Sub-Microarcsecond Astrometry and New Horizons in Relativistic Gravitational Physics
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 lightpropagation
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.
Citation
arXiv:gr-qc/0004064v1