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Record W3101299942

Gravitational Bending of Light Near Compact Objects

2002· article· en· W3101299942 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueCERN Document Server (European Organization for Nuclear Research) · 2002
Typearticle
Languageen
FieldPhysics and Astronomy
TopicPulsars and Gravitational Waves Research
Canadian institutionsCanadian Institute for Theoretical AstrophysicsUniversity of Toronto
Fundersnot available
KeywordsPhysicsAntipodal pointSchwarzschild radiusRADIUSBlack-body radiationNeutron starPulsarCompact starAstrophysicsOpticsGeometryRadiationAccretion (finance)Mathematics
DOInot available

Abstract

fetched live from OpenAlex

A photon emitted near a compact object at an angle $\\alpha$ with respect to the radial direction escapes to infinity at a different angle $\\psi>\\alpha$. This bending of light is caused by a strong gravitational field. We show that, in a Schwarzschild metric, the effect is described by $1-\\cos\\alpha=(1-\\cos\\psi)(1-r_g/R)$ where $R/r_g$ is the emission radius in Schwarzschild units. The formula is approximate and it applies at $R\\geq 2r_g$ only, however at these radii it has amazing accuracy, fully sufficient in many applications. As one application we develop a new formulation for the light bending effects in pulsars. It reveals the simple character of these effects and gives their quantitative description with practically no losses of accuracy (for the typical radius of a neutron star $R=3r_g$ the error is 1%). The visible fraction of a star surface is shown to be $S_v/4\\pi R^2=[2(1-r_g/R)]^{-1}$ which is 3/4 for $R=3r_g$. The instantaneous flux of a pulsar comes from one or two antipodal polar caps that rotate in the visible zone. The pulse produced by one blackbody cap is found to be sinusoidal (light bending impacts the pulse amplitude but not its shape). When both caps are visible, the pulse shows a plateau: the variable parts of the antipodal emissions precisely cancel each other. The pulsed fraction of blackbody emission with antipodal symmetry has an upper limit $A_{max}=(R-2r_g)/(R+2r_g)$. Pulsars with $A>A_{max}$ must be asymmetric.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesInsufficient payload (model declined to judge)
Consensus categoriesInsufficient payload (model declined to judge)
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Theoretical or conceptual · Consensus signal: Theoretical or conceptual
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.271
Threshold uncertainty score0.999

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.001
Science and technology studies0.0010.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0140.001

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.027
GPT teacher head0.303
Teacher spread0.276 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it