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=== Effective field theory ===
The fermions of STS represent the differentials of the wavefunctions understood as differential forms.<ref name=":6"/> These differentials and/or fermions are intrinsically linked to stochastic Lyapunov exponents<ref name=":Graham"/> that define the [[butterfly effect]] so that the [[Effective_field_theory|effective field theory]] for these fermions -- referred to as [[Goldstino|goldstinos]] in the context of the spontaneous TS breaking -- is a theory of the butterfly effect.
{{Equation box 1
|indent=:
|title='''generating functional'''
|equation=<math>
G(\eta) = - \lim_{T\to\infty} log \langle g | \hat M_{T/2, -T/2}(\eta)| g \rangle / \langle g | \hat M_{T/2, -T/2}(0)| g \rangle,
</math>
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where <math> \eta </math> are external probing fields coupled to the system and <math>g</math> is the ground state, i.e., an eigenstate of the GTO picked up from the set of eigenstates with the lowest real part of their eigenvalues, a requirement needed to ensure stability of the response. The ground state represents the system which has been allowed to evolve for a long time without perturbations. The generating functional describes how the ground state responses to external perturbations.
When TS is spontaneously broken, the ground state is degenerate. In higher-dimensional theories, this degeneracy evolves into a gapless branch of excitations called goldstinos. Due to gaplessness of goldstinos, the resulting effective field theory must be scale-invariant, or, a conformal field theory
<ref>{{cite book
| last = Brauner
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| access-date = 2025-06-05
}}</ref>
| last1 = Di Francesco
| first1 = Philippe
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