The S-matrix in quantum field theory is used to do exactly this.

The S-matrix in quantum field theory is an example of a time-ordered product.

In doing so he was led to introduce a unitary "characteristic" S-matrix.

The most widely used expression for the S-matrix is the Dyson series.

Note that this theorem only constrains the symmetries of the S-matrix itself.

Heisenberg proposed to study the S-matrix directly, without any assumptions about space-time structure.

This technique is also known as the S-Matrix.

Heisenberg proposed to use unitarity to determine the S-matrix.

In 1937, he introduced the S-matrix, which became an indispensable tool in particle physics.

The S-matrix is the quantity that describes how a superposition of incoming particles turn into outgoing ones.

The linear combination is given by a matrix known as the S-matrix, which encodes all information about the possible interactions between particles.

In the 1940s Werner Heisenberg developed, independently, the idea of the S-matrix.

This is nowadays known not to be true, since there are many theories which are nonperturbatively consistent, each with their own S-matrix.

S-matrix by the means of network analyzer (electrical)

The transition amplitude is then given as the matrix element of the S-matrix between the initial and the final states of the quantum system.

Branch cuts of the S-matrix in the complex-energy plane are associated to the opening of a scattering channel.

In both cases, the perturbative calculation of the S-matrix leads to Feynman diagrams.

Poles of the S-matrix in the complex-energy plane are identified with bound states, virtual states or resonances.

Relativity : The S-matrix is a representation of the Poincaré group.

The theorem provides a test for a given S-matrix to determine whether or not it can be constructed as a lossless rational two-port network.

It avoided the notion of space and time by replacing it with abstract mathematical properties of the S-matrix.

It uses the scattering matrix (S-matrix) technique to join different sections of the waveguide or to model nonuniform structures.

The S-matrix is more symmetric under relativity than the Hamiltonian, because it does not require a choice of time slices to define.

The Initial and Final States of the interaction relate through the so-called scattering matrix (S-matrix).

The dispersion relations were analytic properties of the S-matrix, and they were more stringent conditions than those that follow from unitarity alone.