2 Geometric Setup

We work in closed FRW minisuperspace with cosmological constant Λ = 1  and a scalar field ϕ  , Wick-rotated to Euclidean time τ ∈ [0,τmax]  . The Euclidean action is:

     ∫  τmax[       ˙a2   1   2  1  3 2   Λ 3]
SE =        − a + κ-a-+ 2a ˙ϕ + 2-a ϕ +  3a   dτ +  2a(τmax),
       0

with κ = 0.15  . The classical Hartle-Hawking no-boundary instanton satisfies a(0) = 0  and a˙(τmax) = 0  , and is given by:

 ∗      1-              ∘ ----          π--
a (τ) = ω sin (ω τ),  ω =   Λ∕3,   τmax =  2ω,

with ϕ(τ) = 0  as the classical scalar background.

We generate large ensembles of random histories that respect these boundary conditions and compute both the Euclidean action S
 E  and the spectral complexity C
  s  of each history.