306 research outputs found

    The financing of Italian firms and the credit crunch: findings and exit strategies

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    The aim of the paper is to analyse how credit crunch has modified the traditional bank-firm relationship with a particular attention to the Italian situation. Our analysis reinforces the finding that in Italy, the credit available to the real economy is insufficient in terms not only of quantity but also of quality. The subsequent step is to identify and discuss possible exit strategies for eliminating the credit crunch and to overcome serious intrinsic shortcomings in terms of alternative instruments, markets and intermediaries. In fact, if on the one hand the crisis has revealed the underdevelopment of the Italian financial market, the insufficient role of institutional investors, the embryonic state of the corporate bond markets and the virtual non-existence of commercial paper markets; on the other hand, it could finally provide the opportunity for the development of these channels. The changing role of banks in the new scenario is also analysed as well as the characteristics firms will require to benefit from it

    Directional Limits on Persistent Gravitational Waves from Advanced LIGO’s First Observing Run

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    We employ gravitational-wave radiometry to map the stochastic gravitational wave background expected from a variety of contributing mechanisms and test the assumption of isotropy using data from the Advanced Laser Interferometer Gravitational Wave Observatory’s (aLIGO) first observing run. We also search for persistent gravitational waves from point sources with only minimal assumptions over the 20–1726 Hz frequency band. Finding no evidence of gravitational waves from either point sources or a stochastic background, we set limits at 90% confidence. For broadband point sources, we report upper limits on the gravitational wave energy flux per unit frequency in the range Fα;ΘðfÞ < ð0.1–56Þ × 10−8 erg cm−2 s−1 Hz−1ðf=25 HzÞα−1 depending on the sky location Θ and the spectral power index α. For extended sources, we report upper limits on the fractional gravitational wave energy density required to close the Universe of Ωðf; ΘÞ < ð0.39–7.6Þ × 10−8 sr−1ðf=25 HzÞα depending on Θ and α. Directed searches for narrowband gravitational waves from astrophysically interesting objects (Scorpius X-1, Supernova 1987 A, and the Galactic Center) yield median frequency-dependent limits on strain amplitude of h0 < ð6.7; 5.5; and 7.0Þ × 10−25, respectively, at the most sensitive detector frequencies between 130–175 Hz. This represents a mean improvement of a factor of 2 across the band compared to previous searches of this kind for these sky locations, considering the different quantities of strain constrained in each case

    Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

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    We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5– 20 deg2 requires at least three detectors of sensitivity within a factor of ∼2 of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone

    Corporate governance and inequality: The impact of financialization and shareholder value

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    Copyright © 2017 by Emerald Group Publishing Limited. Purpose - The purpose of this chapter is to analyse how in recent years the rediscovery that extreme inequality is returning to advanced economies and has become widespread. What is at issue are the causes of this inequality. It is becoming clear that the wider population, particularly in Anglo-American economies have not shared in the growing wealth of the countries concerned, and that the majority of this wealth is being transferred on a continuous and systemic basis to the very rich. Corporate governance and the pursuit of shareholder value it is argued has become a major driver of inequality. Methodology/approach - The current statistical evidence produced by leading authorities including the US Federal Reserve, World Economic Forum, Credit Suisse and Oxfam are examined. The policy of shareholder value and the mechanisms by which the distributions from business take place are investigated from a critical perspective. Findings - While the Anglo-American economies are seeing a return to the extremes of inequality last witnessed in the 19th century, the causes of this inequality are changing. In the 19th century great fortunes often were inherited, or derived by entrepreneurs from the ownership and control of productive assets. By the late 20th century as Atkinson, Piketty and Saez (2011) and others have highlighted, the sustained and rapid inflation in top income shares have made a significant contribution to the accelerating rate of income and wealth inequality. Research implications - The intensification of inequality in advanced industrial economies, despite the consistent work of Atkinson and others, was largely neglected until the recent research of Picketty which has attracted international attention. It is now acknowledged widely that inequality is a serious issue; however, the contemporary causes of inequality remain largely unexplored. Practical/social implications - The significance of inequality, now that it is recognized, demands policy and practical interventions. However, the capacity or even willingness to intervene is lacking. Further analysis of the debilitating consequences of inequality in terms of the efficiency and stability of economies and societies may encourage a more robust approach, yet the resolve to end extreme inequality is not present. Originality/value - The analysis of inequality has not been neglected and this chapter represents a pioneering effort to relate the shareholder value orientation now dominant in corporate governance to the intensification of inequality

    GWTC-1: A Gravitational-Wave Transient Catalog of Compact Binary Mergers Observed by LIGO and Virgo during the First and Second Observing Runs

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    We present the results from three gravitational-wave searches for coalescing compact binaries with component masses above 1  M⊙ during the first and second observing runs of the advanced gravitational-wave detector network. During the first observing run (O1), from September 12, 2015 to January 19, 2016, gravitational waves from three binary black hole mergers were detected. The second observing run (O2), which ran from November 30, 2016 to August 25, 2017, saw the first detection of gravitational waves from a binary neutron star inspiral, in addition to the observation of gravitational waves from a total of seven binary black hole mergers, four of which we report here for the first time: GW170729, GW170809, GW170818, and GW170823. For all significant gravitational-wave events, we provide estimates of the source properties. The detected binary black holes have total masses between 18.6−0.7+3.2  M⊙ and 84.4−11.1+15.8  M⊙ and range in distance between 320−110+120 and 2840−1360+1400  Mpc. No neutron star-black hole mergers were detected. In addition to highly significant gravitational-wave events, we also provide a list of marginal event candidates with an estimated false-alarm rate less than 1 per 30 days. From these results over the first two observing runs, which include approximately one gravitational-wave detection per 15 days of data searched, we infer merger rates at the 90% confidence intervals of 110−3840  Gpc−3 y−1 for binary neutron stars and 9.7−101  Gpc−3 y−1 for binary black holes assuming fixed population distributions and determine a neutron star-black hole merger rate 90% upper limit of 610  Gpc−3 y−1

    First measurement of the Hubble Constant from a Dark Standard Siren using the Dark Energy Survey Galaxies and the LIGO/Virgo Binary–Black-hole Merger GW170814

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    International audienceWe present a multi-messenger measurement of the Hubble constant H 0 using the binary–black-hole merger GW170814 as a standard siren, combined with a photometric redshift catalog from the Dark Energy Survey (DES). The luminosity distance is obtained from the gravitational wave signal detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO)/Virgo Collaboration (LVC) on 2017 August 14, and the redshift information is provided by the DES Year 3 data. Black hole mergers such as GW170814 are expected to lack bright electromagnetic emission to uniquely identify their host galaxies and build an object-by-object Hubble diagram. However, they are suitable for a statistical measurement, provided that a galaxy catalog of adequate depth and redshift completion is available. Here we present the first Hubble parameter measurement using a black hole merger. Our analysis results in , which is consistent with both SN Ia and cosmic microwave background measurements of the Hubble constant. The quoted 68% credible region comprises 60% of the uniform prior range [20, 140] km s−1 Mpc−1, and it depends on the assumed prior range. If we take a broader prior of [10, 220] km s−1 Mpc−1, we find (57% of the prior range). Although a weak constraint on the Hubble constant from a single event is expected using the dark siren method, a multifold increase in the LVC event rate is anticipated in the coming years and combinations of many sirens will lead to improved constraints on H 0

    Properties of the Binary Neutron Star Merger GW170817

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    On August 17, 2017, the Advanced LIGO and Advanced Virgo gravitational-wave detectors observed a low-mass compact binary inspiral. The initial sky localization of the source of the gravitational-wave signal, GW170817, allowed electromagnetic observatories to identify NGC 4993 as the host galaxy. In this work, we improve initial estimates of the binary's properties, including component masses, spins, and tidal parameters, using the known source location, improved modeling, and recalibrated Virgo data. We extend the range of gravitational-wave frequencies considered down to 23 Hz, compared to 30 Hz in the initial analysis. We also compare results inferred using several signal models, which are more accurate and incorporate additional physical effects as compared to the initial analysis. We improve the localization of the gravitational-wave source to a 90% credible region of 16  deg2. We find tighter constraints on the masses, spins, and tidal parameters, and continue to find no evidence for nonzero component spins. The component masses are inferred to lie between 1.00 and 1.89  M⊙ when allowing for large component spins, and to lie between 1.16 and 1.60  M⊙ (with a total mass 2.73−0.01+0.04  M⊙) when the spins are restricted to be within the range observed in Galactic binary neutron stars. Using a precessing model and allowing for large component spins, we constrain the dimensionless spins of the components to be less than 0.50 for the primary and 0.61 for the secondary. Under minimal assumptions about the nature of the compact objects, our constraints for the tidal deformability parameter Λ are (0,630) when we allow for large component spins, and 300−230+420 (using a 90% highest posterior density interval) when restricting the magnitude of the component spins, ruling out several equation-of-state models at the 90% credible level. Finally, with LIGO and GEO600 data, we use a Bayesian analysis to place upper limits on the amplitude and spectral energy density of a possible postmerger signal

    Search for eccentric binary black hole mergers with Advanced LIGO and Advanced Virgo during their first and second observing runs

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    When formed through dynamical interactions, stellar-mass binary black holes (BBHs) may retain eccentric orbits (e > 0.1 at 10 Hz) detectable by ground-based gravitational-wave detectors. Eccentricity can therefore be used to differentiate dynamically formed binaries from isolated BBH mergers. Current template-based gravitational-wave searches do not use waveform models associated with eccentric orbits, rendering the search less efficient for eccentric binary systems. Here we present the results of a search for BBH mergers that inspiral in eccentric orbits using data from the first and second observing runs (O1 and O2) of Advanced LIGO and Advanced Virgo. We carried out the search with the coherent WaveBurst algorithm, which uses minimal assumptions on the signal morphology and does not rely on binary waveform templates. We show that it is sensitive to binary mergers with a detection range that is weakly dependent on eccentricity for all bound systems. Our search did not identify any new binary merger candidates. We interpret these results in light of eccentric binary formation models. We rule out formation channels with rates greater than about 100 Gpc−3 yr−1 for e > 0.1, assuming a black hole mass spectrum with a power-law index less than about 2
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