Kinematic Anisotropies in PTA Observations: Analytical Toolkit

Authors

Maximilian Blümke
Kai Schmitz
Tobias Schröder
Deepali Agarwal
Joseph D. Romano, The University of Texas Rio Grande ValleyFollow

Document Type

Article

Publication Date

2-13-2026

Abstract

The reported evidence for an isotropic gravitational-wave background (GWB) from pulsar timing array (PTA) collaborations has motivated searches for extrinsic and intrinsic anisotropies. Kinematic anisotropies may arise as a consequence of a boosted observer moving with respect to the frame in which the GWB appears isotropic. In this work, we present an analytical toolbox to describe the effects of kinematic anisotropies on the overlap reduction function. Our analytical results differ from previous findings at the quadrupole order and are detailed in three appendices. For the first time, we also derive the corresponding auto-correlation using two approaches, taking the pulsar distances to be infinite or finite, respectively. Our formulas can be used in forecasts or Bayesian analysis pipelines.

Comments

© 2026 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.    

Recommended Citation

Blümke, Maximilian, Kai Schmitz, Tobias Schröder, Deepali Agarwal, and Joseph D. Romano. "Kinematic Anisotropies in PTA Observations: Analytical Toolkit." Symmetry 18, no. 2 (2026): 355. https://doi.org/10.3390/sym18020355

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Title

Symmetry

DOI

10.3390/sym18020355