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Sub-Microarcsecond Astrometry and New Horizons in Relativistic Gravitational Physics

Sergei M. Kopeikin·Carl R. Gwinn
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Abstract

Attaining the limit of sub-microarcsecond optical resolution will completely revolutionize fundamental astrometry by merging it with relativistic gravitational physics. Beyond the sub-microarcsecond threshold, one will meet in the sky a new population of physical phenomena caused by primordial gravitational waves from early universe and/or different localized astronomical sources, space-time topological defects, moving gravitational lenses, time variability of gravitational fields of the solar system and binary stars, and many others. Adequate physical interpretation of these yet undetectable sub-microarcsecond phenomena can not be achieved on the ground of the "standard" post-Newtonian approach (PNA), which is valid only in the near-zone of astronomical objects having a time-dependent gravitational field. We describe a new, post-Minkowskian relativistic approach for modeling astrometric observations having sub-microarcsecond precision and briefly discuss the light-propagation effects caused by gravitational waves and other phenomena related to time-dependent gravitational fields. The domain of applicability of the PNA in relativistic space astrometry is explicitly outlined.

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Sergei M. Kopeikin, Carl R. Gwinn. 2000-04-19. Sub-Microarcsecond Astrometry and New Horizons in Relativistic Gravitational Physics. https://arxiv.org/abs/gr-qc/0004064

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