Work in progress · 2026

Discrete Emergent Gravity

Spacetime, gravity, and the Standard Model's structure from a single postulate.

1
Postulate
3
Calibrated inputs
6
Key results
17
Falsifiable predictions
Matteo Pinna · Independent researcher, Madrid · ORCID 0009-0004-4078-9015 · Get in touch
Full research programme All derivations, results, and open problems in one document doi.org/10.5281/zenodo.21724820

The single postulate

\[H = \sum_n \left[\frac{p_n^2}{2m} - \frac{\alpha_{\exp}}{2}\,a_n^2\right] = 0\]
The atomsSpacetime consists of \(N\) discrete Planck-scale constituents, each characterised by a size parameter \(a_n\) and carrying \(g = 442\) internal quantum states.
The number \(g = 442\)Follows from the requirement that the gauge algebra SU(21)×U(1) embeds the Standard Model, given the adjoint-plus-doublet representation choice for each atom's internal states. The adjoint of SU(21) contributes 440 states; U(1) contributes 2. The representation choice and the selection of SU(21) carry honest caveats detailed in the manuscript.
What followsThe SM gauge group, the dark energy equation of state \(w=-1\), black hole unitarity, and the Higgs boson mass are derived consequences of this constraint. The cosmological constant's magnitude, two Higgs-sector EWSB parameters, and the generation count each require a calibrated input or remain open derivation problems — stated plainly throughout.

Results

Key results — derived from the single postulate

Result Value Status Note
Higgs boson mass \(m_H\) \(124.8\pm2.4\ \text{GeV}\) 0.19σ from PDG Two EWSB inputs disclosed
Dark energy \(w\) \(w = -1\) exactly Exact geometric corollary Downstream of calibrated \(\Lambda\)
Area quantum \(\Delta A\) \(4\ln(442)\,\ell_P^2 \approx 24.37\,\ell_P^2\) Derived From \(g = 442\) alone
Barbero–Immirzi analogue \(\gamma_{\rm DEG}\) \(\approx 2.24\) Derived Not fitted — group-theoretic output
Page curve \(S_{\rm rad}(k)\) \(\min(k,\,N{-}k)\ln 442\) Exact (leading order) Kinematic from finite-dim \(\mathcal{H}\)
WdW unitarity Exact Exact Kinematic from finite-dim \(\mathcal{H}\)

The cosmological constant \(\Lambda\) is a calibrated input (fit to \(\Lambda_{\rm obs}\)); \(w = -1\) is the derived consequence downstream of it.

Framework results — derived, load-bearing

Gravity

  • Newton's law with exact coefficient [semi-derived; requires \(g_{\rm eff}=1\)]
  • Einstein field equations emergent [semi-derived]
  • Equivalence principle from overlap
  • Entropy–time relation \(dS/d\tau = 9k_B N\) — exact algebraic consequence of definitions
  • PPN parameters: Cassini bound satisfied generically by Vainshtein screening [no specific value derived]
  • Emergent Lorentz invariance \(\eta_2 \sim (\ell_P/a)^2\) — structurally suppressed
  • \(w = -1\) exact geometric corollary
  • UV cutoff at \(a\) — value currently undetermined [open problem]

Particle physics

  • SM gauge group from SU(21) [derived]
  • Family symmetry SU(3)fam identified — generation-count reduction 5→3 [open problem]
  • All SM quantum numbers verified
  • No light exotic particles
  • FN parameter \(\varepsilon = e^{-3/2} \approx 0.223\) [approximate]
  • CKM phase \(\delta_{\rm CKM} = 1.20\ \text{rad}\) (0.3% match) [input]
  • Strong CP: \(|\bar{\theta}_{\rm tree}| = 0\) — Nelson–Barr mechanism [conditional]
  • EW oblique \(S, T, U\) satisfied
  • Top Yukawa \(y_t\sim1\) predicted
  • Hierarchy \(\Delta_{\min} = 7.3\pm0.5\) — no SUSY required [approximate]
  • Doublet-triplet splitting algebraic
  • \(M_{\rm GUT}\sim9\times10^{14}\ \text{GeV}\) [provisional]

Cosmology

  • Flatness \(\Omega=1\) from discrete Hartle–Hawking — no tuning [derived]
  • CMB primordial spectrum: fossil of pre-geometric phase
  • \(w = 1/3\) at quantum-classical transition [asserted; physical basis not yet derived]
  • No inflaton, no gravitino / moduli problem
  • All Sakharov conditions structurally present from SU(21)
  • \(\eta_B\sim6\times10^{-10}\) — reproduced by construction of \(\varphi_{\rm DEG}\) [not independent]
  • MOND \(a_0^{\rm DEG} = 8.6\times10^{-11}\ \text{m/s}^2\) — 28% below observed; semi-derived
  • Tully–Fisher \(M\propto v^4\) [derived]
  • \(\nu_{R_1}\) dark matter at 7–10 keV [mass derivation open]

Quantum gravity

  • Black hole information paradox resolved — finite-dim \(\mathcal{H}\) forces unitarity [exact]
  • Scrambling \(\tau_{\rm sc}\sim\mathcal{O}(\tau_{\rm Horizon})\)
  • WdW unitarity exact
  • Born rule: classical counting from internal \(\mathcal{H}\) [semi-derived; not a resolution of the quantum measurement postulate]
  • Decoherence \(\tau_{\rm dec}\sim2.3\times10^{-37}\ \text{s}\) [estimated]
  • Singularity resolution: \(a_n = 0\) requires \(\tau \to -\infty\) [approximate theorem]
  • \(\Delta A = 4\ln(442)\,\ell_P^2\) area quantum [conditional: \(j=j_{\rm min}\) dominance; BH coefficient imported]

Falsifiable predictions

Observable Prediction Experiment Timeline Falsifier
Already confirmed
GW speed \(c_{\rm GW}\) \(= c\) exactly GW170817 ✓ confirmed
Ongoing
No WIMP signal Zero direct detection LZ / XENONnT ongoing WIMP detection
CPT-odd LV \(\eta_1\) \(= 0\) [approximate] Fermi-LAT / CTA ongoing Any CPT-odd MDR detection
MOND acceleration \(a_0^{\rm DEG}\) \(8.6\times10^{-11}\ \text{m/s}^2\) SPARC / Vera Rubin ongoing 28% below observed — open item
2–5 years
Dark energy \(w\) \(= -1\) exactly DESI / Euclid 2–5 yr Any \(5\sigma\) \(w\neq-1\) detection
Power spectrum \(P(k)\) Two-scale suppression \(k\sim0.4\) and \(90\,h/\text{Mpc}\) DESI / Euclid 2–5 yr Suppression at neither scale
3–10 years
Normal neutrino ordering \(m_{\nu_1}\sim10^{-5}\ \text{eV}\) JUNO 3–5 yr Inverted ordering confirmed
Higgs coupling \(\kappa_V\) [open tension] \(0.432\) tree; ceiling \(0.797\) analytical HL-LHC ~5 yr \(\kappa_V\) consistent with SM at \(2\sigma\)
Neutron EDM \(d_n\) \(2\times10^{-53}\text{–}6\times10^{-40}\ e{\cdot}\text{cm}\) n2EDM@PSI ~2026 Signal \(>10^{-26}\ e{\cdot}\text{cm}\)
Proton decay \(\tau_p\) [provisional] \(\sim10^{33\text{–}34}\ \text{yr}\) Hyper-Kamiokande 5–10 yr \(\tau_p > 10^{35}\ \text{yr}\)
2030s–2037
Tensor-to-scalar ratio \(r\) \(0.00452\pm0.002\) [semi-derived] CMB-S4 / LiteBIRD ~2032 \(r > 0.01\)
Non-Gaussianity \(f_{\rm NL}\) \(^\dagger\) \(\approx0.0076\) (null) [asserted] CMB-S4 ~2032 \(f_{\rm NL} > 1\) at \(2\sigma\)
Env. Tully–Fisher variation \(\lesssim10\%\) [conditional] Vera Rubin / LSST ~2030–35 Zero variation at \(5\sigma\)
Di-Higgs cross-section \(\sigma_{HH}\) \(57.5\pm10\ \text{fb}\ (1.85\times\text{SM})\) HL-LHC ~2035 \(\sigma < 40\ \text{fb}\) at \(5\sigma\)
Dark matter X-ray line \(3.5\text{–}5\ \text{keV}\ (\nu_{R_1},\ m_s\sim7\text{–}10\ \text{keV})\) ATHENA ~2035 Non-detection in viable window
LISA breathing mode \(^\dagger\) Undetectable if \(a \gtrsim\) pm-scale [conditional on unconfirmed \(a\)] LISA ~2037 Polarisation above \(10^{-3}\)
EMRI phase shift \(^\dagger\) \(\Delta\Phi\sim10^{-82}\ \text{rad (null)}\) LISA ~2037 Phase anomaly at LISA sensitivity
Long-term
CMB \(\mu\)-distortion \(\mu\sim10^{-5}\) PIXIE / Voyage 2050 15–20 yr \(\mu < 10^{-6}\)
Di-Higgs at 100 TeV \(2267\pm400\ \text{fb}\) FCC-hh ~2040+

\(^\dagger\) Null prediction: DEG predicts signal below experimental threshold. Detection above threshold would falsify.

Open problems

Known tension

Higgs coupling \(\kappa_V = 0.432\)

Currently \(14.2\sigma\) from the LHC measurement at tree level. Non-perturbative DGMLY enhancement raises the analytical ceiling to \(\kappa_V = 0.797\) (\(5.1\sigma\)); no analytical method reaches \(\kappa_V > 0.920\). Resolution requires DEG-L Group C lattice computation. The programme's single most important open conflict with data.

Genuine open derivation

Cosmological constant \(\alpha_{\rm exp}^{\rm cosm}\)

\(\alpha_{\rm exp}^{\rm cosm}\) is a disclosed input, calibrated directly to match \(\Lambda_{\rm obs}\). Several candidate derivation mechanisms have been tested and ruled out — including identification with a running SU(21) gauge coupling, a dynamically-generated confinement scale, and a unimodular-gravity integration constant. Closing this gap requires a theoretical breakthrough, not a numerical refinement.

High-priority open problem

Atomic lattice spacing \(a\)

No derivation of \(a\) currently exists. The RG route gives the wrong sign. The only numerical bound is a weak lower threshold from LISA sensitivity (a few picometers). This quantity is load-bearing across the cosmological-constant discussion, the LISA null prediction, and the matter power-spectrum features.

Open reduction problem

Five-to-three generation reduction

The embedding chain's own branching rule gives five copies of the family-triplet under \(\mathrm{SU}(3)_{\rm fam}\), not three. Identifying exactly three as the observed SM generations — and accounting for the other two — is not currently derived. Three generations are assumed as a working hypothesis throughout the fermion sector.

Not yet derived

Galaxy cluster profiles at large \(r\)

The MOND mechanism provides partial screening only. Quantitative cluster mass profiles at large radii are not yet derived. The \(\sigma_8\) growth-factor calculation does not currently reproduce its own stated product, and no first-principles derivation is available.

Outside current framework

Spectral index \(n_s\)

The DEG quantum epoch gives \(n_s = 4\) [asserted; the argument is \(k\)-independent and cannot by itself produce a spectral index]. The observed \(n_s \approx 0.963\) is identified as a fossil of the pre-geometric phase \(\tilde{G} \supset \mathrm{SU}(21)\times\mathrm{U}(1)\). Seven internal mechanisms exhausted; an eighth (Euclidean Bessel) remains under active investigation.

Disclosed inputs

Higgs EWSB parameters \(\varepsilon_\alpha, \varepsilon_\beta\)

The two electroweak-symmetry-breaking parameters feeding the Higgs mass prediction are currently calibrated inputs, not independently derived. Three independent checks confirm the stated Coleman–Weinberg potential does not reproduce them. Deriving these from first principles is an open research target structurally analogous to \(\alpha_{\rm exp}^{\rm cosm}\).

Unattempted research direction

Sterile neutrino mass \(\nu_{R1}\)

The naive type-I seesaw formula for \(M_{R1}\) misses the 7–10 keV target by roughly thirteen orders of magnitude. Separately, standard leptogenesis falls short of the \(L_{\rm active}\sim10^{-3}\) needed for resonant sterile-neutrino production by five orders of magnitude. A candidate Affleck–Dine mechanism [conditional] closes most of this gap, to within a factor of ~6 — but the coefficient closing that remainder is fit to the target rather than derived. Both gaps point to the same unaddressed sector: a dedicated suppression and transfer mechanism motivated by the atom-overlap geometry used in the fermion sector, which has not yet been attempted.

Imported assumption

Bekenstein–Hawking coefficient from \(g_{\rm eff}=1\)

Substituting \(g_{\rm eff}=1\) and Planck-sized screen atoms into the DEG entropy formula gives zero entropy per screen atom, not the coefficient \(1/4\). The \(S_{\rm screen}=\kB A/(4\ell_P^2)\) result is currently imported from standard semiclassical gravity rather than shown to follow from \(g = 442\). This also affects the independence of the area-quantum derivation.

Resolution path identified

DEG-L lattice programme

Four ensemble specifications (E1–E4) are complete. Three observable groups: topology (\(K_{\rm fam}\)), Higgs floor, V−A spectral function (\(\kappa_V\)). Estimated ~\(10^5\) GPU-hours. Results would sharpen the Higgs mass uncertainty and constrain the \(\kappa_V\) resolution pathway.

Framework & context

DEG posits that spacetime is a statistical aggregate of \(N\) discrete Planck-scale atoms, each characterised by a size parameter \(a_n\) and an internal Hilbert space of dimension \(g = 442\). The dynamics is governed by a single Hamiltonian constraint — no background metric, no continuous fields at the fundamental level.

From this foundation, the programme derives: the Standard Model gauge group from \(\mathrm{SU}(21)\) group theory alone; dark energy \(w=-1\) exactly; black hole unitarity and the Page curve from the finite-dimensional Hilbert space; the discrete area quantum; and the Higgs boson mass at \(0.19\sigma\) from two disclosed EWSB inputs. The cosmological constant's magnitude is a calibrated input.

What is not claimed. DEG is not a complete theory of quantum gravity. Three calibrated inputs are used — \(\alpha_{\rm exp}^{\rm cosm}\) for the cosmological sector, and \(\varepsilon_\alpha, \varepsilon_\beta\) for the Higgs sector. The generation count from five family-triplet copies to the observed three is an open reduction problem. The atom spacing \(a\) has no derivation. The programme is offered as a coherent, falsifiable research direction with its open problems plainly stated.

Active research directions

  • PriorityDeriving \(\alpha_{\rm exp}^{\rm cosm}\) from first principles — atom cohesion and coarse-grainingopen
  • PriorityDeriving the atomic lattice spacing \(a\) — currently load-bearing across three sectorsopen
  • OpenFive-to-three generation reduction — physical mechanism for the branching-rule surplusopen
  • Open\(\kappa_V\) resolution via DEG-L Group C latticeopen
  • OpenDeriving \(\varepsilon_\alpha, \varepsilon_\beta\) from first principlesopen

This page is updated as the programme develops.

Situating the approach

Like loop quantum gravity and causal set theory, DEG takes discreteness as fundamental. It differs in using a statistical mechanics approach: gravity and time emerge thermodynamically, not through geometric quantisation.

The dark energy equation of state \(w=-1\) follows as an exact geometric corollary of the constraint structure, independent of any input. The cosmological constant's magnitude is a calibrated input.

The Higgs mass prediction \(m_H = 124.8\pm2.4\ \text{GeV}\) agrees with the PDG value at \(0.19\sigma_{\rm theory}\). It is derived from CP-violating observables through a single internal phase \(\varphi_{\rm DEG}\), though two EWSB parameters feeding the calculation are disclosed inputs rather than independent derivations.

The programme is falsifiable at multiple near-term experiments. The most decisive single test is \(w = -1\): any \(5\sigma\) detection of \(w\neq-1\) by DESI or Euclid rules out the entire dark energy sector. DESI DR2 (2025) shows a \(3.1\sigma\) preference for dynamical dark energy in combined analyses — suggestive but below the falsification threshold.

Domain of validity. DEG describes the post-condensation universe — from spacetime atom formation through today. The observed CMB tilt \(n_s \approx 0.963\) is not a DEG prediction; it originates in a pre-geometric phase \(\tilde{G} \supset \mathrm{SU}(21)\times\mathrm{U}(1)\) preceding atom condensation, in the same sense QCD does not derive the electroweak gauge group.

About

Matteo Pinna is a theoretical physicist working independently on quantum gravity and emergent spacetime. His interest in emergent gravity began during his thesis work in 2018, shaped by a conviction that the foundations of physics should admit a simple, parameter-free description — and a specific dissatisfaction with the treatment of time in general relativity.

The starting point was a refusal to accept time as a curved fourth dimension behaving differently from the other three. If space is emergent, time should be too — and the arrow of time, rather than being imposed by initial conditions, should follow from the statistics of whatever is fundamental. DEG is the formalisation of that programme, developed over several years alongside a career in technology.

He is based in Madrid.

Matteo Pinna

Independent researcher

Madrid, Spain

ORCID 0009-0004-4078-9015

LinkedIn

Papers

DOI
DEG Consolidated Manuscript — Complete Research Programme
All derivations, results, open problems, and falsification targets · doi:10.5281/zenodo.21724820
Preprint 2026 Zenodo

The consolidated manuscript is the primary reference for the programme. Not peer-reviewed.

Presentations

2026
Poster · Physicum, University of Tartu, Estonia · 29 June – 3 July 2026
Poster 2026 Zenodo

Poster material will be made available here via Zenodo once uploaded.

Contact

If you work in quantum gravity, emergent spacetime, or related areas and find this programme of interest, I would welcome correspondence — critical feedback especially.

matteo@deg-gravity.com

I am an independent researcher based in Madrid. Collaboration enquiries and comments from researchers with relevant expertise are very welcome.

The papers above contain full derivations, explicit uncertainty budgets, and complete lists of open problems. Nothing is behind a paywall or submission requirement.

The complete research programme — all derivations, results, open problems, and falsification targets — is consolidated in the manifest on Zenodo: doi.org/10.5281/zenodo.21724820

If you are a physicist encountering DEG for the first time and would like to discuss the approach, its foundations, or its limitations, please feel free to write. I am also happy to share derivation notes on specific points not fully developed in the papers.