Work

Non-Gaussian timing residual skewness in pulsar timing arrays

Year: 2026

Type: preprint

Abstract: Motivated by searches for weak primordial non-Gaussianity in the cosmic microwave background, we investigate perturbative departures from Gaussian stochastic gravitational wave background statistics using pulsar timing arrays. We consider a quadratic ansatz that shows three-point correlations at first order in the nonlinear coupling and covariance corrections at second order. We first examine the ansatz for gravitational wave helicity amplitudes. However, the timing residual bispectrum that this produces is not manifestly invariant under local polarization basis rotations for tensor and vector modes. Then, we formulate a polarization-frame-invariant phenomenological model for detector-projected amplitudes and evaluate its one-pulsar timing residual third moment with a simplified response. Our numerical benchmarks have shown that this gives a very small Gaussian-rms-normalized skewness.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2610.02735

Authors: Bernardo, Reginald Christian, Mandal, Rituparna, Ng, Kin-Wang

Institutions: Max Planck Institute for Gravitational Physics, National Central University, Institute of Astronomy and Astrophysics, Academia Sinica, Institute of Physics, Academia Sinica, Academia Sinica

Language: English

Topic: Pulsars and Gravitational Waves Research

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funder: National Science and Technology Council

OpenAlex ID: W7220377385

Cites: 115

Cited by:

Related to: 10