Pith Number

pith:OUX4EQXW

pith:2026:OUX4EQXWV5DJZPLI6ZJYWLPXHS

not attested not anchored not stored refs resolved

Spatial curvature in Unimodular Gravity

Gilberto Aguilar-P\'erez, Miguel Cruz, Samuel Lepe

Unimodular gravity with spatial curvature and a power-law diffusion term alleviates the Hubble tension to H0 ≈ 73.35 km/s/Mpc while keeping cosmic age at 13.61 Gyr.

arxiv:2605.16751 v1 · 2026-05-16 · gr-qc

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\usepackage{pith}
\pithnumber{OUX4EQXWV5DJZPLI6ZJYWLPXHS}

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Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

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The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Claims

C1strongest claim

the consideration of spatial curvature and diffusion naturally alleviates the Hubble tension, yielding H0 = 73.350_{-0.226}^{+0.221} km/s/Mpc while maintaining a consistent cosmic age of t0 ≃ 13.61 Gyr

C2weakest assumption

We propose a phenomenologically viable power-law Ansatz for the diffusion function, Q(z) = Q0(1+z)^β, which strictly satisfies the second law of thermodynamics by demanding positive entropy production (β Q0 > 0).

C3one line summary

Unimodular gravity with thermodynamically consistent power-law diffusion and spatial curvature is constrained by Pantheon+ and BAO data, producing H0 ≈ 73.35 km/s/Mpc and Ωk0 ≈ -0.109.

References

34 extracted · 34 resolved · 1 Pith anchors

[1] Modified Friedmann Equations with Spatial Curvature In the context of a FLRW universe with spatial curvaturekand a single fluid description, the field equations of UG lead to a modified expansion hist 2023

[2] In Figure 6, we present the dimensionless diffusion functionQ(z)/H2 0 reconstructed 20 via GPs for a closed universe using our best-fit curvature parameter (Ωk0 =−0.109)

[3] The cosmological constant problem, 1989

[4] Diffusion in unimodular gravity: Analytical solutions, late-time acceleration, and cosmological constraints, 2020

[5] I. Prigogine, J. Geheniau, E. Gunzig and P. Nardone, “Thermodynamics and cosmology,” Gen. Rel. Grav.21, 767 (1989) 1989

Formal links

2 machine-checked theorem links

Receipt and verification

First computed	2026-05-20T00:03:19.749764Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

752fc242f6af469cbd68f6538b2df73c9ab01e9c34fa275ae7d50b4082614d68

Aliases

arxiv: 2605.16751 · arxiv_version: 2605.16751v1 · doi: 10.48550/arxiv.2605.16751 · pith_short_12: OUX4EQXWV5DJ · pith_short_16: OUX4EQXWV5DJZPLI · pith_short_8: OUX4EQXW

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/OUX4EQXWV5DJZPLI6ZJYWLPXHS \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: 752fc242f6af469cbd68f6538b2df73c9ab01e9c34fa275ae7d50b4082614d68

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "f33a2bdf62534d28c7f4c252b2f561fa1e558913e98f8b10ace7c0c2f8ebc431",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "gr-qc",
    "submitted_at": "2026-05-16T02:08:01Z",
    "title_canon_sha256": "ba92ba226e7361b9975d6c5eb3e087f15d25fec8882339d048840d9416e138b4"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2605.16751",
    "kind": "arxiv",
    "version": 1
  }
}