Numerical data for scattering amplitudes of Goldstone bosons in d=4 obtained by solving various optimisation problems. The data is stored in .m files. Mathematica notebook is provided for loading and plotting the data. ...
In this thesis, we study gapless Quantum Field Theories using S-matrix bootstrap methods. These methods are intrinsically nonperturbative and utilize basic physical principles---such as Lorentz invariance, unitarity, and crossing symmetry---to constrain th ...
We study 2-to-2 scattering amplitudes of massless spin one particles in d = 4 space-time dimensions, like real world photons. We define a set of non-perturbative observables (Wilson coefficients) which describe these amplitudes at low energies. We use full ...
We review the basic assumptions and spell out the detailed arguments that lead to the bound on the Regge growth of gravitational scattering amplitudes. The minimal extra ingredient compared to the gapped case - in addition to unitarity, analyticity, subexp ...
We explore the space of meromorphic amplitudes with extra constraints coming from the shape of the leading Regge trajectory. This information comes in two guises: it bounds the maximal spin of exchanged particles of a given mass; it leads to sum rules obey ...
