Scattering Amplitudes across Germany
from
Tuesday, July 25, 2023 (3:00 PM)
to
Friday, July 28, 2023 (2:00 PM)
Monday, July 24, 2023
Tuesday, July 25, 2023
3:00 PM
Arrival of participants
Arrival of participants
3:00 PM  10:00 PM
Wednesday, July 26, 2023
9:00 AM
Registration
Registration
9:00 AM  9:20 AM
9:20 AM
Welcome

Lorenzo Tancredi
(TUM)
Nikolaos Syrrakos
(TUM)
Christoph Nega
(TUM)
Welcome
Lorenzo Tancredi
(TUM)
Nikolaos Syrrakos
(TUM)
Christoph Nega
(TUM)
9:20 AM  9:30 AM
Welcoming words and introduction to the workshop
9:30 AM
Nonfactorizable QCD corrections in hadron collider processes

Kirill Melnikov
Nonfactorizable QCD corrections in hadron collider processes
Kirill Melnikov
9:30 AM  10:30 AM
I will discuss the recent progress with describing the nonfactorizable QCD corrections to Higgs boson production in weak boson fusion and singletop production at the LHC, focusing on effects that arise beyond the leading eikonal approximation.
10:30 AM
Coffee Break
Coffee Break
10:30 AM  11:00 AM
11:00 AM
Integral reductions and computer algebra for amplitudes

Andreas von Manteuffel
Integral reductions and computer algebra for amplitudes
Andreas von Manteuffel
11:00 AM  12:00 PM
Integrationbyparts reductions of Feynman integrals and methods from computer algebra play an important role in the calculation of multiloop scattering amplitudes. In this talk, I will review modern methods based on finite field arithmetics and polynomial ideal theory.
12:00 PM
Lunch Break
Lunch Break
12:00 PM  2:00 PM
2:00 PM
Multiscale Amplitudes for Colliders: Tools and Perspectives

Ben Page
Multiscale Amplitudes for Colliders: Tools and Perspectives
Ben Page
2:00 PM  3:00 PM
In recent years, we have seen great progress in our ability to compute twoloop amplitudes describing the scattering of multiple particles. In this talk, we review the status of these calculations, the tools that made them possible as well as open questions and future directions.
3:00 PM
Analytic computation of 2loop scattering amplitudes for phenomenological applications

Ekta Chaubey
Analytic computation of 2loop scattering amplitudes for phenomenological applications
Ekta Chaubey
3:00 PM  4:00 PM
Analytic computation of multiloop Feynman integrals is crucial for the current era of precision physics. These analytic computations often bring us to intriguing algebraic structures which help in establishing deep connections with Mathematics. In this talk I will talk about some analytic computations of 2loop Feynman integrals with their phenomenological applications in mind.
4:00 PM
Coffee Break
Coffee Break
4:00 PM  4:30 PM
4:30 PM
Mathematical Structures in Massive Operator Matrix Elements and Wilson Coefficients

Johannes Blumlein
Mathematical Structures in Massive Operator Matrix Elements and Wilson Coefficients
Johannes Blumlein
4:30 PM  5:30 PM
tba
5:30 PM
IBP Reduction with Gröbner bases

Robin Bruser
IBP Reduction with Gröbner bases
Robin Bruser
5:30 PM  6:30 PM
In this talk we investigate how Gröbner bases theory can be used to perform integrationbyparts (IBP) reductions of loop integrals. The first part of the talk serves as brief introduction to Gröbner bases. In the second part we discuss the main idea on the example of oneloop bubble and oneloop box integrals. We see that the IBP relations form a left ideal in a rational doubleshift algebra. The IBP reduction of loop integrals then amounts to computing normal forms of shift operators of the rational doubleshift algebra with respect to a Gröbner basis of the left ideal. Finally, in the last part we discuss an ansatz based on linear algebra to simulate the computation of normal forms. This approach can be used for complicated problems, when obtaining the Gröbner basis is computationally too expensive.
7:00 PM
Dinner
Dinner
7:00 PM  8:30 PM
Thursday, July 27, 2023
9:30 AM
Canonical differential equations for sixpoint twoloop Feynman integrals

Julian Miczajka
Canonical differential equations for sixpoint twoloop Feynman integrals
Julian Miczajka
9:30 AM  10:30 AM
It is well known, that the problem of calculating a particular family of Feynman integrals can often be solved most efficiently by finding a basis of master integrals which satisfies a differential equation in socalled canonical form. In this talk, we discuss recent progress in finding such a canonical basis for two families of Feynman integrals with six external particles at two loops in an arbitrary number of spacetime dimensions. We also demonstrate how the resulting differential equation makes it straightforward to extract the identities that the integrals satisfy when the external kinematics lie in a fourdimensional space.
10:30 AM
Coffee Break
Coffee Break
10:30 AM  11:00 AM
11:00 AM
Feynman integrals, geometries and differential equations

Stefan Weinzierl
Feynman integrals, geometries and differential equations
Stefan Weinzierl
11:00 AM  12:00 PM
In this talk I will review recent developments in the field of analytical Feynman integral calculations. In particular, I will discuss Feynman integrals related to nontrivial geometries like an elliptic curve, or more general a CalabiYau manifold, and methods how to compute these Feynman integrals.
12:00 PM
Lunch Break
Lunch Break
12:00 PM  2:00 PM
2:00 PM
On extended topological quantum field theory

Ilka Brunner
On extended topological quantum field theory
Ilka Brunner
2:00 PM  3:00 PM
Topological quantum field theories (TQFT) are very simple models of quantum field theories. They allow for a mathematically rigorous definition and treatment. Physically, they are relevant since they describe subsectors of supersymmetric theories and also have applications in condensed matter. I will review some aspects of TQFT.
3:00 PM
The complex simplicity of cosmological correlators

Ivo Sachs
The complex simplicity of cosmological correlators
Ivo Sachs
3:00 PM  4:00 PM
I will review some aspects of the position space calulation of cosmological correlators in the inin formalism. In some cases they can be mapped to AdS correlators, by double Wick rotation, that are simpler than the compuation of the cosmological wave function.
4:00 PM
Coffee Break
Coffee Break
4:00 PM  5:00 PM
5:00 PM
Fishnet Amplitudes and Quantum Volumes of CalabiYau and Picard Varieties

Albrecht Klemm
Fishnet Amplitudes and Quantum Volumes of CalabiYau and Picard Varieties
Albrecht Klemm
5:00 PM  6:00 PM
2d conformal graphs can be drawn on the regular tilings of the plane. The corresponding amplitudes are solutions of the Yangian integrable symmetry operators convoluted with the symmetry group of the graph. To each graph we can associate a Calabi Yau variety defined by double or triple cover constructions. The latter case corresponds to the trivalent lattice and in this case the CalabiYau geometry is related to Picard varieties. The integrable structure implies flatness of the Gauss Manin connection of the geometry and amplitudes can be efficiently evaluated as the quantum volume of the associated geometries.
7:00 PM
Dinner
Dinner
7:00 PM  8:30 PM
Friday, July 28, 2023
9:30 AM
Scattering of spinning black holes at NNNLO

Jan Plefka
Scattering of spinning black holes at NNNLO
Jan Plefka
9:30 AM  10:30 AM
The need for high precision predictions of the general relativistic twobody problem for the future generation of gravitational wave detectors has opened a new window for the application of perturbative quantum field theory techniques to the domain of classical gravity. In this talk I will show how observables in the classical scattering of black holes and neutron stars can be efficiently computed in the postMinkowskian expansion using a worldline quantum field theory; thereby importing multiloop Feynman integration technology to this field. Here, the black holes or neutron stars are modelled as point particles in an effective field theory sense. Fascinatingly, the intrinsic spin of the black holes is captured by a supersymmetric extension of the worldline theory, enabling the computation of the far field waveform and scattering angle including spin to highest precision. With a view towards the audience I will sketch our recent stateoftheart NNNLO computation (4PM order) of KerrBlack Hole scattering and the challenges and opportunities ahead.
10:30 AM
Coffee Break
Coffee Break
10:30 AM  11:00 AM
11:00 AM
Symbol Alphabets from the Landau Singular Locus

Georgios Papathanasiou
Symbol Alphabets from the Landau Singular Locus
Georgios Papathanasiou
11:00 AM  12:00 PM
We provide evidence through two loops, that rational letters of polylogarithmic Feynman integrals are captured by the Landau equations, when the latter are recast as a polynomial of the kinematic variables of the integral, known as the principal Adeterminant. Focusing on one loop, we further show how to also obtain all nonrational letters with the help of Jacobi determinant identities. We verify our findings by explicitly constructing canonical differential equations and comparing with the existing literature, and finally extend the proof of the CohenMacauley property of oneloop integrals to a broader range of their kinematics.
12:00 PM
Lunch
Lunch
12:00 PM  2:00 PM