Pith Number

pith:2XP2EQNT

pith:2025:2XP2EQNTWI3T6S4GRVWL4ZYV33

not attested not anchored not stored refs pending

Quintessence-dominated cyclic universe with negative cosmological constant

Kazuharu Bamba, Nasr Ahmed

A negative time-varying cosmological constant produces positive energy density and pressure sign flips in quintessence cyclic models.

arxiv:2512.13906 v6 · 2025-12-15 · gr-qc · hep-th

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\usepackage{pith}
\pithnumber{2XP2EQNTWI3T6S4GRVWL4ZYV33}

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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

We show that a physically acceptable evolution with positive energy density can be realized, while negative energy density dominates in case of a positive or zero cosmological constant. In the first model, we demonstrate a sign flipping of the cosmic pressure in a quintessence-dominated universe with no violation of the null energy condition.

C2weakest assumption

The assumption that a negative time-varying cosmological constant can be introduced in a specific functional form that produces positive energy density and the desired cyclic behaviors without additional instabilities or contradictions with observations.

C3one line summary

Two cyclic universe models with negative time-varying cosmological constant achieve positive energy density, pressure sign flip without null energy condition violation in quintessence domination, and phantom divide crossing in a matter-bounce scenario.

Formal links

2 machine-checked theorem links

Receipt and verification

First computed	2026-05-21T01:05:13.499399Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

d5dfa241b3b2373f4b868d6cbe6715def3eace0df954fba30efb7a8ec7e042dc

Aliases

arxiv: 2512.13906 · arxiv_version: 2512.13906v6 · doi: 10.48550/arxiv.2512.13906 · pith_short_12: 2XP2EQNTWI3T · pith_short_16: 2XP2EQNTWI3T6S4G · pith_short_8: 2XP2EQNT

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/2XP2EQNTWI3T6S4GRVWL4ZYV33 \
  | 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: d5dfa241b3b2373f4b868d6cbe6715def3eace0df954fba30efb7a8ec7e042dc

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "932d20af35dd7e6df3d7100852ccd3d49f0ae5270b76d8804ac6d594f6f7fc21",
    "cross_cats_sorted": [
      "hep-th"
    ],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "gr-qc",
    "submitted_at": "2025-12-15T21:23:37Z",
    "title_canon_sha256": "16d9200ae34f168e79c144a5bb83b7a03a5a7ee4ea238ec98b4ede2481682958"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2512.13906",
    "kind": "arxiv",
    "version": 6
  }
}