Browsing by Author "Moerman, Robert"

Now showing items 1-8 of 8

    • Boundaries of the Amplituhedron with amplituhedronBoundaries 

      Lukowski, Tomasz; Moerman, Robert (2021-02-01)
      Positive geometries provide a modern approach for computing scattering amplitudes in a variety of physical models. In order to facilitate the exploration of these new geometric methods, we introduce a MATHEMATICA package ...

    • From Momentum Amplituhedron Boundaries to Amplitude Singularities and Back 

      Ferro, Livia; Lukowski, Tomasz; Moerman, Robert (2020-07-28)
      The momentum amplituhedron is a positive geometry encoding tree-level scattering amplitudes in $\mathcal{N}=4$ super Yang-Mills directly in spinor-helicity space. In this paper we classify all boundaries of the momentum ...

    • Grass(mannian) trees and forests: Variations of the exponential formula, with applications to the momentum amplituhedron 

      Moerman, Robert; Williams, Lauren K. (2023-03-15)
      The Exponential Formula allows one to enumerate any class of combinatorial objects built by choosing a set of connected components and placing a structure on each connected component which depends only on its size. There ...

    • The Grassmannian for celestial superamplitudes 

      Ferro, Livia; Moerman, Robert (2021-11-25)
      Recently, scattering amplitudes in four-dimensional Minkowski spacetime have been interpreted as conformal correlation functions on the two-dimensional celestial sphere, the so-called celestial amplitudes. In this note we ...

    • Kleiss-Kuijf relations from momentum amplituhedron geometry 

      Damgaard, David; Ferro, Livia; Lukowski, Tomasz; Moerman, Robert (2021-07-16)
      Abstract: In recent years, it has been understood that color-ordered scattering amplitudes can be encoded as logarithmic differential forms on positive geometries. In particular, amplitudes in maximally supersymmetric ...

    • Momentum Amplituhedron meets Kinematic Associahedron 

      Damgaard, David; Ferro, Livia; Lukowski, Tomasz; Moerman, Robert (2021-02-03)
      In this paper we study a relation between two positive geometries: the momen- tum amplituhedron, relevant for tree-level scattering amplitudes in N = 4 super Yang-Mills theory, and the kinematic associahedron, encoding ...

    • On the geometry of the orthogonal momentum amplituhedron 

      Łukowski, Tomasz; Moerman, Robert; Stalknecht, Jonah (2022-12-01)
      In this paper we focus on the orthogonal momentum amplituhedron Ok, a recently introduced positive geometry that encodes the tree-level scattering amplitudes in ABJM theory. We generate the full boundary stratification of ...

    • Pushforwards via scattering equations with applications to positive geometries 

      Łukowski, Tomasz; Moerman, Robert; Stalknecht, Jonah (2022-10-03)
      In this paper we explore and expand the connection between two modern descriptions of scattering amplitudes, the CHY formalism and the framework of positive geometries, facilitated by the scattering equations. For theories ...