Detection principle of gravitational wave detectors

Abstract

With the first two detections in late 2015, astrophysics has officially entered into the new era of gravitational wave observations. Since then, much has been going on in the field with a lot of work focussing on the observations and implications for astrophysics and tests of general relativity in the strong regime. However much less is understood about how gravitational detectors really work at their fundamental level. For decades, the response to incoming signals has been customarily calculated using the very same physical principle, which has proved so successful in the first detections. In this paper we review the physical principle that is behind such a detection at the very fundamental level, and we try to highlight the peculiar subtleties that make it so hard in practice. We will then mention how detectors are built starting from this fundamental measurement element.

Joint cosmological inference of standard sirens and gravitational wave weak lensing

“…Owing to amplitude and frequency modulations induced by the motion of the detector around the Sun (LISA) or Earth (LV and ET), the amplitude of the wave is particularly well measured. As the observed GW strain is inversely proportional to the luminosity distance [20,21], the luminosity distance is determined very accurately.…”

An interacting dark sector and the implications of the first gravitational-wave standard siren detection on current constraints

“…It has long been acknowledged (see, for instance, Schutz (1986); Krolak & Schutz (1987); Chernoff & Finn (1993); Markovic (1993); Finn (1996); Wang & Turner (1997); Thorne (1997); Zhu et al (2001); Holz & Hughes (2005); Dalal et al (2006); ; Nissanke et al (2013)) that gravitationalwave inspiral detections would provide us with invaluable cosmological information. Since the amplitude of a binary's gravitational-wave signal encodes its luminosity distance (Congedo 2017), binary inspirals became known as standard sirens (Schutz 1986), which are the gravitational-wave analogues of type Ia supernovae standard candle measurements. In particular, the determination of the Hubble constant from gravitational-wave standard sirens (Schutz 1986;Krolak & Schutz 1987;Chernoff & Finn 1993;Finn 1996;Dalal et al 2006;Nissanke et al 2013) was demonstrated for the first time by the nearly concurrent joint observations of the electromagnetic counterpart (see Abbott et al (2017c,d); Goldstein et al (2017); Soares-Santos et al (2017); Coulter et al (2017); Savchenko et al (2017); Valenti et al (2017); Arcavi et al (2017); Tanvir et al (2017), and references therein) to the gravitational-wave signal (Abbott et al 2017a) produced by the merger of the binary neutron star system GW170817 which has been localised to the host galaxy NGC 4993.…”

“…It has long been acknowledged (see, for instance, Schutz (1986); Krolak & Schutz (1987); Chernoff & Finn (1993); Markovic (1993); Finn (1996); Wang & Turner (1997); Thorne (1997); Zhu et al (2001); Holz & Hughes (2005); Dalal et al (2006); ; Nissanke et al (2013)) that gravitationalwave inspiral detections would provide us with invaluable cosmological information. Since the amplitude of a binary's gravitational-wave signal encodes its luminosity distance (Congedo 2017), binary inspirals became known as standard sirens (Schutz 1986), which are the gravitational-wave analogues of type Ia supernovae standard candle measurements. In particular, the determination of the Hubble constant from gravitational-wave standard sirens (Schutz 1986;Krolak & are expected to be significantly improved after the detection of additional standard siren events.…”