The SAGEX review on scattering amplitudes Chapter 9: Integrability of amplitudes in fishnet theories

Calculation of the Scattering Amplitudes

It is well known that the high order calculations of the observables within the perturbation theory has the serious difficulties (especially, if we take into account the polarization effects). Method of the direct calculation of amplitudes simplifies these calculations essentially. There is an even number (2N) of fermions in initial and final state for any reaction with Dirac particles. Therefo...

TASI Lectures on Scattering Amplitudes

Recursion Rules for Scattering Amplitudes in Non-Abelian Gauge Theories

We present a functional derivation of recursion rules for scattering amplitudes in a nonAbelian gauge theory in a form valid to arbitrary loop order. The tree-level and one-loop recursion rules are explicitly displayed. 1 Permanent address: Physics Department, Seoul National University, Seoul, 151-742, Korea. * e-mail: [email protected], [email protected]

Relating Scattering Amplitudes in Bosonic and Topological String Theories

A formal relationship between scattering amplitudes in critical bosonic string theory and correlation functions of operators in topological string theory is found. CTP #2080 March 1992 ⋆ This work is supported in part by funds provided by the U. S. Department of Energy (D.O.E.) under contract #DE-AC02-76ER03069. 1 At its essence, string theory is a locally reparametrization invariant theory in ...

Effective Field Theories from Soft Limits of Scattering Amplitudes.

We derive scalar effective field theories-Lagrangians, symmetries, and all-from on-shell scattering amplitudes constructed purely from Lorentz invariance, factorization, a fixed power counting order in derivatives, and a fixed order at which amplitudes vanish in the soft limit. These constraints leave free parameters in the amplitude which are the coupling constants of well-known theories: Namb...