The conformal bootstrap is a non-perturbative method to constrain and solve conformal field theories.
Unlike more traditional techniques of quantum field theory, conformal bootstrap does not use the Lagrangian of the theory. Instead, it operates with the general axiomatic parameters, such as the scaling dimensions of the local operators and their operator product expansion coefficients. A key axiom is that the product of local operators must be expressible as a sum over local operators (thus turning the product into an algebra); the sum must have a non-zero radius of convergence.
The main ideas of the conformal bootstrap were formulated in the 1970s by the Soviet physicist Alexander Polyakov and the Italian physicists Sergio Ferrara, and Aurelio Grillo.
In two dimensions, the conformal bootstrap was demonstrated to work in 1983 by Alexander Belavin, Alexander Polyakov and Alexander Zamolodchikov. Many two-dimensional conformal field theories were solved using this method, notably the minimal models and the Liouville field theory.
In higher dimensions, the conformal bootstrap started to develop following the 2008 paper by Riccardo Rattazzi, , Erik Tonni and Alessandro Vichi. The method was since used to obtain many general results about conformal and superconformal field theories in three, four, five and six dimensions. Applied to the conformal field theory describing the critical point of the three-dimensional Ising model, it produced the world's most precise predictions for its critical exponents.