Pith Number

pith:KYT4H77L

pith:2026:KYT4H77LO4VSI2W5Z7DA3DLI3Q

not attested not anchored not stored refs resolved

Revisiting constraints on primordial vector modes and implications for sourced magnetic fields and observed $EB$ power spectrum

Kaito Yura, Kiyotomo Ichiki, Shohei Saga, Shuichiro Yokoyama

Cosmological data tightly bound neutrino-sustained vector modes, showing they cannot source observed magnetic fields or the EB power spectrum.

arxiv:2605.13016 v1 · 2026-05-13 · astro-ph.CO

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\usepackage{pith}
\pithnumber{KYT4H77LO4VSI2W5Z7DA3DLI3Q}

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Record completeness

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2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

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

From an MCMC analysis, we obtain the 95% C.L. upper bounds on the vector-to-scalar ratio as r_v < 1.55×10^{-4} and r_v < 1.04×10^{-2} for the νVI and νOCT modes at k0 = 0.01 Mpc^{-1}. We show that even a fully helical primordial vector mode cannot reproduce the currently observed EB signal while remaining consistent with parity-even CMB constraints.

C2weakest assumption

The assumption that regular primordial vector modes are sustained by the anisotropic stress of free-streaming neutrinos under the specific neutrino velocity isocurvature (νVI) and octupole (νOCT) initial conditions.

C3one line summary

Updated constraints on neutrino-sustained primordial vector modes imply magnetic fields too weak to seed observations and cannot reproduce the EB power spectrum while satisfying parity-even limits.

References

46 extracted · 46 resolved · 26 Pith anchors

[1] Cosmological Magnetic Fields: Their Generation, Evolution and Observation 2013 · arXiv:1303.7121

[2] Rebhan, Large-Scale Rotational Perturbations of a Friedmann Universe with Collisionless Matter and Pri- mordial Magnetic Fields, ApJ392, 385 (1992) 1992

[3] Observable primordial vector modes 2004 · arXiv:astro-ph/0403583

[4] Constraint on the primordial vector mode and its magnetic field generation from seven-year Wilkinson Microwave Anisotropy Probe Observations 2012 · arXiv:1112.4705

[5] Constraining primordial vector mode from B-mode polarization 2014 · arXiv:1405.4810

Receipt and verification

First computed	2026-05-18T03:09:00.124303Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

5627c3ffeb772b246addcfc60d8d68dc3786b9664a032188a4433d8d4868b448

Aliases

arxiv: 2605.13016 · arxiv_version: 2605.13016v1 · doi: 10.48550/arxiv.2605.13016 · pith_short_12: KYT4H77LO4VS · pith_short_16: KYT4H77LO4VSI2W5 · pith_short_8: KYT4H77L

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/KYT4H77LO4VSI2W5Z7DA3DLI3Q \
  | 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: 5627c3ffeb772b246addcfc60d8d68dc3786b9664a032188a4433d8d4868b448

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "f0018ba8ff99285b8e7217c3a5fa1571313489a4129f1c928048d47d0610417c",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "astro-ph.CO",
    "submitted_at": "2026-05-13T05:11:09Z",
    "title_canon_sha256": "f0d962eb3cec9999ee9a555aa02f431469b37c70544bd8ab89e120596959646d"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2605.13016",
    "kind": "arxiv",
    "version": 1
  }
}