Solar diffraction of LIGO-band gravitational waves

Abstract

We show that chirping gravitational waves in the LIGO frequency band f = 1–5000 Hz can be gravitationally diffracted by the Sun, due to the coincidence of its Fresnel length rF ∝ √1 AU/f and the solar radius r ⊙. This solar diffraction is potentially detectable through its frequency-dependent amplification of the wave. The detection rate with Einstein Telescope is estimated to be ∼ 1/1000 per year, with the optical depth ∝ (solar angular area on the sky)/4π. High-frequency regimes of merger and ringdown phases are found to be crucial. In addition to the discovery, we advocate that solar diffraction allows probing the inner solar density profile, as rF sweeps a range of solar radius during the chirping. These physics are captured by a formalism in terms of convergence and shear, which allows much easier estimation and more intuitive understanding. Solar diffraction can be a new opportunity with ongoing and future LIGO-band missions.

Probing the Solar Interior with Lensed Gravitational Waves from Known Pulsars

“…Therefore, in geometrical optics, the lensing modulations are indistinguishable from the intrinsic source properties (unless lensed signals with various θ s from a single source are available). Figure 3 is consistent with Figure 2 of Jung & Kim (2023).…”

“…Therefore, within the frequency range of ground-based detectors, the solar lensing imprints unique frequency-dependent modulations on both the amplitude and phase. The solar structure can (in principle) be extracted from the chirp signal (see the recent study by Jung & Kim 2023). However, in the high-frequency limit, solar structure extraction from the signal (even from a chirp signal) is impossible at a single θ s because the constant A F is degenerate with an intrinsic amplitude of GWs.…”

“…However, they only roughly estimated the detectability of the lensing signature, without calculating the measurement accuracy of the density profile. Very recently, Jung & Kim (2023) reported that the Fresnel scale is comparable to the solar radius within the frequency band of the ground-based detectors; therefore, the density profile can (in principle) be probed with the lensing modulation on a chirp signal from a CBC.…”

Testing an exact diffraction formula with gravitational wave source lensed by a supermassive black hole in binary systems

“…The sun is nearest massive lens to us. Similar to [23,24], we choose the sun as the lens. In this case, we adopt some typical parameters D L = 1 AU=1.5 × 10 8 km, D LS ∼ D S ≫ D L , source (e.g.…”

“…It offers a unique opportunity to measure the propagation speed of GWs [10,11], constrain cosmological models [12], and shed light on the origins of stellar binary black holes (BHs) [13]. Furthermore, it provides a powerful tool to explore the nature of dark matter [14][15][16][17][18][19][20][21][22] and even the internal structure of the sun [23,24]. The potential applications of detecting GL of GWs are vast and promising, paving the way for exciting new discoveries in the field of gravitational physics.…”