Temporal statistics can alter a return-probability diagnostic without changing the number of spatial coordinates. Random-clock examples expose the finiteness and regulator conditions needed to interpret a claimed dimensional flow.
01What a temporal explanation of dimensional flow would mean
A dimension can count independent coordinates, describe the growth of volume, or characterize how a diffusion probe returns to its starting point. A temporal model can alter the third quantity without changing the first. This distinction is central when reading the fractal-time proposal and its newer renewal-clock formulation.
The SMM/DTT connection is that observed elapsed time need not parameterize microscopic updates uniformly. If the clock relating source activity to completed records is irregular, a probe described against observed time can display anomalous scaling even on a fixed spatial graph.
02Two clocks in a statistical construction
Let u count operational progress and t be the time assigned to observation. A random nondecreasing process E(t) can connect them. If Y(u) is an ordinary diffusion, X(t)=Y(E(t)) is the same underlying spatial motion sampled through the random clock.
The probability density of X is an average of the operational kernel over the distribution of E(t). This averaging is called subordination in the broad clock-change sense; inverse-subordinator constructions must be distinguished from direct subordinators because their equations and scaling properties differ. The distribution and independence assumptions are part of the model.
P(x,t) = ∫₀∞ K(x,u) f(u,t) du.
Figure 1. A random operational clock changes observed diffusion. The illustration subordinates diffusion in operational time u to an intermittent clock u(T). Flat portions represent waiting periods. The resulting memory does not imply two independently readable laboratory clocks. View full size ↗
03How a power-law return diagnostic is computed
Suppose an admissible return observable obeys P₀(t)=C t^(-q) over a specified interval. Its scale-local spectral dimension is d_s(t)=-2 d logP₀/d logt=2q there. This is a calculation on a chosen diagnostic, not a count of coordinates.
For ordinary Euclidean diffusion in d dimensions, the return density has exponent d/2. Replacing operational time by a deterministic u=t^D would formally give exponent Dd/2. Random clocks cannot always be substituted this way: averaging a singular kernel over a distribution is a separate operation with its own convergence requirements.
d_s(t) = -2 d log P₀(t) / d log t.
04The finiteness condition matters
For an inverse-stable clock, small operational times can contribute strongly to the average of u^(-d/2). In dimensions at least two, the coincident continuum heat kernel may diverge under the relevant small-u behavior. A formal scaling argument that silently assumes a finite value at the origin can therefore fail.
A finite spatial regulator, a smeared return observable, or a carefully identified asymptotic regime can produce meaningful diagnostics. One should state which is used and analyze its cutoff dependence. The appropriate result is then about that well-defined observable; it need not be the unqualified identity d_s=Dd for every inverse-stable process.
Figure 2. Spectral dimension is a return-probability slope. For the specified toy return law P(σ) = C σ⁻ᵈˢ/², the log–log slope is −ds/2. The two straight lines are ideal examples with ds = 2 and ds = 4; they are not observations of a dimensional flow. View full size ↗
05What can be learned from a finite graph
On a finite graph, the operational return probability is bounded and the clock average is well-defined under a normalized waiting-time law. At sufficiently long times it approaches a stationary value, so the local spectral dimension tends toward zero rather than remaining at an intermediate power-law value forever.
A useful numerical study therefore plots several scales and graph sizes. An intermediate slope can support a scaling regime, but early-time resolution effects and late-time finite-size saturation must be identified. This is a more informative experiment than selecting one fitted exponent from one small graph.
06The conceptual gain for DTT
The model makes a precise point: temporal statistics can change what an observer infers from a propagation or diffusion experiment. It does not by itself generate three-dimensional space, establish quantum gravity, or identify the random clock with the unique Single Monad dynamics. Those require additional structure.
The research opportunity is to derive the waiting-time law and its regime from a specified source, then compare several diagnostics fixed by that same law. Return probabilities, relaxation kernels, and clock fluctuations could become related outputs. Their agreement would be more constraining than a chosen dimensional-flow curve alone.
KEEP THE CONNECTION
Key ideas
Spectral dimension is a probe-dependent scaling diagnostic.
A random clock requires an average, not a simple substitution of time variables.
Finite return probabilities and regulator control are essential.
Scope of the argument. The elementary return-law calculation is exact when its observable exists; universal dimensional-flow claims require further hypotheses.
The selected latency and scaling laws define a model. Their consequences should be assessed separately from derivation of those laws, physical clock calibration and empirical agreement. A running spectral diagnostic does not by itself reconstruct metric distance or prove that physical space changes dimension.