9 papers
Multipositivity Constrains the Chiral Lagrangian
Clifford Cheung, Jaehoon Jeong, Pyungwon Ko +3
The chiral Lagrangian is a cornerstone of modern particle physics, offering a systematic and quantitative description of low-energy pions. Using tools from the modern scattering am…
The Equivalence Principle at High Energies Completes the Spectrum
Francesco Calisto, Clifford Cheung, Grant N. Remmen +2
We prove a version of the completeness hypothesis that follows from the coexistence of symmetry and gravity: tree-level gravitational scattering mandates single-particle states in…
Inverse Problem in Effective Field Theory
Francesco Calisto, Clifford Cheung, Grant N. Remmen +2
We show that the tree-level spectrum of heavy particles can be directly extracted from the Wilson coefficients of the corresponding effective field theory at low energies. This pro…
Completeness from Gravitational Scattering
Francesco Calisto, Clifford Cheung, Grant N. Remmen +2
We prove that symmetry in the presence of gravity implies a version of the completeness hypothesis. For a broad class of theories, we demonstrate that the existence of finitely man…
Strings from Almost Nothing
Clifford Cheung, Grant N. Remmen, Francesco Sciotti +1
We argue that string theory emerges inevitably from a few simple assumptions about physical scattering. Consistency alone requires that all tree-level four-point scattering amplitu…
Multipositivity Bounds for Scattering Amplitudes
Clifford Cheung, Grant N. Remmen
Lorentz invariance, unitarity, and causality enforce powerful constraints on the theory space of physical scattering amplitudes. However, virtually all efforts in this direction ha…