Pith. sign in

REVIEW 3 cited by

Quasar Proper Motions and Low-Frequency Gravitational Waves

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv astro-ph/9610086 v1 pith:F4WSBY4U submitted 1996-10-12 astro-ph

classification astro-ph
keywords motionsgravitationalproperwavesharmonicslimitsmass-energyapparent
verification ladder T0 review T1 audit T2 compute T3 formal

Signed reviews

No signed human review yet.

0 comments
read the original abstract

We report observational upper limits on the mass-energy of the cosmological gravitational-wave background, from limits on proper motions of quasars. Gravitational waves with periods longer than the time span of observations produce a simple pattern of apparent proper motions over the sky, composed primarily of second-order transverse vector spherical harmonics. A fit of such harmonics to measured motions yields a 95%-confidence limit on the mass-energy of gravitational waves with frequencies <2e-9 Hz, of <0.11/h*h times the closure density of the universe.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 3 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. First astrometric constraints on parity-violation in the gravitational wave background

    astro-ph.CO 2025-05 unverdicted novelty 7.0 of 10

    First astrometric constraints on parity-violating SGWB amplitude are reported as h70²ΩV = -0.020 ± 0.025 (Gaia) and -0.004 ± 0.010 (VLBA) at 2σ, consistent with zero, over 4.2e-18 Hz to 1.1e-8 Hz.

  2. Gaia parallax bias via spherical harmonics: A Python tool and discussion of possible causes

    astro-ph.GA 2026-08 conditional novelty 6.0 of 10

    A spherical-harmonic fit to a million quasar parallaxes yields a sky-map correction tool for Gaia DR3, revealing a dipole-like pattern and showing the zero-point leaks into proper motions.

  3. Synergies Between Pulsar Timing Array and Astrometry

    astro-ph.IM 2026-06 unverdicted novelty 4.0 of 10

    Joint SKA PTA and astrometry analysis improves gravitational wave background detection sensitivity by 10-50%.

Pith tools