Dark Matter as Gravitational Memory: A Causal Rail for Wave Function Collapse — A Testable Hypothesis

What if dark matter is not a missing particle, but the gravitational memory of the Universe's past quantum collapses — and that memory helps shape what collapses next?

In a companion paper, we showed that dark matter abundance emerges from the thermodynamic cost of irreversible decoherence, with zero fitted parameters. But that framework treated the archive as passive.

This paper asks: what if it isn't?

We propose that the accumulated record of past wave function collapses acts as a causal rail — progressively narrowing the corridor within which future collapses can unfold. The past does not determine the future. But it constrains it.

This single idea, minimally formalized, leaves the dark matter abundance intact while introducing a new class of prediction: structure growth explicitly tied to the Universe's archival history — something the standard model has no natural mechanism to generate.

The framework produces three falsifiable signatures for DESI DR2/DR3 and Euclid Year 1, and a precise condition under which it is ruled out entirely.

In this framework, dark matter is not merely an invisible substance. It is the gravitational memory of cosmic history — and a possible active participant in what comes next.

Keywords: Dark Matter; Information-Theoretic Cosmology; Wave Function Collapse; Quantum Decoherence; Landauer Principle; Structure Growth; Assembly Bias; DESI; Euclid.