Probing a stationary non-Gaussian background of stochastic gravitational waves with pulsar timing arrays

Abstract

We introduce the concept of stationary graviton non-Gaussianity (nG), an observable that can be probed in terms of 3-point correlation functions of a stochastic gravitational wave (GW) background. When evaluated in momentum space, stationary nG corresponds to folded bispectra of graviton nG. We determine 3-point overlap functions for testing stationary nG with pulsar timing array GW experiments, and we obtain the corresponding optimal signal-to-noise ratio. For the first time, we consider 3-point overlap functions including scalar graviton polarizations (which can be motivated in theories of modified gravity); moreover, we also calculate 3-point overlap functions for correlating pulsar timing array with ground based GW detectors. The value of the optimal signal-to-noise ratio depends on the number and position of monitored pulsars. We build geometrical quantities characterizing how such ratio depends on the pulsar system under consideration, and we evaluate these geometrical parameters using data from the IPTA collaboration. We quantitatively show how monitoring a large number of pulsars can increase the signal-to-noise ratio associated with measurements of stationary graviton nG.

25 pages,13 figures

References in corpus (12)

• Observational Signatures and Non-Gaussianities of General Single Field Inflation
• Gravitational-wave sensitivity curves
• Science with the space-based interferometer LISA. IV: Probing inflation with gravitational waves
• Enhanced Non-Gaussianity from Excited Initial States
• Probing non-tensorial polarizations of stochastic gravitational-wave backgrounds with ground-based laser interferometers
• Large non-Gaussianities in the Effective Field Theory Approach to Single-Field Inflation: the Trispectrum
• Detection methods for non-Gaussian gravitational wave stochastic backgrounds
• A Semi-Parametric Approach to the Detection of Non-Gaussian Gravitational Wave Stochastic Backgrounds
• Non-Gaussianity analysis of GW background made by short-duration burst signals
• Gaussianity of LISA's confusion backgrounds
• Non-Gaussianity test for discriminating gravitational wave backgrounds around 0.1-1Hz
• Fundamental Physics with the SKA:Strong-Field Tests of Gravity Using Pulsars and Black Holes

Cited by in corpus (12)

• PBHs and secondary GWs from ultra slow roll and punctuated inflation
• Testing the Early Universe with Anisotropies of the Gravitational Wave Background
• New universal property of cosmological gravitational wave anisotropies
• Charting the Nanohertz Gravitational Wave Sky with Pulsar Timing Arrays
• Primordial Stochastic Gravitational Wave Background Anisotropies: in-in Formalization and Applications
• Gravitational wave non-linearities and pulsar-timing array angular correlations
• Toward a test of Gaussianity of a gravitational wave background
• The Impact of Dark Matter on Gravitational Wave Detection by Space-based Interferometers
• Steady state of fast-oscillating neutrinos in an inhomogeneous medium
• Tensor bispectrum mediated by an excited scalar field during inflation
• Search for the non-linearities of gravitational wave background in NANOGrav 15-year data set
• Flattened bispectrum of the scalar-induced gravitational waves