Lagrangian space consistency relation for large scale structure
  Consistency relations, which relate the squeezed limit of an (N+1)-point
correlation function to an N-point function, are non-perturbative symmetry
statements that hold even if the associated high momentum modes are deep in the
nonlinear regime and astrophysically complex. Recently, Kehagias & Riotto and
Peloso & Pietroni discovered a consistency relation applicable to large scale
structure. We show that this can be recast into a simple physical statement in
Lagrangian space: that the squeezed correlation function (suitably normalized)
vanishes. This holds regardless of whether the correlation observables are at
the same time or not, and regardless of whether multiple-streaming is present.
The simplicity of this statement suggests that an analytic understanding of
large scale structure in the nonlinear regime may be particularly promising in
Lagrangian space.
