Pith Number

pith:WIYGSYSB

pith:2026:WIYGSYSBXWMXWPHTXLTVFPN62N

not attested not anchored not stored refs resolved

Revisiting the angular size-redshift cosmological test with milliarcsecond radio structures in active galactic nuclei

Alexander B. Pushkarev, Alexander V. Plavin, Andr\'as Kov\'acs, Kenneth I. Kellermann, Leonid I. Gurvits, Mina Ghodsi Yengejeh, S\'andor Frey, Tatiana A. Koryukova

VLBI data on compact AGN radio sources shows the angular size-redshift relation is physically real and can constrain Ω_m when scatter is low.

arxiv:2604.12936 v1 · 2026-04-14 · astro-ph.CO

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\usepackage{pith}
\pithnumber{WIYGSYSBXWMXWPHTXLTVFPN62N}

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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

✓ 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

The randomization test showed that the posterior distributions from randomized data do not overlap with those from real observations, confirming that the measured angular size--redshift relation is physically meaningful. Simulated mock catalogues indicate that the method is able to constrain Ω_m if the data scatter is below ∼20%.

C2weakest assumption

That the astrophysical model parameter describing the redshift dependence of source angular size can be jointly fitted with Ω_m in a way that yields meaningful cosmological constraints despite the noted degeneracy.

C3one line summary

A tenfold larger sample of AGN radio source sizes confirms a real angular size-redshift relation but indicates that scatter must drop below 20% or samples reach thousands to 100,000 to constrain Ω_m effectively.

References

79 extracted · 79 resolved · 1 Pith anchors

[1] An, T. & Baan, W. A. 2012, ApJ, 760, 77 2012

[2] A., & Wang, A 2025

[3] Bash, F. N. 1968, ApJS, 16, 373 1968

[4] J., Gordon, D., Peck, A 2002

[5] Blandford, R. D. & Rees, M. J. 1978, Phys. Scr, 17, 265 1978

Cited by

1 paper in Pith

SKA$-$VLBI view of AGN jets in the early Universe

Receipt and verification

First computed	2026-06-19T16:10:37.386290Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

b230696241bd997b3cf3bae752bdbed34f395d589e2a2de90ea4b66a8d6009ef

Aliases

arxiv: 2604.12936 · arxiv_version: 2604.12936v1 · doi: 10.48550/arxiv.2604.12936 · pith_short_12: WIYGSYSBXWMX · pith_short_16: WIYGSYSBXWMXWPHT · pith_short_8: WIYGSYSB

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/WIYGSYSBXWMXWPHTXLTVFPN62N \
  | 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: b230696241bd997b3cf3bae752bdbed34f395d589e2a2de90ea4b66a8d6009ef

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "b59ee39740e41074aed5da2c205df4dbe498f97788673a1638d46683b562c96f",
    "cross_cats_sorted": [],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "astro-ph.CO",
    "submitted_at": "2026-04-14T16:26:57Z",
    "title_canon_sha256": "a7f1c217ad8a725e10bcd58128fb782ed98711326555bf14c7e33cdf0285aa36"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2604.12936",
    "kind": "arxiv",
    "version": 1
  }
}