S-matrix
E9111
The S-matrix (scattering matrix) is a fundamental construct in quantum field theory that encodes the probabilities for transitions between initial and final particle states in scattering processes.
All labels observed (4)
| Label | Occurrences |
|---|---|
| S-matrix canonical | 8 |
| Dyson’s papers on the S-matrix in quantum electrodynamics | 1 |
| S-matrix theory | 1 |
| T-matrix | 1 |
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
concept in quantum field theory
ⓘ
operator ⓘ scattering matrix ⓘ |
| actsOn | asymptotic particle states ⓘ |
| appearsIn |
Standard Model
ⓘ
surface form:
standard model of particle physics
string theory scattering computations ⓘ |
| assumes | existence of asymptotic free states ⓘ |
| codomain | Hilbert space of asymptotic states ⓘ |
| computedUsing |
Dyson series
ⓘ
perturbation theory ⓘ time-ordered exponentials ⓘ |
| constraint |
analyticity in complex energy and momentum variables
ⓘ
cluster decomposition principle ⓘ crossing symmetry (in many relativistic theories) ⓘ |
| dependsOn | interaction Hamiltonian ⓘ |
| domain | Hilbert space of asymptotic states ⓘ |
| elementType | complex numbers ⓘ |
| encodes |
probabilities for scattering processes
ⓘ
transition amplitudes ⓘ |
| field |
quantum field theory
ⓘ
scattering theory ⓘ |
| formalDefinition | S = 1 + iT ⓘ |
| hasElement |
decay amplitudes
ⓘ
elastic scattering amplitudes ⓘ inelastic scattering amplitudes ⓘ particle production amplitudes ⓘ |
| historicalContext | central object in the S-matrix program of the 1950s–1960s ⓘ |
| maps | in-states to out-states ⓘ |
| mathematicalNature | infinite-dimensional matrix in general ⓘ |
| matrixElementNotation | S_{fi} = ⟨f|S|i⟩ ⓘ |
| probabilityRelation | P_{i→f} = |S_{fi}|^2 ⓘ |
| property |
Lorentz invariant (in relativistic QFT)
ⓘ
causal (consistent with microcausality) ⓘ unitary (S†S = 1) ⓘ |
| relatedConcept |
Feynman diagrams
ⓘ
LSZ reduction formula ⓘ T-matrix ⓘ cross section ⓘ optical theorem ⓘ scattering amplitude ⓘ unitarity ⓘ |
| relates | initial states to final states ⓘ |
| representation |
in momentum space
ⓘ
in partial waves ⓘ |
| symmetryConstraint |
Poincaré invariance
ⓘ
internal symmetries of the theory ⓘ |
| usedFor |
computing decay rates
ⓘ
predicting experimental scattering cross sections ⓘ testing quantum field theories against experiment ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: S-matrix Description of subject: The S-matrix (scattering matrix) is a fundamental construct in quantum field theory that encodes the probabilities for transitions between initial and final particle states in scattering processes.
Referenced by (11)
Full triples — surface form annotated when it differs from this entity's canonical label.
Dyson’s proof of equivalence of Feynman and Schwinger–Tomonaga formulations of QED
→
relatedWork
→
S-matrix
ⓘ
this entity surface form:
Dyson’s papers on the S-matrix in quantum electrodynamics
this entity surface form:
S-matrix theory
this entity surface form:
T-matrix