119247738
Measuring the redshift of standard sirens using the neutron star deformability
A recent study has shown that redshift information can be directly extracted from gravitational wave sources. This can be done by exploiting the tidal phasing contributions to the waveform during the inspiral phase of binary neutron stars coalescences. The original study investigated the viability of this idea in the context of the Einstein Telescope using a Fisher Matrix approach and in this paper, we further explore this idea using realistic simulations and Bayesian inference techniques. We find that the fractional accuracy with which the redshift can be measured is in the order of tens of percent, in agreement with Fisher Matrix predictions. Moreover, no significant bias is found. We conclude that, when tidal phasing contributions are included in the analysis, inference of the cosmological parameters from gravitational waves is possible
118398003
Scientific potential of Einstein Telescope
The advanced interferometer network will herald a new era in observational astronomy. There is a very strong science case to go beyond the advanced detector network and build detectors that operate in a frequency range from 
1 Hz to 10 kHz, with sensitivity a factor 10 better in amplitude. Such detectors will be able to probe a range of topics in nuclear physics, astronomy, cosmology 
and fundamental physics, providing insights into many unsolved problems in these areas.
59497924
Towards a generic test of the strong field dynamics of general relativity using compact binary coalescence: Further investigations
In this paper we elaborate on earlier work by the same authors in which a novel Bayesian inference framework for testing the strong-field dynamics of General Relativity using coalescing compact binaries was proposed. Unlike methods that were used previously, our technique addresses the question whether one or more 'testing coefficients' (e.g. in the phase) parameterizing deviations from GR are non-zero, rather than all of them differing from zero at the same time. The framework is well-adapted to a scenario where most sources have low signal-to-noise ratio, and information from multiple sources as seen in multiple detectors can readily be combined. In our previous work, we conjectured that this framework can detect generic deviations from GR that can in principle not be accomodated by our model waveforms, on condition that the change in phase near frequencies where the detectors are the most sensitive is comparable to that induced by simple shifts in the lower-order phase coefficients of more than a few percent (~ 5 radians at 150 Hz). To further support this claim, we perform additional numerical experiments in Gaussian and stationary noise according to the expected Advanced LIGO/Virgo noise curves, and coherently injecting signals into the network whose phasing differs structurally from the predictions of GR, but with the magnitude of the deviation still being small. We find that even then, a violation of GR can be established with good confidence.
122803437
Effect of calibration errors on Bayesian parameter estimation for gravitational wave signals from inspiral binary systems in the advanced detectors era: Further investigations
By 2015, the advanced versions of the gravitational wave detectors Virgo and LIGO will be online. They will collect data in coincidence with enough sensitivity to potentially deliver multiple detections of gravitational waves from inspirals of compact-object binaries. In a previous work, we have studied the effects introduced in the estimation of the physical parameters of the source by uncertainties in the calibration of the interferometers. Our bias estimator for parameter errors introduced by calibration uncertainties consisted of two terms: A genuine bias due to the calibration errors, and a contribution coming from the limited number of samples used to explore the parameter space. In this article, we have focused on this second term, and we have shown how it is smaller than the former (about 10 times smaller), and how it decreases as the signal-to-noise ratio increases.
123983687
Extracting Physics from Gravitational Waves: Testing the Strong-field Dynamics of General Relativity and Inferring the Large-scale Structure of the Universe
1506194
TIGER: A data analysis pipeline for testing the strong-field dynamics of general relativity with gravitational wave signals from coalescing compact binaries
The direct detection of gravitational waves with upcoming second-generation gravitational wave observatories such as Advanced LIGO and Advanced Virgo will allow us to probe the genuinely strong-field dynamics of general relativity (GR) for the first time. We have developed a data analysis pipeline called TIGER (test infrastructure for general relativity), which uses signals from compact binary coalescences to perform a model-independent test of GR. In this paper we focus on signals from coalescing binary neutron stars, for which sufficiently accurate waveform models are already available which can be generated fast enough on a computer that they can be used in Bayesian inference. By performing numerical experiments in stationary, Gaussian noise, we show that for such systems, TIGER is robust against a number of unmodeled fundamental, astrophysical, and instrumental effects, such as differences between waveform approximants, a limited number of post-Newtonian phase contributions being known, the effects of neutron star tidal deformability on the orbital motion, neutron star spins, and instrumental calibration errors.
121504005
HXMT: A Chinese High-Energy Astrophysics Mission
The Hard X-ray Modulation Telescope mission HXMT is mainly devoted to performing a hard X-ray all-sky imaging survey with both high sensitivity and high spatial resolution In the energy range of 20 - 250 keV HXMT can perform full-sky hard X-ray survey with angular resolution 5 prime position accuracy 1 prime and sensitivity better than Integral IBIS and Swift BAT HXMT can also make high signal-to-noise ratio pointing observations of scientific hot spot sources with sensitivity sim 3 0 times 10 -7 ph cm -2 s -1 keV -1 3 100keV 10 5 s for detailed temporal and spectral studies HXMT was selected in 2000 as a project under the Major State Basic Research Program of China for its feasibility and technical demonstration study and in October 2005 HXMT entered the full design phase and was listed as a candidate for the first dedicated astronomy satellite around 2010
118358517
MODEL-INDEPENDENT DETERMINATION OF CURVATURE PARAMETER USING H(z) AND D-A (z) DATA PAIRS FROM BAO MEASUREMENTS
We present a model-independent determination of the curvature parameter Omega(k) using the Hubble parameter H(z) and the angular diameter distance D-A(z) from recent baryon acoustic oscillation (BAO) measurements. Each H(z) and D-A(z) pair from a BAO measurement can constrain a curvature parameter. The accuracy of the curvature measurement improves with increased redshift of H(z) and D-A(z) data. By using the H(z) and D-A(z) pair derived from a BAO Lyman a forest measurement at z = 2.36, the Omega(k) is confined to be -0.05 +/- 0.06, which is consistent with the curvature of -0.037(-0.042) (+0.044) constrained by the nine year Wilkinson Microwave Anisotropy Probe data only. Considering future BAOmeasurements, at least one order of magnitude improvement of this curvature measurement can be expected.
119226523
Missing completely of the CMB quadrupole in WMAP data
In cosmic microwave background (CMB) experiments, foreground-cleaned temperature maps are still contaminated by the residual dipole due to uncertainties of the Doppler dipole direction and microwave radiometer sidelobe. To obtain reliable CMB maps, such contamination has to be carefully removed from observed data. We have previously built a software package for map-making, residual dipole-contamination removal, and power spectrum estimation from the Wilkinson Microwave Anisotropy Probe (WMAP) raw data. This software has now been significantly improved. With the improved software, we obtain a negative result of CMB quadrupole detection with the WMAP raw data, which is −3.2±3.5 μK2 from the seven-year WMAP (WMAP7) data. This result is evidently incompatible with ∼1000 μK2 expected from the standard cosmological model ΛCDM. The completely missing of CMB quadrupole poses a serious challenge to the standard model and sets a strong constraint on possible models of cosmology. Due to the importance of this result for understanding the origin and early evolution of our universe, the software codes we used are opened for public checking.
16231433
Temporal and spectral properties of gamma-ray flashes
[1] The temporal and spectral properties of terrestrial gamma-ray flashes (TGFs) are studied. The delay of low energy photons relative to high energy ones in the γ-ray variations of the TGFs with high signal to noise ratio has been revealed by an approach of correlation analysis in the time domain on different time scales. The temporal structures of the TGFs in high energy band are usually narrower than that in low energy band. The spectral hardness has a general trend of decreasing with time in a flash. The observed temporal and spectral characteristics give constraints and valuable hints on the flash production mechanism.
53526002
Improvement of the low energy neutrino factory
The low energy neutrino factory has been proposed as a very sensitive setup for future searches for CP violation and matter effects. Here we study how its performance is affected when the experimental specifications of the setup are varied. Most notably, we have considered the addition of the ‘platinum’ �µ ! �e channel. We find that, whilst theoretically the extra channel provides very useful complementary information and helps to lift degeneracies, its practical usefulness is lost when considering realistic background levels. Conversely, an increase in statistics in the ‘golden’ �e ! �µ channel and, to some extent, an improvement in the energy resolution, lead to an important increase in the performance of the facility, given the rich energy dependence of the ‘golden’ channel at these energies. We show that a low energy neutrino factory with a baseline of 1300 km, muon energy of 4.5 GeV, and either a 20 kton totally active scintillating detector or 100 kton liquid argon detector, can have outstanding sensitivity to the neutrino oscillation parameters �13, � and the mass hierarchy. For our estimated exposure of 2.8×10 23 kton × decays per muon polarity, the low energy