DOCSLIB.ORG

Modified Gravitational Wave Propagation and the Binary Neutron

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Modified Gravitational Wave Propagation and the Binary Neutron Modified gravitational wave propagation and the binary neutron star mass function Andreas Finke,1 Stefano Foffa,1 Francesco Iacovelli,1 Michele Maggiore,1 and Michele Mancarella1 1D´epartement de Physique Th´eoriqueand Center for Astroparticle Physics, Universit´ede Gen`eve,24 quai Ansermet, CH{1211 Gen`eve4, Switzerland Modified gravitational wave (GW) propagation is a generic phenomenon in modified gravity. It affects the reconstruction of the redshift of coalescing binaries from the luminosity distance measured by GW detectors, and therefore the reconstruction of the actual masses of the component compact stars from the observed (`detector-frame') masses. We show that, thanks to the narrowness of the mass distribution of binary neutron stars, this effect can provide a clear signature of modified gravity, particularly for the redshifts explored by third generation GW detectors such as Einstein Telescope and Cosmic Explorer. In recent years, modified GW propagation has come by eq. (1), in theories with extra dimensions, where it is to attention as one of the most promising ways of test- rather due to the loss of gravitons to the bulk [17, 18]. ing deviations from General Relativity (GR) on cosmo- The modified friction term in eq. (1) changes the evo- logical scales. The effect is encoded in the propagation lution of the GW amplitude in the propagation across equation of gravitational waves (GWs) across cosmologi- cosmological distances. Since, in GR, the amplitude of a cal distances which, in modified gravity theories, can take coalescing binary is proportional to 1=dL, where dL is the the form [1{8]1 luminosity distance, this introduces a bias in the lumi- nosity distance inferred from GW observations. In par- ~00 ~0 2 2~ hA + 2 [1 δ(η)]hA + c k hA = 0 : (1) ticular, if δ(η) < 0, the damping term is stronger and, H − after propagation from the source to the detector, the The difference with respect to GR is given by a non- GW has a smaller amplitude. If interpreted within GR, vanishing function δ(η). Several other modifications with it would therefore appear to come from a distance larger respect to GR are possible in the GW sector. The than its actual distance (and vice versa for δ(η) > 0). It most immediate options are a deviation of the speed of is then useful to introduce a distinction between the stan- GWs from the speed of light, or a graviton mass. Both dard luminosity distance, that, in this context, is called would rather modify the c2k2 term in eq. (1), but are the `electromagnetic luminosity distance' and denoted by em now very significantly constrained: a deviation of the dL , and the luminosity distance extracted from the ob- speed of GWs from the speed of light is excluded at servation of the GWs of a compact binary coalescence, −15 the level cgw c =c < (10 ) by the observation of that is called the `GW luminosity distance' [5] and de- j − j O gw GW170817 [9], while limits on the graviton mass are noted by dL . The two quantities are related by [5,7] in the range (10−32 10−22) eV, depending on the Z z 0 probes used [10O]; several− other modifications, in general gw em dz 0 dL (z) = dL (z) exp 0 δ(z ) ; (2) related to rather specific classes of modified gravity the- − 0 1 + z ories, have been tested or proposed, such as extra polar- where δ(z) δ[η(z)]. A useful parametrization of this ef- izations [11], Lorentz-violating dispersion relations [12], fect, which≡ catches the redshift dependence predicted by parity-violating effects [13], or scale dependent modifica- almost all explicit models in terms of just two parameters tions of the speed of GWs [14]. (Ξ ; n), is obtained writing [7], Modified GW propagation, in the form described by 0 gw eq. (1), was first found in some explicit scalar-tensor theo- dL (z) 1 Ξ0 em = Ξ0 + − n ; (3) arXiv:2108.04065v1 [gr-qc] 9 Aug 2021 ries of the Horndeski class [1{4] and, in [5,7], in non-local dL (z) (1 + z) infrared modifications of gravity (i.e. in theories where gw em the underlying classical action is still GR, but non-local which interpolates between d =dL = 1 as z 0 and L ! terms, relevant in the infrared, are assumed to be gener- an asymptotic value Ξ0 at large z, with a power-law be- ated by non-perturbative effects in the quantum effective havior in a = 1=(1 + z) fixed by n. GR is recovered when action [15]; see [16] for recent review). However, it has Ξ0 = 1 (for all n). The study of explicit modified gravity been understood that the phenomenon is completely gen- models shows that Ξ0 can be significantly different from eral and appears in all best studied modified gravity the- 1. In particular, in non-local gravity it can be as large ories [8]. It also appears, in a different form not described as 1:80 [16, 19], corresponding to a 80% deviation from GR, despite the fact that this model complies with ex- isting observational bounds, that force deviations from GR and from ΛCDM in the background evolution and 1 ~ in the scalar perturbation sector to be at most of a few We use standard notation: hA(η; k) is the Fourier transform of the GW perturbation, h0 = @h=@η where η is conformal time, percent [20, 21]. Thus, the newly opened window of GWs a(η) is the scale factor, H = a0=a, and A = +; × labels the two could give us the best opportunities for testing modified polarizations. gravity and dark energy. 2 Ξ0 = 0.5 Ξ0 = 0.5 17.5 1.6 Ξ0 = 1.8 Ξ0 = 1.8 Ξ0 = 5.5 Ξ0 = 5.5 15.0 1.4 Ξ0 = 1 12.5 1.2 true 10.0 1.0 /M true z GR 7.5 0.8 M 5.0 0.6 0.4 2.5 0.2 0.0 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 zGR ztrue FIG. 1. The redshift ztrue of a source, as a function of the FIG. 2. The ratio of the mass MGR inferred in GR over the value zGR that would be incorrectly inferred using GR if Na- true mass Mtrue, as a function of the redshift ztrue. Here M ture is described by a modified gravity theory with Ξ0 =6 1, represent any mass scale made with the (source-frame) masses for different values of Ξ0 [we set for definiteness n = 1:9 in of the component stars, such as individual component masses, eq. (3), which is a value suggested by non-local gravity.] total mass, or chirp mass. Contrary to quantities such as the speed of GWs or of H0 within ΛCDM. We will see that it can become par- the graviton mass, the limits on the parameter Ξ0 (the ticularly powerful when applied to modified GW propa- main parameter that describes modified GW propaga- gation at 3G detectors, thanks to the fact that modified tion; the power n in eq. (3) only determines the precise GW propagation increases with distance, and ET and form of the interpolation between the asymptotic val- CE can detect BNS up to large redshifts, z 2 3 for ' − ues) are still quite broad. Using the binary neutron star ET, and even z 10 for CE [41]. ∼ (BNS) GW170817, with the redshift determined from the The starting point of our analysis is the fact that GW electromagnetic counterpart, only gives bounds of order detectors measure the GW luminosity distance of the gw Ξ0 < 14 (68% c.l., as all the other limits that we will give source, dL , which is different from the actual electro- em below)∼ [7] (see also [4, 22]). This is because the redshift magnetic luminosity distance dL if, in Nature, Ξ0 = 1. gw em 6 of GW170817 is very small, z 0:01, and d (z)=d (z) The redshift zGR of the source that would be inferred ' L L gw goes to one as z 0, for all Ξ0. A more significant limit, from the measured dL assuming GR and ΛCDM (with ! a given value of H0 and ΩM , that we keep for definiteness +3:2 Ξ0 = 2:1−1:2 ; (4) the same in GR and in the modified gravity theory under consideration), would therefore differ from the true value has been obtained in [23], using binary black hole (BBH) ztrue. The effect is shown in Fig.1, for a range of values coalescences without electromagnetic counterpart (`dark of Ξ0 consistent with eq. (4). We see that the effect can sirens') from the O1, O2 and O3a runs of the LIGO/Virgo become very significant at large redshifts. Collaboration (LVC) and correlating them with the In turn, this affects the reconstruction of the actual GLADE galaxy catalog [24]. An even more stringent masses mi (i = 1; 2) of the component stars (`source- bound is obtained under the tentative identification of frame' masses, as they are called in this context), from the flare ZTF19abanrhr as the electromagnetic counter- the `detector-frame' masses m(det);i (1 + z)mi, that part of the BBH coalescence GW190521, in which case are the quantities directly obtained≡ from the GW ob- +0:9 one gets Ξ0 = 1:8−0:6 [23] (see also [25]). However, this servations. If Nature is described by a modified gravity identification currently is not secure. A comparable limit theory with Ξ0 = 1, the true values of the source-frame 6 have been obtained in [26] using the BBH mass function, masses, mtrue;i, are related to the values of the source- following an idea originally proposed in [27] to infer H0.
Load more

Recommended publications
  • 5 Optical Design
    ET-0106A-10 issue :2 ET Design Study date :January27,2011 page :204of315 5 Optical design 5.1 Description Responsible: WP3 coordinator, A. Freise Put here the description of the content of the section . 5.2 Executive Summary Responsible: WP3 coordinator, A. Freise Put here a summary of the main achievement/statements of this section . 5.3 Review on the geometry of the observatory Author(s): Andreas Freise,StefanHild This section briefly reviews the reasoning behind the shape of current gravitational wave detectors and then discusses alternative geometries which can be of interest for third-generation detectors. We will use the ter- minology introduced in the review of a triangular configuration [220] and discriminate between the geometry, topology and configuration of a detector as follows: The geometry describes the position information of one or several interferometers, defined by the number of interferometers, their location and relative orientation. The topology describes the optical system formed by its core elements. The most common examples are the Michelson, Sagnac and Mach–Zehnder topologies. Finally the configuration describes the detail of the optical layout and the set of parameters that can be changed for a given topology, ranging from the specifications of the optical core elements to the control systems, including the operation point of the main interferometer. Please note that the addition of optical components to a given topology is often referred to as a change in configuration. 5.3.1 The L-shape Current gravitational wave detectors represent the most precise instruments for measuring length changes. They are laser interferometers with km-long arms and are operated differently from many precision instruments built for measuring an absolute length.
    [Show full text]
  • The Einstein Telescope (ET) Is a Proposed Underground Infrastructure to Host a Third- Generation, Gravitational-Wave Observatory
    The Einstein Telescope (ET) is a proposed underground infrastructure to host a third- generation, gravitational-wave observatory. It builds on the success of current, second-generation laser- interferometric detectors Advanced Virgo and Advanced LIGO, whose breakthrough discoveries of merging black holes (BHs) and neutron stars over the past 5 years have ushered scientists into the new era of gravitational-wave astronomy. The Einstein Telescope will achieve a greatly improved sensitivity by increasing the size of the interferometer from the 3km arm length of the Virgo detector to 10km, and by implementing a series of new technologies. These include a cryogenic system to cool some of the main optics to 10 – 20K, new quantum technologies to reduce the fluctuations of the light, and a set of infrastructural and active noise-mitigation measures to reduce environmental perturbations. The Einstein Telescope will make it possible, for the first time, to explore the Universe through gravitational waves along its cosmic history up to the cosmological dark ages, shedding light on open questions of fundamental physics and cosmology. It will probe the physics near black-hole horizons (from tests of general relativity to quantum gravity), help understanding the nature of dark matter (such as primordial BHs, axion clouds, dark matter accreting on compact objects), and the nature of dark energy and possible modifications of general relativity at cosmological scales. Exploiting the ET sensitivity and frequency band, the entire population of stellar and intermediate mass black holes will be accessible over the entire history of the Universe, enabling to understand their origin (stellar versus primordial), evolution, and demography.
    [Show full text]
  • Seismic Characterization of the Euregio Meuse-Rhine in View of Einstein Telescope
    SEISMIC CHARACTERIZATION OF THE EUREGIO MEUSE-RHINE IN VIEW OF EINSTEIN TELESCOPE 13 September 2019 First results of seismic studies of the Belgian-Dutch-German site for Einstein Telescope Soumen Koley1, Maria Bader1, Alessandro Bertolini1, Jo van den Brand1,2, Henk Jan Bulten1,3, Stefan Hild1,2, Frank Linde1,4, Bas Swinkels1, Bjorn Vink5 1. Nikhef, National Institute for Subatomic Physics, Amsterdam, The Netherlands 2. Maastricht University, Maastricht, The Netherlands 3. VU University Amsterdam, Amsterdam, The Netherlands 4. University of Amsterdam, Amsterdam, The Netherlands 5. Antea Group, Maastricht, The Netherlands CONFIDENTIAL Figure 1: Artist impression of the Einstein Telescope gravitational wave observatory situated at a depth of 200-300 meters in the Euregio Meuse-Rhine landscape. The triangular topology with 10 kilometers long arms allows for the installation of multiple so-called laser interferometers. Each of which can detect ripples in the fabric of space-time – the unique signature of a gravitational wave – as minute relative movements of the mirrors hanging at the bottom of the red and white towers indicated in the illustration at the corners of the triangle. 1 SEISMIC CHARACTERIZATION OF THE EUREGIO MEUSE-RHINE IN VIEW OF EINSTEIN TELESCOPE Figure 2: Drill rig for the 2018-2019 campaign used for the completion of the 260 meters deep borehole near Terziet on the Dutch-Belgian border in South Limburg. Two broadband seismic sensors were installed: one at a depth of 250 meters and one just below the surface. Both sensors are accessible via the KNMI portal: http://rdsa.knmi.nl/dataportal/. 2 SEISMIC CHARACTERIZATION OF THE EUREGIO MEUSE-RHINE IN VIEW OF EINSTEIN TELESCOPE Executive summary The European 2011 Conceptual Design Report for Einstein Telescope identified the Euregio Meuse-Rhine and in particular the South Limburg border region as one of the prospective sites for this next generation gravitational wave observatory.
    [Show full text]
  • Stochastic Gravitational Wave Backgrounds
    Stochastic Gravitational Wave Backgrounds Nelson Christensen1;2 z 1ARTEMIS, Universit´eC^oted'Azur, Observatoire C^oted'Azur, CNRS, 06304 Nice, France 2Physics and Astronomy, Carleton College, Northfield, MN 55057, USA Abstract. A stochastic background of gravitational waves can be created by the superposition of a large number of independent sources. The physical processes occurring at the earliest moments of the universe certainly created a stochastic background that exists, at some level, today. This is analogous to the cosmic microwave background, which is an electromagnetic record of the early universe. The recent observations of gravitational waves by the Advanced LIGO and Advanced Virgo detectors imply that there is also a stochastic background that has been created by binary black hole and binary neutron star mergers over the history of the universe. Whether the stochastic background is observed directly, or upper limits placed on it in specific frequency bands, important astrophysical and cosmological statements about it can be made. This review will summarize the current state of research of the stochastic background, from the sources of these gravitational waves, to the current methods used to observe them. Keywords: stochastic gravitational wave background, cosmology, gravitational waves 1. Introduction Gravitational waves are a prediction of Albert Einstein from 1916 [1,2], a consequence of general relativity [3]. Just as an accelerated electric charge will create electromagnetic waves (light), accelerating mass will create gravitational waves. And almost exactly arXiv:1811.08797v1 [gr-qc] 21 Nov 2018 a century after their prediction, gravitational waves were directly observed [4] for the first time by Advanced LIGO [5, 6].
    [Show full text]
  • A Primer on LIGO and Virgo Gravitational Wave Detectors
    A primer on LIGO and Virgo gravitational wave detectors Jo van den Brand, Nikhef and VU University Amsterdam, [email protected] Gravitational Wave Open Data Workshop #2, Paris, April 8, 2019 Interferometric gravitational wave detectors Tiny vibrations in space can now be observed by using the kilometer-scale laser-based interferometers of LIGO and Virgo. This enables an entire new field in science Eleven detections…so far First gravitational wave detection with GW150914 and first binary neutron star GW170817 Event GW150914 Chirp-signal from gravitational waves from two Einsteincoalescing black holes were Telescope observed with the LIGO detectors by the LIGO-Virgo Consortium on September 14, 2015 The next gravitational wave observatory Event GW150914 On September 14th 2015 the gravitational waves generated by a binary black hole merger, located about 1.4 Gly from Earth, crossed the two LIGO detectors displacing their test masses by a small fraction of the radius of a proton Displacement Displacement ( 0.005 0.0025 0.000 Proton radii Proton - 0.0025 - 0.005 ) Proton radius=0.87 fm Measuring intervals must be smaller than 0.01 seconds Laser interferometer detectorsEinstein Telescope The next gravitational wave observatory Laser interferometer detectorsEinstein Telescope The next gravitational wave observatory LIGO Hanford VIRGO KAGRA LIGO Livingston GEO600 Effect of a strong gravitational wave on ITF arm 2Δ퐿 h= = 10−22 퐿 Laser interferometer detectors Michelson interferometer If we would use a single photon and only distinguish between bright and dark fringe, then such an ITF would not be sensitive: −6 휆/2 0.5 ×10 m −10 ℎcrude ≈ = ≈ 10 퐿optical 4000 m Need to do 1012 times better.
    [Show full text]
  • The Virgo Interferometer
    The Virgo Interferometer www.virgo-gw.eu THE VIRGO INTERFEROMETER Located near the city of Pisa in Italy, the Virgo interferometer is the most sensitive gravitational wave detector in Europe. The latest version of the interferometer – the Advanced Virgo – was built in 2012, and has been operational since 2017. Virgo is part of a scientific collaboration of more than 100 institutes from 10 European countries. By detecting and analysing gravitational wave signals, which arise from collisions of black holes or neutron stars millions of lightyears away, Virgo’s goal is to advance our understanding of fundamental physics, astronomy and cosmology. In this exclusive interview, we speak with the spokesperson of the Virgo Collaboration, Dr Jo van den Brand, who discusses Virgo’s achievements, plans for the future, and the fascinating field of gravitational wave astronomy. In February 2016, alongside LIGO, the Virgo Collaboration announced the first direct observation of gravitational waves, made using the Advanced LIGO detectors. Please tell us about the excitement amongst members of Collaboration, and what this discovery meant for Virgo. The discovery of gravitational waves from the merger of two black holes was a great achievement and caused excitement to almost all impassioned scientists. The merger was the most powerful event ever detected and could only be observed with gravitational waves. We showed once and for all that spacetime is a dynamical quantity, and we provided the first direct evidence for CREDIT: EGO/Virgo the existence of black holes. Moreover, we detected the collision and How are observable gravitational The curvature fluctuations are tiny and subsequent coalescence of two black waves generated? cause minor relative length differences.
    [Show full text]
  • Book of Abstracts Ii Contents
    Gravitational Wave Probes of Fundamental Physics Monday, 11 November 2019 - Wednesday, 13 November 2019 Volkshotel, Amsterdam, The Netherlands Book of Abstracts ii Contents Welcome ............................................. 1 Detecting Gauged Lµ − Lτ using Neutron Star Binaries .................. 1 Primordial Gravitational Waves from Modified Gravity and Cosmology .......... 1 Novel signatures of dark matter in laser-interferometric gravitational-wave detectors . 1 Audible Axions ......................................... 2 Gravitational waves and collider probes of extended Higgs sectors ............. 3 Simulating black hole dynamics and gravitational wave emission in galactic-scale simula- tions ............................................. 3 Dark Energy Instabilities induced by Gravitational Waves ................. 3 Probing the Early and Late Universe with the Gravitational-Wave Background . 4 Dark, Cold, and Noisy: Constraining Secluded Hidden Sectors with Gravitational Waves 4 Extreme Dark Matter Tests with Extreme Mass Ratio Inspirals ............... 5 Cosmological Tests of Gravity with Gravitational Waves .................. 5 Gravitational Collider Physics ................................. 5 Radiation from Global Topological Strings using Adaptive Mesh Refinement . 6 Massive black hole binaries in the cosmos .......................... 6 Constraining the speed of gravity using astrometric measurements ............ 7 Cross-correlation of the astrophysical gravitational-wave background with galaxy cluster- ing .............................................
    [Show full text]
  • ET Flyer 2008
    EINSTEIN EINSTEIN ETTELESCOPE ETTELESCOPE The ET science case ET design study participants: ET is planned as a broadband detector, with good sensi- tivity over the frequency range from 1 Hz to 10.000 Hz, Participant organization name Country which promises many interesting classes of sources. Bi- nary neutron stars (NS) will sweep through the detector European Gravitational Observatory Italy-France band from 1 Hz to 4 kHz, the signal lasting for several The Einstein Telescope days as the system inspirals to a catastrophic merger Istituto Nazionale di Fisica Nucleare Italy event. The long observation time will allow to predict the location of the source and the precise merger time Max-Planck-Institut Germany (to within milliseconds) when the system will coalesce, für Gravitationsphysik thereby facilitating simultaneous observation of the final merger of the two neutron stars using all windows of as- Centre National de la France tronomical observation. Binary black hole (BH) mergers Recherche Scientifique will also last for several hours, up to a day, in the detec- tion band of ET again making it possible to observe such University of Birmingham United Kingdom events using optical, radio and other telescopes. University of Glasgow United Kingdom ET will be able to observe binary inspirals with SNR’s of 100’s about once each year. Already a single such NIKHEF The Netherlands ‘gold-plated’ event will help explore the various nonlin- earities of general relativity in ways that would never be Cardiff University United Kingdom possible with terrestrial or solar-system experiments or radio binary-pulsar observations. Moreover, the higher harmonics that are present in the waveform will reveal the nature of the space-time geometry in strong gravi- tational fields (as it results when compact stars merge) European Gravitational Observatory and will help us answer fundamental questions about the end-product of a gravitational collapse.
    [Show full text]
  • Einstein Telescope! in 1916 Einstein Predicted Gravitational Waves As a Consequence of His Theory of General Relativity
    The Einstein-Telescope Listening to the murmurs of the Universe (Status and Prospects) Harald Lück AEI Hannover Max-Planck Institute for Gravitational physics Leibniz Universität Hannover, 17.3.2021 Institute for Gravitational physics Content • Gravitational waves • What are we talking about? • What have we detected so far? • What do we intend to measure? aLIGO + KAGRA • GW Detectors • How do they work? • What have we got? aLIGO+ INDIA AdV+ • How to improve? aLIGO + 3G south • Einstein Telescope! In 1916 Einstein predicted Gravitational Waves as a consequence of his Theory of General Relativity The problem is: ∆퐿 2 퐺 푑2푄 1 ℎ = = 퐿 푐4 푑푡2 푑 with Gravitational waves are ripples 2퐺 = ퟏퟎ−ퟒퟒ푠2푘−1푚−1 in space and time caused by changing 푐4 gravitational fields How big is DL caused by a Gravitational wave? Effect of a gravitational wave on a length of 4km h = h10= -22 Gravitational waves C.Carreau propagate – at the speed of light : ESA and cause Credit measurable changes in the distance between objects “Plus” polarization “Cross” polarization The Gravitational Wave Spectrum Cosmic Strings BH and NS Binaries Supernovae Relic radiation Extreme Mass Ratio Inspirals Supermassive BH Binaries Binaries coalescences Spinning NS 10-16 Hz 10-9 Hz 10-4 Hz 100 Hz 103 Hz Inflation Probe Pulsar timing Space detectors Ground based Source Giles Hammond: Adapted from M. Evans (LIGO G1300662-v4); adapted by H. Lück Working principle of a GW Detector: Michelson Interferometer Credit: MIT/Caltech LIGO Laboratory Lots of external disturbances Power lines Molecule Humans crossing Laser beam Seismic disturbance Wind/Weather Thermal Bath Quantum Back-Action noise Magnetic fields Planes Lightning The advanced GW Network Advanced LIGO Hanford, GEO600, 2011 2015 Advanced LIGO INDIA, 2024 Advanced Virgo 2016 KAGRA 2018 Advanced LIGO Livingston, 2015 Sensitivity improvement LIGO <-> aLIGO 11 “Observation of THE Detection Gravitational Waves from a GW150914 Binary Black Hole Merger” 14.
    [Show full text]
  • Gravitational-Wave Astronomy
    Searching for the Stochastic Gravitational-Wave Background Varenna Course on Gravitational Waves and Cosmology Nelson Christensen Artemis, Observatoire de la Côte d’Azur, Nice July 7, 2017 2 Outline . What is a stochastic gravitational-wave background . How to measure the stochastic background ? . LIGO-Virgo data analysis methods for a stochastic gravitational wave background . Review of Advanced LIGO Observing Run 1 Observations . Implications of the first LIGO detections on the background from BBHs . Cosmological sources for a stochastic background . Astrophysical sources for a stochastic backgroun . O1 stochastic analysis and preliminary results . Non-standard GR stochastic searches . Future Advanced LIGO – Advanced Virgo Observing Runs, O2 Update . LISA . Third generation gravitational wave detectors . Conclusions Review – Cosmic Microwave Background (CMB) Blackbody radiation coming from every point in the sky. Primordial plasma at 379,000 years after Big Bang, T ~ 3000 K. Neutral hydrogen formed – universe became transparent to photons. Universe has expanded, today T = 2.726 K, DT/T ~ 10-5 3 Stochastic Gravitational Wave Background (SGWB) Incoherent superposition of many unresolved sources. Cosmological: » Inflationary epoch, preheating, reheating » Phase transitions » Cosmic strings » Alternative cosmologies Astrophysical: » Supernovae » Magnetars » Binary black holes Potentially could probe physics of the very-early Universe. 4 5 Data Analysis . Assume stationary, unpolarized, isotropic and Gaussian stochastic background . Cross correlate the output of detector pairs to eliminate the noise si = hi + ni where 6 Assumptions About The Stochastic Backrgound ● Stationary ● Gaussian ● Central Limit Theorem – a large ● only depends on number of independent events t-t’ and not t or t’. produces a stochastic process. ● In the frequency domain : ● N-point correlators reduce to sum and differences of two point correlator ● Isotropic ● Like CMB – uniform across the sky.
    [Show full text]
  • Moriond Contribution
    SCIENTIFIC POTENTIAL OF EINSTEIN TELESCOPE B Sathyaprakash18, M Abernathy3, F Acernese4;5, P Amaro-Seoane33;46, N Andersson7, K Arun8, F Barone4;5, B Barr3, M Barsuglia9, M Beker45, N Beveridge3, S Birindelli11, S Bose12, L Bosi1, S Braccini13, C Bradaschia13, T Bulik14, E Calloni4;15, G Cella13, E Chassande Mottin9, S Chelkowski16, A Chincarini17, J Clark18, E Coccia19;20, C Colacino13, J Colas2, A Cumming3, L Cunningham3, E Cuoco2, S Danilishin21, K Danzmann6, R De Salvo23, T Dent18, R De Rosa4;15, L Di Fiore4;15, A Di Virgilio13, M Doets10, V Fafone19;20, P Falferi24, R Flaminio25, J Franc25, F Frasconi13, A Freise16, D Friedrich6, P Fulda16, J Gair26, G Gemme17, E Genin2, A Gennai16, A Giazotto2;13, K Glampedakis27, C Gr¨af6 M Granata9, H Grote6, G Guidi28;29, A Gurkovsky21, G Hammond3, M Hannam18, J Harms23, D Heinert32, M Hendry3, I Heng3, E Hennes45, S Hild3, J Hough4, S Husa44, S Huttner3, G Jones18, F Khalili21, K Kokeyama16, K Kokkotas27, B Krishnan33, T.G.F. Li45, M Lorenzini28, H L¨uck6, E Majorana34, I Mandel35, V Mandic31, M Mantovani13, I Martin3, C Michel25, Y Minenkov19;20, N Morgado25, S Mosca4;15, B Mours37, H M¨uller{Ebhardt6, P Murray3, R Nawrodt3;32, J Nelson3, R Oshaughnessy38, C D Ott39, C Palomba34, A Paoli2, G Parguez2, A Pasqualetti2, R Passaquieti13;40, D Passuello13, L Pinard25, W Plastino42, R Poggiani13;40, P Popolizio2, M Prato17, M Punturo1;2, P Puppo34, D Rabeling10;45, P Rapagnani34;41, J Read36, T Regimbau11, H Rehbein6, S Reid3, F Ricci34;41, F Richard2, A Rocchi19, S Rowan3, A R¨udiger6, L Santamar´ıa23,
    [Show full text]
  • Full Abstract Booklet
    21st International Conference on General Relativity and Gravitation Columbia University in the City of New York July 10th - 15th, 2016 ii Contents Session A1 1 A group theoretic approach to shear-free radiating stars (Gezahegn Zewdie Abebe)................................... 1 Separable metrics and radiating stars (Gezahegn Zewdie Abebe) . 1 Lie point symmetries, vacuum Einstein equations, and Ricci solitons (Mo- hammad Akbar).............................. 2 Open Access Non-Linear Electrodynamics Gedanken Experiment for Mod- ified Zero Point Energy and Planck's Constant, h Bar, in the Begin- ning of Cosmological Expansion, So h(Today) = h(Initial). (Andrew Beckwith) ................................. 2 Solving the Einstein-Maxwell Equations for the Propagation of Relativistic Energy during Kasner and other Anisotropic Early-Universe Models (Brett Bochner).............................. 3 Ergosphere of the Born-Infeld black hole (Nora Breton)........... 3 Elastic waves in spherically symmetric elastic spacetimes (Irene Brito,Jaume Carot, and Estelita Vaz)......................... 3 Cylindrically symmetric inhomogeneous dust collapse (Irene Brito, M. F. A. Da Silva, Filipe C. Mena and N. O. Santos)............ 4 Did GW150914 produce a rotating gravastar? (Cecilia Chirenti) . 4 The Inverse spatial Laplacian of spherically symmetric backgrounds (Karan Fernandes) ................................ 4 Coordinate families for the Schwarzschild geometry based on radial timelike geodesics (Tehani Finch)......................... 5 Rotating black hole
    [Show full text]