Detecting Chiral Gravitational Wave Background with a Dipole Pulsar Timing Array

TL;DR

This paper proposes a dipole pulsar timing array system that enhances sensitivity to chiral gravitational wave backgrounds and extends the detectable frequency range from nanohertz to microhertz.

Contribution

Introduction of a novel dipole pulsar timing array system (dPTA) that detects parity violation and broadens the frequency sensitivity of gravitational wave background detection.

Findings

dPTA system is sensitive to chiral GWBs in the nanohertz regime.

Numerical sensitivity curves show extended frequency range from nanohertz to microhertz.

Overlap reduction functions derived from cross-correlation enable this sensitivity.

Abstract

The pulsar timing array (PTA) is a powerful technique for detecting nanohertz gravitational wave backgrounds (GWBs). However, conventional PTAs lack sensitivity to parity violation in the GWB. In this work, we propose a dipole pulsar timing array system (dPTA). By deriving the overlap reduction functions (ORFs) from the cross-correlation of timing signals, we find that this system exhibits sensitivity to chiral GWBs in the nanohertz regime. Furthermore, through numerical calculations of its sensitivity curves, we demonstrate that the dPTA extends the detectable frequency range of PTAs for GWBs from the nanohertz to the microhertz regime.