Gravity Is Not Weak; the Vacuum Is StiffLayer E (Cosmology) of the R^8 Framework: Gravity-First Annealing Inflation and GR-Safe Local Screening in a Bank-Leaf EFT AbstractWe present the Layer E (cosmology) extension of the R^8 framework as an effective-field-theory (EFT) existence proof for a gravity-first early universe. The central axiom is that gravity is not a weak interaction; it is the low-energy response of an exceptionally stiff vacuum. In this picture the vacuum is endowed with an internal discrete Bank structure (an internal lattice or fiber), whose formation precedes the appearance of particle degrees of freedom and provides (i) an induced Einstein-Hilbert sector at long wavelengths and (ii) a finite, exhaustible non-equilibrium energy reservoir that can drive an inflationary stage. The discrete Bank implies a modulated ‘washboard’ potential (schematically Z48), rendering cold slow-roll inflation generically untenable. We therefore adopt a strong-dissipation warm/annealing regime in which the field does not need to roll on a flat potential but instead advances by thermally assisted hopping/tunneling between successive minima (warm chain inflation). The inflationary phase ends when the lattice relaxation completes, naturally realizing exhaustible inflation without invoking an eternally metastable plateau. Two structural consequences are addressed quantitatively. First, discrete stepping generically imprints oscillatory features (‘ringing’) in the scalar spectrum; we introduce a slalom condition requiring many Bank steps per Hubble time (ν_steps ≫ 1) so that features are averaged below observational sensitivity. Second, discrete symmetry breaking generates internal domain boundaries; we treat their fate as a constitutive boundary law of the Bank→Leaf interface (IRIS confinement channel) together with a Z48→Z24 projection that yields ‘phantom’ walls with no Standard-Model vacuum contrast. Residual leakage into the 4D EFT is parameterized by a small leak_dw ≪ 1 and shown to remain subdominant in representative toy calibrations. We provide a compact set of consistency checks. The toy annealing system is calibrated to produce N_end ≃ 60 e-folds with a smooth energy handoff to radiation (ρ_R/ρ_L ≃ 1 at the end) and ε_H → 1 at exit. Under the ringing constraint we find min ν_steps(last 60 e-folds) ≃ 50 and A_ring ≲ O(10^−2). A warm-spectrum proxy evaluated 55 e-folds before the end yields n_s ≃ 0.966 and r ≃ 0.03 with a strong dissipation ratio Q ≃ 18 and T/H ≃ 0.6 (toy units), highlighting where microphysical warm-growth corrections must be controlled. In the infrared, we enforce GR safety by requiring any additional Bank-coupled scalar response to have either a sufficiently small visible coupling (α ≲ 3.4×10^−3 if massless) or a mass gap. Using the standard Yukawa-suppressed PPN estimate γ(r) = (1 − α^2 exp(−m r)) / (1 + α^2 exp(−m r)), Cassini-scale bounds imply m ≳ 2×10^−15 eV for α ≈ 1. We also demonstrate that piecewise ‘inside/outside’ mass gaps can confine modifications to laboratory scales while leaving Solar-System tests (e.g., Mercury perihelion) indistinguishable from GR. Description This release provides the cosmology extension (‘Layer E’) of the R^8 framework. The goal is not to replace General Relativity (GR) in its validated domain, but to supply a structured origin story for why GR is the correct long-wavelength description while keeping the vacuum microscopic and discrete.A guiding principle is what we call structural honesty. Occam’s razor has two edges: one edge shaves entities, the other shaves hidden inconsistencies. Layer E pays a bookkeeping cost (explicit structure) to avoid placing the cost in the fine print (a perfectly smooth, finely tuned inflationary potential).The entire cosmology module is organized as a rigidity cascade. A single premise, the existence of a stiff internal Bank lattice, forces a sequence of ‘action–reaction’ steps:Rigidity ⇒ induced gravity: integrating out Bank microstructure yields an emergent Einstein-Hilbert sector at long wavelengths, with the effective Planck scale interpreted as vacuum stiffness.Rigidity ⇒ washboard potential: discrete Bank structure implies a modulated landscape (Z48) for the relevant collective degree(s) of freedom.Washboard ⇒ warm/annealing inflation: cold slow-roll fails; inflation must be sustained by strong dissipation (Q ≫ 1) and a chain-like advance across minima.Discrete steps ⇒ ringing: stepping would imprint oscillatory features in the scalar spectrum unless the field traverses many minima per Hubble time.Discrete vacua ⇒ internal walls: domain boundaries are unavoidable; their survival in 4D is controlled by the Bank→Leaf constitutive boundary law (IRIS confinement channel) and by Z48→Z24 projection (‘phantomness’).Late-time constraints ⇒ screening/locality: any residual Bank-coupled force must be short-ranged or weakly coupled in the visible sector to preserve GR in the Solar System. Key EFT Relations (as used in the toy models)Warm/annealing equation of motion (schematic): ϕ¨ + 3H(1+Q) ϕ˙ + V′(ϕ) = 0, with Q ≡ Γ/(3H) in the strong dissipation regime.Slalom condition (ringing suppression proxy): ν_steps ≡ (steps per Hubble time) ≫ 1, implemented as a lower bound on ν_steps over the last ≈ 60 e-folds.Domain wall bookkeeping: leak_dw ≪ 1 parameterizes residual Bank→Leaf leakage of internal wall energy into the 4D EFT; cosmological viability requires max(ρ_DW/ρ_tot) ≪ 1.PPN γ with Yukawa suppression (scalar-tensor proxy): γ(r) = (1 − α^2 exp(−m r))/(1 + α^2 exp(−m r)) ≃ 1 − 2 α^2 exp(−m r) for α^2 exp(−m r) ≪ 1. Toy Model HighlightsE-fold calibration: N_end ≈ 60 (typical runs: N_end ≃ 60.49) with ε_H(end) ≈ 1 and a smooth energy handoff ρ_R/ρ_L(end) ≈ 1.Ringing control: after enforcing the slalom bound, min ν_steps(last 60) ≈ 50 and A_ring is reduced to the O(10^−2) level in the proxy diagnostics.Warm-spectrum proxy at pivot (N_* = N_end − 55): n_s ≈ 0.966, r ≈ 0.03 with Q_* ≈ 18 and T/H_* ≈ 0.6 (toy units). These numbers are presented as an internal consistency check; microphysical warm corrections are flagged as an explicit follow-up.Domain-wall confinement (IRIS): with representative leakage settings, max(ρ_DW/ρ_tot) is kept extremely small (toy examples at or below the 10^−8 level), preventing wall domination.Solar-System safety: Cassini-scale bounds require either α ≲ 3.4×10^−3 for a massless scalar or a mass gap m ≳ 2×10^−15 eV for α ≈ 1. This can be strengthened by adopting the Cassini impact-parameter scale. A piecewise ‘inside/outside’ mass-gap choice can confine any visible deviation to laboratory distances while leaving Mercury perihelion advance indistinguishable from GR. Scope and Non-ClaimsThis is an EFT-level proposal accompanied by toy models designed to stress-test consistency: successful calibration, ringing suppression, domain-wall non-domination, and Solar-System GR safety.The work does not claim a completed microphysical derivation of Γ(ϕ,T), nor a precision computation of the scalar power spectrum. It identifies the structural requirements that any such microphysics must satisfy.The framework explicitly avoids long-range repulsive ‘antigravity’. Local weakening/screening is treated as a control-and-stability problem under positive-definiteness and observational bounds. Keywordsemergent gravity; vacuum rigidity; warm inflation; chain inflation; dissipative dynamics; oscillatory features; CMB ringing; domain walls; confinement boundary law; screening; PPN constraints; Cassini; effective field theory; Crystalline Axiverse.