Type Ia supernovae and BAO measurements show the cosmic expansion is asymptotically approaching an exponential growth rate consistent with a de Sitter phase. The standard model accommodates this by assuming a constant vacuum energy density Λ that becomes dominant as matter dilutes (Riess 1998; Perlmutter 1999). The why-now coincidence question persists: why did the exponential trend begin at this specific epoch rather than earlier or later?
The standard model treats Λ as a fixed constant and matter density as evolving independently. The transition to Λ domination then has to occur at one specific epoch (now), and the model offers no dynamical reason for that timing. The exponential trend exists in ΛCDM, but as an unmotivated boundary condition rather than a derived consequence.
SCT replaces the hot-dense-center with a superluminal collision and the thermalized debris field that became our visible universe. From this single change, the late-time exponential trend has a concrete dynamical origin. Mesh dissipation operates simultaneously at every level of the gravitational hierarchy above our pocket (P14). As each level's mesh weakens, it reduces its stabilizing contribution to all child frames, accelerating dissipation at lower levels — a cascade producing exponential growth in the total dissipation rate (P18).
The e-folding timescale is set by the largest parent frames, whose decay timescales greatly exceed the current Hubble time (roughly 10¹¹ to 10¹³ years for galactic-cluster scales). The exponential is currently in its very early phase, which is consistent with the observed dark-energy equation-of-state parameter w ≈ −1 today (P17). The de Sitter-like trend is the expected long-term behavior of a hierarchy where every parent frame is slowly weakening at the same time, with the weakening accelerating exponentially through the multiplicative compounding of nested levels.
The same mechanism resolves the Hubble tension, the S₈ deficit, the cosmological-constant fine-tuning problem (recid 3), and the coincidence problem (recid 9). The why-now question dissolves because the exponential is not centered on a special epoch; it is centered on the asymptotic future, and we happen to be observing in its early phase. There is no need for quintessence, modified gravity, or anthropic selection. The de Sitter trend is what mesh-dissipation cascade looks like in its early-phase regime.
If precision DESI Year 5 plus Euclid combined dark-energy constraints find w(z) constant at w = −1.000 ± 0.005 across all redshifts (no temporal evolution of the equation of state), the long-term exponential cascade prediction is refuted. The signature M5 prediction is gentle drift in w(z) with environment-dependent amplitude that grows toward the future as the cascade compounds.