Targeted search for continuous gravitational waves: Bayesian versus maximum-likelihood statistics

Performance comparison of multi-detector detection statistics in targeted compact binary coalescence GW search

Global network of advanced Interferometric gravitational wave (GW) detectors are expected to be on-line soon. Coherent observation of GW from a distant compact binary coalescence (CBC) with a network of interferometers located in different continents give crucial information about the source such as source location and polarization information. In this paper we compare different multi-detector network detection statistics for CBC search. In maximum likelihood ratio (MLR) based detection approaches, the likelihood ratio is optimized to obtain the best model parameters and the best likelihood ra…

Performance of multi-detector hybrid statistic in targeted compact binary coalescence search

In this paper we compare the performance of two likelihood ratio based detection statistics namely maximum likelihood ratio statistic and {\it hybrid} statistic designed for the detection of gravitational waves from compact binary coalescence using multiple interferometric detector networks. We perform simulations with non-spinning double neutron star binary system and neutron star-black hole binary systems with spinning as well as non-spinning black hole component masses. The binary injections are distributed uniformly in volume up to 1 Gpc. We observe that, on average, the maximum likelihood…

Frequentist versus Bayesian analyses: Cross-correlation as an (approximate) sufficient statistic for LIGO-Virgo stochastic background searches

Sufficient statistics are combinations of data in terms of which the likelihood function can be rewritten without loss of information. Depending on the data volume reduction, the use of sufficient statistics as a preliminary step in a Bayesian analysis can lead to significant increases in efficiency when sampling from posterior distributions of model parameters. Here we show that the frequency integrand of the cross-correlation statistic and its variance are approximate sufficient statistics for ground-based searches for stochastic gravitational-wave backgrounds. The sufficient statistics are …

Running vacuum model versus $Λ$CDM -- a Bayesian analysis

We study the running vacuum model in which the vaccum energy density depends on square of Hubble parameter in comparison with the $Λ$CDM model. In this work, the Bayesian inference method is employed to test against the standard $Λ$CDM model to appraise the relative significance of our model, using the combined data sets, Pantheon+CMB+BAO and Pantheon+CMB+BAO+Hubble data. The model parameters and the corresponding errors are estimated from the marginal likelihood function of the model parameters. Marginalizing over all model parameters with suitable prior, we have obtained the Bayes factor as …

Continuous gravitational wave searches with pulsar timing arrays: Maximization versus marginalization over pulsar phase parameters

Resolvable Supermassive Black Hole Binaries are promising sources for Pulsar Timing Array based gravitational wave searches. Search algorithms for such targets must contend with the large number of so-called pulsar phase parameters in the joint log-likelihood function of the data. We compare the localization accuracy for two approaches: Maximization over the pulsar phase parameters (MaxPhase) against marginalization over them (AvPhase). Using simulated data from a pulsar timing array with 17 pulsars, we find that for weak and moderately strong signals, AvPhase outperforms MaxPhase significantl…

使用GSTLAL管道对致密双星并合进行快速定向引力波后随搜索

Fast targeted gravitational-wave followup search for compact binary mergers using GSTLAL pipeline

提出一种利用GSTLAL管道进行定向引力波搜索的方法，通过结合电磁触发器的天空定位和时间信息，增强对亚阈值引力波信号的探测效率，显著提高与短伽马射线暴等事件相关信号的检测能力。