Paper 07Canonical2026-07-15

Bulk-to-Brane Projection, Dynamical Nonclosure, and Observable Residues in Randall–Sundrum Gravity

The physical witness: a concrete model-relative projection and nonclosure result in RS2, with its exact discrimination boundary

DOI: 10.5281/zenodo.21371861 View on Zenodo

Authority role

The physical-witness layer: constructs gauge-inequivalent RS2 bulk states with identical brane readout and different brane futures, derives the exact projected Einstein equation, extracts a parameter-free cross-regime prediction, and proves the operational-equivalence boundary that caps its own interpretation.

Summary

Working inside the positive-tension Randall–Sundrum (RS2) braneworld — an additional physical postulate, not derived — this paper delivers the framework's concrete physical witness: an explicit pair of five-dimensional gravitational states identical to a brane observer now that evolve to differ later, so the instantaneous brane state admits no deterministic evolution law over the full source domain. It derives the exact projected Einstein equation line by line, obtains the positive high-density rho-squared term and bulk-state dark-radiation term, and eliminates the common AdS radius to yield a parameter-free cross-regime relation linking cosmology to weak-field gravity. Crucially it proves its own limit: every brane-only experiment is reproduced exactly by a four-dimensional pushforward theory, so the result is a model-relative projection and nonclosure theorem, not a proof that our universe is five-dimensional.

Notes

Reading notes

The physical-witness layer of the sequence. The stage is the positive-tension, two-sided, $Z_2$ -symmetric Randall–Sundrum model (RS2): five-dimensional Einstein gravity with a negative bulk cosmological constant and matter confined to a brane. Selecting RS2 is an additional physical postulate — nothing in the paper derives it.

Theorem — Same readout, different future (the witness)

There exist two gauge-inequivalent bulk configurations — the unperturbed brane and one carrying a smooth, finite-energy transverse-traceless bulk wave packet initially supported away from the brane — with identical instantaneous brane readout whose brane readouts differ at a later time. Existence is proved by explicit Kaluza–Klein spectral construction. Hence no deterministic evolution law on the instantaneous brane Cauchy state reproduces every source trajectory over the full RS2 source domain.

The tensorial counterpart is derived line by line: the Israel junction condition and Gauss–Codazzi identity give the exact projected Einstein equation with response tensor $\mathcal{C}^{\mathrm{RS}}_{\mu\nu} = \kappa_5^4 \Pi_{\mu\nu} - E_{\mu\nu}$ , where the Bianchi identity fixes only the divergence of the Weyl term — its transverse-traceless content, the free bulk response, is undetermined by brane data. Evaluated exactly in the Friedmann sector this yields a positive $\rho^2$ correction and a dark-radiation term $\mu/a^4$ whose magnitude is a bulk-state parameter, not brane matter. In the weak-field sector the bulk is eliminated exactly at linear tree level, and the long-distance potentials follow for $r \gg \ell$ .

Cross-regime relation

A_\Psi = \tfrac{1}{2}A_\Phi, \qquad B = \tfrac{\kappa_4^4}{24}A_\Phi = \tfrac{\kappa_4^4}{12}A_\Psi

Eliminating the common AdS radius between the cosmological and weak-field regimes leaves no free brane parameter. Violation falsifies minimal RS2; agreement at a nonzero value favors it without falsifying an independently parameterized 4D theory.

The paper then proves its own interpretive ceiling. A pushforward lemma shows that for every brane-only protocol — including adaptive ones — the induced Tier-1 history law reproduces the RS2 record distribution exactly, and in RS2 this is realized concretely: the four-dimensional gravity-plus-CFT description reproduces the same $1/r^3$ residue. The result is therefore positive at the level of model-relative projection and nonclosure, and negative at the level of unrestricted ontological discrimination.

Cite this paper

Rodgers, Jeremy. (2026). Bulk-to-Brane Projection, Dynamical Nonclosure, and Observable Residues in Randall–Sundrum Gravity. https://doi.org/10.5281/zenodo.21371861