Pith Number

pith:TRMBYNIX

pith:2026:TRMBYNIXZPAFQE6NSIIZXZQL5P

not attested not anchored not stored refs resolved

Which Neutron Stars Reach the Stiffening Regime? Multimessenger Constraints on Core Sound Speed and Stellar-Mass Thresholds

Nicol\'as Viaux, Sebasti\'an Mendizabal

Multimessenger data show neutron star core stiffening typically begins near 1.6 solar masses.

arxiv:2604.07542 v1 · 2026-04-08 · astro-ph.HE · astro-ph.SR · hep-ph · nucl-th

Open paper page JSON Open Graph Bundle Merged state Verified badge What is a Pith Number?

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{TRMBYNIXZPAFQE6NSIIZXZQL5P}

Prints a linked badge after your title and injects PDF metadata. Compiles on arXiv. Learn more · Embed verified badge

Record completeness

1 Bitcoin timestamp

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

Posterior-resampled exact Tolman-Oppenheimer-Volkoff solutions show that the onset density of the inferred stiffening is typically reached near 1.6 M_⊙, whereas the peak region is accessed only near 2.1 M_⊙. A J0740-like 2.07 M_⊙ pulsar reaches the onset in 91% of posterior draws but the peak in only 46%.

C2weakest assumption

That the four chosen families of equations of state (smooth peaked, monotonic, piecewise, transition-capable) together span the relevant physics without systematic bias from missing degrees of freedom or phase transitions not captured by the parameterization.

C3one line summary

Multimessenger data favor core stiffening that typically starts near 1.6 solar masses and reaches its peak near 2.1 solar masses, with a 2.07-solar-mass pulsar accessing the onset in 91% of draws but the peak in only 46%.

References

19 extracted · 19 resolved · 0 Pith anchors

[1] A. Kurkela, P. Romatschke, and A. Vuorinen, Cold Quark Matter, Phys. Rev. D81, 105021 (2010) 2010

[2] E. S. Fraga, A. Kurkela, and A. Vuorinen, Interacting quark matter equation of state for compact stars, Astro- phys. J. Lett.781, L25 (2014) 2014

[3] T. Gorda, A. Kurkela, R. Paatelainen, S. S¨ appi, and A. Vuorinen, Soft Interactions in Cold Quark Matter, Phys. Rev. Lett.127, 162003 (2021) 2021

[4] E. Annala, T. Gorda, A. Kurkela, and A. Vuorinen, Gravitational-Wave Constraints on the Neutron-Star- Matter Equation of State, Phys. Rev. Lett.120, 172703 (2018) 2018

[5] E. Annala, T. Gorda, J. Hirvonen, A. Kurkela, J. N¨ attil¨ a, and A. Vuorinen, Strongly interacting matter exhibits deconfined behavior in neutron stars, Nat. Commun.14, 8451 (2023) 2023

Receipt and verification

First computed	2026-05-28T02:04:47.396797Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

9c581c3517cbc05813cd92119be60bebcf48d94fb5b61b5dd9cf500effe11cb0

Aliases

arxiv: 2604.07542 · arxiv_version: 2604.07542v1 · doi: 10.48550/arxiv.2604.07542 · pith_short_12: TRMBYNIXZPAF · pith_short_16: TRMBYNIXZPAFQE6N · pith_short_8: TRMBYNIX

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/TRMBYNIXZPAFQE6NSIIZXZQL5P \
  | 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: 9c581c3517cbc05813cd92119be60bebcf48d94fb5b61b5dd9cf500effe11cb0

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "e5ea2f69b9b00c92fb96e436547f27d29aa0f47eee9dffcb13ad8b72e3e570c2",
    "cross_cats_sorted": [
      "astro-ph.SR",
      "hep-ph",
      "nucl-th"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "astro-ph.HE",
    "submitted_at": "2026-04-08T19:37:25Z",
    "title_canon_sha256": "a7be5e6e09b03b01e33a71e87b976792166fb14cc1c5fe2a829b333766e92e4f"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2604.07542",
    "kind": "arxiv",
    "version": 1
  }
}