Measuring test mass acceleration noise in space-based gravitational wave astronomy

Congedo, G.

doi:10.1103/physrevd.91.062006

Cited by 4 publications

(8 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The same principle of combining multiple measurement elements is also true for the planned space-based detector LISA, 17 whose key technologies and instrument noise have been successfully tested with LISA Pathfinder. 18,19 In this case the frequency band is much lower, 0.1 − 100 mHz, with a much bigger armlength, ∼ 10 6 km. A simple argument for going into space is the following.…”

Section: Detectors As Combinations Of the Fundamental Measurement Elementioning

confidence: 88%

“…The full calculation is described in length in Ref. 10, but here we report on the main result. If one works in the reference frame of the receiver -as it should do as measurements are made in this reference frame -and parallel transports all quantities from "e" to "r", the first derivative of the frequency shift with respect to the proper time of the receiver, τ r , yields…”

Section: Measurement Principle: a More Recent Perspectivementioning

confidence: 99%

“…1). [9][10][11] This is composed by only three constituents: two free falling test masses, two accurate clocks, and an accurate spacetime metre stick. As simplified this could be, it would be already enough, with infinite accuracy, to respond to a GW by producing relative acceleration between the test masses, and record this motion.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Detection principle of gravitational wave detectors

Congedo

2017

Int. J. Mod. Phys. D

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Detectors As Combinations Of the Fundamental Measurement Elementioning

confidence: 88%

Section: Measurement Principle: a More Recent Perspectivementioning

confidence: 99%

See 1 more Smart Citation

Detection principle of gravitational wave detectors

Congedo

2017

Int. J. Mod. Phys. D

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is in fact the key for the direct observation of gravitational waves (GW) by interferometer detectors on the ground [1,2] and in space [3], and pulsar timing arrays [4]. Particularly at low frequency, GW detectors are limited by differential forces acting on the test masses [5] and, as such, the derivative of the frequency shift may be a good observable of space-time curvature and, in general, a means to separate true gravitational forces from spurious effects. Recently, two different approaches [6,7] have put forward a formalism that allows the frequency shift to be computed in terms of an integrated measure of curvature.…”

mentioning

confidence: 99%

“…An example of which is found in Ref. [5] where the detector response was given in terms of acceleration, a quantity that is very convenient for marginalising over detector systematics.…”

mentioning

confidence: 99%

Derivative of the light frequency shift as a measure of spacetime curvature for gravitational wave detection

Congedo

2015

Phys. Rev. D

Self Cite

View full text Add to dashboard Cite

The measurement of frequency shifts for light beams exchanged between two test masses nearly in free fall is at the heart of gravitational wave detection. It is envisaged that the derivative of the frequency shift is in fact limited by differential forces acting on those test masses. We calculate the derivative of the frequency shift with a fully covariant, gauge-independent and coordinate-free method. This method is general and does not require a congruence of nearby beams' null geodesics as done in previous work. We show that the derivative of the parallel transport is the only means by which gravitational effects shows up in the frequency shift. This contribution is given as an integral of the Riemann tensor -the only physical observable of curvature-along the beam's geodesic. The remaining contributions are: the difference of velocities, the difference of non-gravitational forces, and finally fictitious forces, either locally at the test masses or non-locally integrated along the beam's geodesic. As an application relevant to gravitational wave detection, we work out the frequency shift in the local Lorentz frame of nearby geodesics.Introduction-The exchange of light beams between (almost) free falling test masses and the measurement of the corresponding frequency shifts (see Fig. 1) is at the heart of any thought (real) experiment devised for measuring in principle (in practice) space-time curvature. It is in fact the key for the direct observation of gravitational waves (GW) by interferometer detectors on the ground [1, 2] and in space [3], and pulsar timing arrays [4]. Particularly at low frequency, GW detectors are limited by differential forces acting on the test masses [5] and, as such, the derivative of the frequency shift may be a good observable of space-time curvature and, in general, a means to separate true gravitational forces from spurious effects. Recently, two different approaches [6,7] have put forward a formalism that allows the frequency shift to be computed in terms of an integrated measure of curvature. This is distinct from earlier attempts that often relied on simplifying assumptions, e.g. metric expansion, geodesic deviation, choice of a preferred coordinate system, or fixing an a priori gauge (see the introduction of Ref.[6] and references therein).The only physical covariant quantity that unambiguously describes the effect of curvature in vacuum is the Riemann tensor [8]. In effect, other general relativistic variables, such as the Ricci tensor and the Ricci scalar are identically zero in vacuum, even in a curved spacetime. Additionally, the Christoffel symbols can be set to zero by a proper change of reference frame and the metric itself is in general gauge dependent [9]. Consequently, all those quantities are not good observables of the true gravitational effect and, as such, they might eventually lead to ambiguous results. Previous work has already pointed out, although in different formulations, that the frequency shift is sensitive to an integrated measure of the Riemann tensor...

show abstract

Euclid preparation

Congedo,

Miller,

Taylor

et al. 2024

A&A

View full text Add to dashboard Cite

is a weak lensing shear measurement method developed for and Stage-IV surveys. It is based on forward modelling in order to deal with convolution by a point spread function (PSF) with comparable size to many galaxies, sampling the posterior distribution of galaxy parameters via Markov chain Monte Carlo, and marginalisation over nuisance parameters for each of the 1.5 billion galaxies observed by We quantified the scientific performance through high-fidelity images based on the Flagship simulations and emulation of the VIS images, realistic clustering with a mean surface number density of $ arcmin^ for galaxies, and $ arcmin^ for stars, and a diffraction-limited chromatic PSF with a full width at half maximum of $ $ and spatial variation across the field of view. measured objects with a density of $ arcmin^ in $4500 deg^2 $. The total shear bias was broken down into measurement (our main focus here) and selection effects (which will be addressed in future work). We found measurement multiplicative and additive biases of $m_1=(-3.6 $, $m_2=(-4.3 $, $c_1=(-1.78 $, and $c_2=(0.09 $; a large detection bias with a multiplicative component of $1.2 $ and an additive component of $-3 $; and a measurement PSF leakage of $ $ and $ $. When model bias is suppressed, the obtained measurement biases are close to requirement and largely dominated by undetected faint galaxies ($-5 $). Although significant, model bias will be straightforward to calibrate given its weak sensitivity on galaxy morphology parameters. is publicly available at

show abstract

Measuring test mass acceleration noise in space-based gravitational wave astronomy

Cited by 4 publications

References 34 publications

Detection principle of gravitational wave detectors

Detection principle of gravitational wave detectors

Derivative of the light frequency shift as a measure of spacetime curvature for gravitational wave detection

Euclid preparation

Contact Info

Product

Resources

About