Pith Number

pith:KFE42DCF

pith:2026:KFE42DCFLCUSSBLHCJFHTLH6GH

not attested not anchored not stored refs pending

Photon Sphere and Shadow of a Perturbative Black Hole in $f(R,\mathcal{G})$ Gravity

G.G.L. Nashed

Higher-curvature corrections in f(R,G) gravity shift the photon-sphere radius and alter black-hole shadow sizes.

arxiv:2605.10992 v2 · 2026-05-09 · gr-qc

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\usepackage{pith}
\pithnumber{KFE42DCFLCUSSBLHCJFHTLH6GH}

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Record completeness

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3 Author claim open · sign in to claim

4 Citations 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 derive analytic expressions for the shift in the photon-sphere radius and show that higher-curvature terms modify the location of unstable photon orbits, with the Gauss-Bonnet sector producing a more significant contribution than mixed curvature terms.

C2weakest assumption

The analysis assumes that the coupling parameters are small enough for an asymptotic perturbative expansion around the Schwarzschild solution to remain valid throughout the strong-field region.

C3one line summary

Perturbative higher-curvature corrections in f(R,G) gravity shift the photon-sphere radius and black-hole shadow size away from Schwarzschild values, with the Gauss-Bonnet sector contributing more than mixed terms.

Receipt and verification

First computed	2026-05-20T00:03:17.236614Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

5149cd0c4558a9290567124a79acfe31deb3ab327a283935b51cce57b32688e7

Aliases

arxiv: 2605.10992 · arxiv_version: 2605.10992v2 · doi: 10.48550/arxiv.2605.10992 · pith_short_12: KFE42DCFLCUS · pith_short_16: KFE42DCFLCUSSBLH · pith_short_8: KFE42DCF

Agent API

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Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/KFE42DCFLCUSSBLHCJFHTLH6GH \
  | 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: 5149cd0c4558a9290567124a79acfe31deb3ab327a283935b51cce57b32688e7

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "2fe84e34008aed1246d58a2c8508e1bb3937dc6ab5e0d9bc0b05a978e96f01dc",
    "cross_cats_sorted": [],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "gr-qc",
    "submitted_at": "2026-05-09T12:16:37Z",
    "title_canon_sha256": "fe412be1b7aa9802a51fddb8bbb491ac886d690e871a2350c7cdd5a9c62d8244"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2605.10992",
    "kind": "arxiv",
    "version": 2
  }
}