Practical approaches to analyzing PTA data: Cosmic strings with six pulsars

Abstract

We search for a stochastic gravitational wave background (SGWB) generated by a network of cosmic strings using six millisecond pulsars from Data Release 2 (DR2) of the European Pulsar Timing Array (EPTA). We perform a Bayesian analysis considering two models for the network of cosmic string loops, and compare it to a simple power-law model which is expected from the population of supermassive black hole binaries. Our main strong assumption is that the previously reported common red noise process is a SGWB. We find that the one-parameter cosmic string model is slightly favored over a power-law model thanks to its simplicity. If we assume a two-component stochastic signal in the data (supermassive black hole binary population and the signal from cosmic strings), we get a $95\%$ upper limit on the string tension of ${\log }_{10}(G\mu )<-9.9$ ($-10.5$) for the two cosmic string models we consider. In extended two-parameter string models, we were unable to constrain the number of kinks. We test two approximate and fast Bayesian data analysis methods against the most rigorous analysis and find consistent results. These two fast and efficient methods are applicable to all SGWBs, independent of their source, and will be crucial for analysis of extended data sets.

14 pages, 6 figures; typo corrected in (5)

References in corpus (50)

• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background
• Search for an isotropic gravitational-wave background with the Parkes Pulsar Timing Array
• Searching for the nano-Hertz stochastic gravitational wave background with the Chinese Pulsar Timing Array Data Release I
• The second data release from the European Pulsar Timing Array III. Search for gravitational wave signals
• The NANOGrav 12.5-year Data Set: Search For An Isotropic Stochastic Gravitational-Wave Background
• European Pulsar Timing Array Limits On An Isotropic Stochastic Gravitational-Wave Background
• The NANOGrav 11-year Data Set: Pulsar-timing Constraints On The Stochastic Gravitational-wave Background
• Gravitational wave bursts from cusps and kinks on cosmic strings
• How generic is cosmic string formation in SUSY GUTs
• The NANOGrav 15-year Data Set: Constraints on Supermassive Black Hole Binaries from the Gravitational Wave Background
• Cosmology with the Laser Interferometer Space Antenna
• The number of cosmic string loops
• The International Pulsar Timing Array second data release: Search for an isotropic Gravitational Wave Background
• On the evidence for a common-spectrum process in the search for the nanohertz gravitational-wave background with the Parkes Pulsar Timing Array
• Cosmological evolution of cosmic string loops
• Cosmic String Interpretation of NANOGrav Pulsar Timing Data
• Common-red-signal analysis with 24-yr high-precision timing of the European Pulsar Timing Array: Inferences in the stochastic gravitational-wave background search
• Probing the gravitational wave background from cosmic strings with LISA
• Has NANOGrav found first evidence for cosmic strings?
• Stochastic gravitational wave background from smoothed cosmic string loops
• Systematic investigation of the expected gravitational wave signal from supermassive black hole binaries in the pulsar timing band
• Constraints on cosmic strings using data from the third Advanced LIGO-Virgo observing run
• Fractal Properties and Small-scale Structure of Cosmic String Networks
• Constraints on cosmic string tension imposed by the limit on the stochastic gravitational wave background from the European Pulsar Timing Array
• Constraints on cosmic strings using data from the first Advanced LIGO observing run
• A Practical Theorem on Gravitational Wave Backgrounds
• Understanding and analysing time-correlated stochastic signals in pulsar timing
• Cosmic string loop distribution on all length scales and at any redshift
• Cosmic string loops in the expanding universe
• CMB constraints on cosmic strings and superstrings
• New advances in the Gaussian-process approach to pulsar-timing data analysis
• Abelian Higgs Cosmic Strings: Small Scale Structure and Loops
• Stochastic gravitational waves from cosmic string loops in scaling
• Decay of Cosmic String Loops Due to Particle Radiation
• The Need For Speed: Rapid Refitting Techniques for Bayesian Spectral Characterization of the Gravitational Wave Background Using PTAs
• Bayesian model selection without evidences: application to the dark energy equation-of-state
• Particle emission and gravitational radiation from cosmic strings: observational constraints
• Search for the Gravitational-wave Background from Cosmic Strings with the Parkes Pulsar Timing Array Second Data Release
• Ultra-low frequency gravitational waves from cosmological and astrophysical processes
• Gravitational wave emission from binary supermassive black holes
• Loop decay in Abelian-Higgs string networks
• Noise analysis in the European Pulsar Timing Array data release 2 and its implications on the gravitational-wave background search
• Cosmic string loop shapes
• Searching for cosmic string induced stochastic gravitational wave background with the Parkes Pulsar Timing Array
• Gravitational wave signatures from kink proliferation on cosmic (super-) strings
• Accurate characterization of the stochastic gravitational-wave background with pulsar timing arrays by likelihood reweighting
• Multi-messenger constraints on Abelian-Higgs cosmic string networks
• Proliferation of sharp kinks on cosmic (super-)string loops with junctions
• Impact of the small-scale structure on the Stochastic Background of Gravitational Waves from cosmic strings

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• Constraints on primordial curvature power spectrum with pulsar timing arrays
• Ultrahigh frequency primordial gravitational waves beyond the kHz: The case of cosmic strings
• From quantum gravity to gravitational waves through cosmic strings
• Primordial magnetic field as a common solution of nanohertz gravitational waves and the Hubble tension
• Revised bounds on local cosmic strings from NANOGrav observations
• Geodesics motion of test particles around Schwarzschild-Klinkhamer wormhole with topological defects and gravitational lensing
• Regularizing the Pulsar Timing Array likelihood: A path towards Fourier Space
• Pulsar timing and polarimetry: results and perspectives
• Probing supermassive black hole scalarization with Pulsar Timing Arrays
• Finite Populations & Finite Time: The Non-Gaussianity of a Gravitational Wave Background
• Breaking the Strings: the signatures of Cosmic String Loop Fragmentation
• Testing No slip model with pulsar timing arrays: NANOGrav and IPTA