewellen and Tye, we decompose scattering amplitudes with single-valued coefficients obtained in the multi-Regge-…
Meromorphic modular forms and the three-loop equal-mass banana integral
Johannes Broedel, Claude Duhr, Nils Matthes
We consider a class of differential equations for multi-loop Feynman integrals which can be solved to all orders in dimensional regularisation in terms of iterated integrals of mer…
A geometrical framework for amplitude recursions: bridging between trees and loops
Johannes Broedel, André Kaderli
Various methods for the recursive evaluation of scattering amplitudes in quantum field theory and string theory have been put forward during the last couple of years. In these proc…
Two dialects for KZB equations: generating one-loop open-string integrals
Johannes Broedel, André Kaderli, Oliver Schlotterer
Two different constructions generating the low-energy expansion of genus-one configuration-space integrals appearing in one-loop open-string amplitudes have been put forward in \rc…
Amplitude recursions with an extra marked point
Johannes Broedel, Andre Kaderli
The recursive calculation of Selberg integrals by Aomoto and Terasoma using the Knizhnik-Zamolodchikov equation and the Drinfeld associator makes use of an auxiliary point and faci…
An analytic solution for the equal-mass banana graph
Johannes Broedel, Claude Duhr, Falko Dulat +3
We present fully analytic results for all master integrals for the three-loop banana graph with four equal and non-zero masses. The results are remarkably simple and all integrals…
Functional relations for elliptic polylogarithms
Johannes Broedel, Andre Kaderli
Numerous examples of functional relations for multiple polylogarithms are known. For elliptic polylogarithms, however, tools for the exploration of functional relations are availab…
Elliptic Feynman integrals and pure functions
Johannes Broedel, Claude Duhr, Falko Dulat +2
We propose a variant of elliptic multiple polylogarithms that have at most logarithmic singularities in all variables and satisfy a differential equation without homogeneous term.…
From modular forms to differential equations for Feynman integrals
Johannes Broedel, Claude Duhr, Falko Dulat +2
In these proceedings we discuss a representation for modular forms that is more suitable for their application to the calculation of Feynman integrals in the context of iterated in…
Elliptic symbol calculus: from elliptic polylogarithms to iterated integrals of Eisenstein series
Johannes Broedel, Claude Duhr, Falko Dulat +2
We present a generalization of the symbol calculus from ordinary multiple polylogarithms to their elliptic counterparts. Our formalism is based on a special case of a coaction on l…
From elliptic multiple zeta values to modular graph functions: open and closed strings at one loop
Johannes Broedel, Oliver Schlotterer, Federico Zerbini
We relate one-loop scattering amplitudes of massless open- and closed-string states at the level of their low-energy expansion. The modular graph functions resulting from integrati…
Elliptic polylogarithms and iterated integrals on elliptic curves I: general formalism
Johannes Broedel, Claude Duhr, Falko Dulat +1
We introduce a class of iterated integrals, defined through a set of linearly independent integration kernels on elliptic curves. As a direct generalisation of multiple polylogarit…
Twisted elliptic multiple zeta values and non-planar one-loop open-string amplitudes
Johannes Broedel, Nils Matthes, Gregor Richter +1
We consider a generalization of elliptic multiple zeta values, which we call twisted elliptic multiple zeta values. These arise as iterated integrals on an elliptic curve from whic…
Towards single-valued polylogarithms in two variables for the seven-point remainder function in multi-Regge-kinematics
Johannes Broedel, Martin Sprenger, Alejandro Torres Orjuela
We investigate single-valued polylogarithms in two complex variables, which are relevant for the seven-point remainder function in N=4 super-Yang-Mills theory in the multi-Regge re…
Six-point remainder function in multi-Regge-kinematics: an efficient approach in momentum space
Johannes Broedel, Martin Sprenger
Starting from the known all-order expressions for the BFKL eigenvalue and impact factor, we establish a formalism allowing the direct calculation of the six-point remainder functio…
Relations between elliptic multiple zeta values and a special derivation algebra
Johannes Broedel, Nils Matthes, Oliver Schlotterer
We investigate relations between elliptic multiple zeta values and describe a method to derive the number of indecomposable elements of given weight and length. Our method is based…
Elliptic multiple zeta values and one-loop superstring amplitudes
Johannes Broedel, Carlos R. Mafra, Nils Matthes +1
We investigate iterated integrals on an elliptic curve, which are a natural genus-one generalization of multiple polylogarithms. These iterated integrals coincide with the multiple…
Factorized soft graviton theorems at loop level
Johannes Broedel, Marius de Leeuw, Jan Plefka +1
We analyze the low-energy behavior of scattering amplitudes involving gravitons at loop level in four dimensions. The single-graviton soft limit is controlled by soft operators whi…
Constraining subleading soft gluon and graviton theorems
Johannes Broedel, Marius de Leeuw, Jan Plefka +1
We show that the form of the recently proposed subleading soft graviton and gluon theorems in any dimension are severely constrained by elementary arguments based on Poincaré and g…
Deformed one-loop amplitudes in N = 4 super-Yang-Mills theory
Johannes Broedel, Marius de Leeuw, Matteo Rosso
We investigate Yangian-invariant deformations of one-loop amplitudes in N = 4 super-Yang-Mills theory employing an algebraic representation of amplitudes. In this language, we repr…
A dictionary between R-operators, on-shell graphs and Yangian algebras
Johannes Broedel, Marius de Leeuw, Matteo Rosso
We translate between different formulations of Yangian invariants relevant for the computation of tree-level scattering amplitudes in N=4 super-Yang--Mills theory. While the R-oper…
On Yangian-invariant regularisation of deformed on-shell diagrams in N=4 super-Yang-Mills theory
Niklas Beisert, Johannes Broedel, Matteo Rosso
We investigate Yangian invariance of deformed on-shell diagrams with D=4, N=4 superconformal symmetry. We find that invariance implies a direct relationship between the deformation…
All order alpha'-expansion of superstring trees from the Drinfeld associator
Johannes Broedel, Oliver Schlotterer, Stephan Stieberger +1
We derive a recursive formula for the alpha'-expansion of superstring tree amplitudes involving any number N of massless open string states. String corrections to Yang-Mills field…
Polylogarithms, Multiple Zeta Values and Superstring Amplitudes
Johannes Broedel, Oliver Schlotterer, Stephan Stieberger
A formalism is provided to calculate tree amplitudes in open superstring theory for any multiplicity at any order in the inverse string tension. We point out that the underlying wo…