Author
Ingo Diepholz
Other affiliations: Max Planck Society
Bio: Ingo Diepholz is an academic researcher from Leibniz University of Hanover. The author has contributed to research in topics: Pathfinder & Gravitational wave. The author has an hindex of 17, co-authored 53 publications receiving 1541 citations. Previous affiliations of Ingo Diepholz include Max Planck Society.
Papers
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European Space Agency1, Leibniz University of Hanover2, Paris Diderot University3, Imperial College London4, University of Rome Tor Vergata5, University of Trento6, Airbus Defence and Space7, fondazione bruno kessler8, University of Birmingham9, Institut de Ciències de l'Espai10, ETH Zurich11, UK Astronomy Technology Centre12, INAF13, University of Urbino14, European Space Operations Centre15, University of Zurich16, University of Glasgow17, Polytechnic University of Catalonia18, Goddard Space Flight Center19, University of Florence20
TL;DR: The first results of the LISA Pathfinder in-flight experiment demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density.
Abstract: We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2 +/- 0.1 fm s(exp -2)/square root of Hz, or (0.54 +/- 0.01) x 10(exp -15) g/square root of Hz, with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8 +/- 0.3) fm square root of Hz, about 2 orders of magnitude better than requirements. At f less than or equal to 0.5 mHz we observe a low-frequency tail that stays below 12 fm s(exp -2)/square root of Hz down to 0.1 mHz. This performance would allow for a space-based gravitational wave observatory with a sensitivity close to what was originally foreseen for LISA.
523 citations
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European Space Agency1, Leibniz University of Hanover2, Imperial College London3, Paris Diderot University4, University of Trento5, fondazione bruno kessler6, University of Urbino7, University of Birmingham8, ETH Zurich9, UK Astronomy Technology Centre10, Institut de Ciències de l'Espai11, European Space Operations Centre12, University of Zurich13, University of Glasgow14, Polytechnic University of Catalonia15, Goddard Space Flight Center16, University of Florida17
TL;DR: This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency.
Abstract: In the months since the publication of the first results, the noise performance of LISA Pathfinder has improved because of reduced Brownian noise due to the continued decrease in pressure around the test masses, from a better correction of noninertial effects, and from a better calibration of the electrostatic force actuation. In addition, the availability of numerous long noise measurement runs, during which no perturbation is purposely applied to the test masses, has allowed the measurement of noise with good statistics down to
20
μ
Hz
. The Letter presents the measured differential acceleration noise figure, which is at
(
1.74
±
0.01
)
fm
s
−
2
/
√
Hz
above 2 mHz and
(
6
±
1
)
×
10
fm
s
−
2
/
√
Hz
at
20
μ
Hz
, and discusses the physical sources for the measured noise. This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency.
271 citations
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TL;DR: The eLISA mission as discussed by the authors is the first mission to study the entire universe with gravitational waves, and it will offer a wide view of a dynamic cosmos using gravitational waves as new and unique messengers to unveil The Gravitational Universe.
Abstract: The last century has seen enormous progress in our understanding of the Universe. We know the life cycles of stars, the structure of galaxies, the remnants of the big bang, and have a general understanding of how the Universe evolved. We have come remarkably far using electromagnetic radiation as our tool for observing the Universe. However, gravity is the engine behind many of the processes in the Universe, and much of its action is dark. Opening a gravitational window on the Universe will let us go further than any alternative. Gravity has its own messenger: Gravitational waves, ripples in the fabric of spacetime. They travel essentially undisturbed and let us peer deep into the formation of the first seed black holes, exploring redshifts as large as z ~ 20, prior to the epoch of cosmic re-ionisation. Exquisite and unprecedented measurements of black hole masses and spins will make it possible to trace the history of black holes across all stages of galaxy evolution, and at the same time constrain any deviation from the Kerr metric of General Relativity. eLISA will be the first ever mission to study the entire Universe with gravitational waves. eLISA is an all-sky monitor and will offer a wide view of a dynamic cosmos using gravitational waves as new and unique messengers to unveil The Gravitational Universe. It provides the closest ever view of the early processes at TeV energies, has guaranteed sources in the form of verification binaries in the Milky Way, and can probe the entire Universe, from its smallest scales around singularities and black holes, all the way to cosmological dimensions.
208 citations
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TL;DR: The LISA Pathfinder (LPF) is a science and technology demonstrator planned by the European Space Agency in view of the LISA mission as discussed by the authors, and the progress made in preparing its effective implementation in flight.
Abstract: LISA Pathfinder (LPF) is a science and technology demonstrator planned by the European Space Agency in view of the LISA mission. As a scientific payload, the LISA Technology Package on board LPF will be the most precise geodesics explorer flown as of today, both in terms of displacement and acceleration sensitivity. The challenges embodied by LPF make it a unique mission, paving the way towards the space-borne detection of gravitational waves with LISA. This paper summarizes the basics of LPF, and the progress made in preparing its effective implementation in flight. We hereby give an overview of the experiment philosophy and assumptions to carry on the measurement. We report on the mission plan and hardware design advances and on the progress on detailing measurements and operations. Some light will be shed on the related data processing algorithms. In particular, we show how to single out the acceleration noise from the spacecraft motion perturbations, how to account for dynamical deformation parameters distorting the measurement reference and how to decouple the actuation noise via parabolic free flight.
94 citations
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University of Trento1, European Space Agency2, Max Planck Society3, Paris Diderot University4, Dornier Flugzeugwerke5, Spanish National Research Council6, Autonomous University of Barcelona7, University of Birmingham8, University of Hertfordshire9, University of Glasgow10, ETH Zurich11, European Space Operations Centre12, Imperial College London13, University of Zurich14, Polytechnic University of Catalonia15, University of Florida16
TL;DR: The current status of the LISA Pathfinder mission is described, a precursor mission aimed at demonstrating key technologies for future space-based gravitational wave detectors, like LISA, and performance measurements and analysis of these flight components lead to an expected performance of theLISA Pathfinder which is a significant improvement over the mission requirements.
Abstract: In this paper, we describe the current status of the LISA Pathfinder mission, a precursor mission aimed at demonstrating key technologies for future space-based gravitational wave detectors, like LISA. Since much of the flight hardware has already been constructed and tested, we will show that performance measurements and analysis of these flight components lead to an expected performance of the LISA Pathfinder which is a significant improvement over the mission requirements, and which actually reaches the LISA requirements over the entire LISA Pathfinder measurement band.
74 citations
Cited by
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01 Jan 2005
TL;DR: The Monthly Notices as mentioned in this paper is one of the three largest general primary astronomical research publications in the world, published by the Royal Astronomical Society (RAE), and it is the most widely cited journal in astronomy.
Abstract: Monthly Notices is one of the three largest general primary astronomical research publications. It is an international journal, published by the Royal Astronomical Society. This article 1 describes its publication policy and practice.
2,091 citations
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University of Mississippi1, University of Lisbon2, Institut d'Astrophysique de Paris3, Perimeter Institute for Theoretical Physics4, Sapienza University of Rome5, California Institute of Technology6, University of Cambridge7, Cornell University8, Max Planck Society9, Princeton University10, Montana State University11, University of Oxford12, McMaster University13, University of Aveiro14, University of Tübingen15, Naresuan University16, Rochester Institute of Technology17, University of Oldenburg18, Georgia Institute of Technology19, University of Wisconsin–Milwaukee20, University of Florida21, University of Illinois at Urbana–Champaign22, The Chinese University of Hong Kong23, Northwestern University24, Case Western Reserve University25, Sao Paulo State University26, Cardiff University27, Imperial College London28, Grand Valley State University29, Kyoto University30
TL;DR: In this article, a catalog of modified theories of gravity for which strong-field predictions have been computed and contrasted to Einstein's theory is presented, and the current understanding of the structure and dynamics of compact objects in these theories is summarized.
Abstract: One century after its formulation, Einstein's general relativity (GR) has made remarkable predictions and turned out to be compatible with all experimental tests. Most of these tests probe the theory in the weak-field regime, and there are theoretical and experimental reasons to believe that GR should be modified when gravitational fields are strong and spacetime curvature is large. The best astrophysical laboratories to probe strong-field gravity are black holes and neutron stars, whether isolated or in binary systems. We review the motivations to consider extensions of GR. We present a (necessarily incomplete) catalog of modified theories of gravity for which strong-field predictions have been computed and contrasted to Einstein's theory, and we summarize our current understanding of the structure and dynamics of compact objects in these theories. We discuss current bounds on modified gravity from binary pulsar and cosmological observations, and we highlight the potential of future gravitational wave measurements to inform us on the behavior of gravity in the strong-field regime.
1,066 citations
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TL;DR: In this article, the authors review early universe sources that can lead to cosmological backgrounds of GWs and discuss the basic characteristics of present and future GW detectors, including advanced LIGO, advanced Virgo, the Einstein telescope, KAGRA, and LISA.
Abstract: Gravitational waves (GWs) have a great potential to probe cosmology. We review early universe sources that can lead to cosmological backgrounds of GWs. We begin by presenting proper definitions of GWs in flat space-time and in a cosmological setting (section 2). Following, we discuss the reasons why early universe GW backgrounds are of a stochastic nature, and describe the general properties of a stochastic background (section 3). We recap current observational constraints on stochastic backgrounds, and discuss the basic characteristics of present and future GW detectors, including advanced LIGO, advanced Virgo, the Einstein telescope, KAGRA, and LISA (section 4). We then review in detail early universe GW generation mechanisms, as well as the properties of the GW backgrounds they give rise to. We classify the backgrounds in five categories: GWs from quantum vacuum fluctuations during standard slow-roll inflation (section 5), GWs from processes that operate within extensions of the standard inflationary paradigm (section 6), GWs from post-inflationary preheating and related non-perturbative phenomena (section 7), GWs from first order phase transitions related or not to the electroweak symmetry breaking (section 8), and GWs from general topological defects, and from cosmic strings in particular (section 9). The phenomenology of these early universe processes is extremely rich, and some of the GW backgrounds they generate can be within the reach of near-future GW detectors. A future detection of any of these backgrounds will provide crucial information on the underlying high energy theory describing the early universe, probing energy scales well beyond the reach of particle accelerators.
643 citations
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National Institutes of Natural Sciences, Japan1, National Institute of Information and Communications Technology2, Raman Research Institute3, Waseda University4, Osaka Institute of Technology5, Kyoto University6, Osaka City University7, Japan Aerospace Exploration Agency8, University of Electro-Communications9, Kindai University10, National Institute of Advanced Industrial Science and Technology11, Tokyo Institute of Technology12, Goddard Space Flight Center13, University of Tokyo14, Hiroshima University15, Ochanomizu University16, Liverpool John Moores University17, Nagoya University18, Nihon University19, Rikkyo University20, Tokyo Keizai University21, Yamanashi Eiwa College22, Rochester Institute of Technology23, Stanford University24, California Institute of Technology25, Hirosaki University26, Niigata University27, Tokai University28, Tohoku University29, Osaka University30, National Defense Academy of Japan31, University of Tübingen32, Hosei University33, University of Wisconsin–Milwaukee34, Tokyo University of Science35, University of Birmingham36
614 citations