2021/03/03 by João C. Lobato, Lobato, João C., Isabela S. Matos +7 · 2 voices
Physics and Astronomy · #Pulsars and Gravitational Waves Research #Cosmology and Gravitation Theories #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.2103.02632
We explore different facets of the action of linearized gravitational waves\nin Minkowski spacetime background upon light, under the electromagnetic\ngeometrical optics limit, covering the main aspects: light trajectory\nperturbations, radar distance and light frequency shift. For this purpose, we\nconsider observers comoving with the transverse traceless gauge coordinates. We\ncompute the parametrized null geodesics exchanged between two of these\nobservers, presenting explicitly the constants of motion as functions of\nobservables, determining therefrom both the radar distance between the\nobservers and the electromagnetic round-trip frequency shift caused by the\ngravitational wave. Also, a comparison is made between these results and what\none would obtain by using a frequently adopted hybrid model in which the\nspatial trajectory of light is unchanged. Finally, we revisit and provide an\nexplanation, resorting to the constancy of the phase along a light ray, to the\nfundamental puzzling question of how one is able to detect gravitational waves\nby means of interferometry if both light wavelength and detector arms are\nstretched.\n