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Testing gravity with frequency-dependent overlap reduction function in Pulsar Timing Array

delete2024-10-30
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PRE
AI
Q
Qiuyue Liang *
I
Ippei Obata
M
Misao Sasaki
DOI:10.1088/1475-7516/2024/10/097delete
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Abstract

Abstract

En 中文
The positive evidence of a nano-hertz gravitational wave background recently found by several pulsar timing array (PTA) collaborations opened up a window to test modified gravity theories in a unique frequency band in parallel to other gravitational wave detection experiments. In particular, the overlap reduction function (ORF) in PTA observation is sensitive to the phase velocity of gravitational waves. In this work, we provide analytical expressions for the coefficients of the multipole moments in the ORF, and utilize these analytical results to study constraints on the phase velocity from the frequency dependent overlap reduction function obtained from the Chinese PTA (CPTA) data. While the data contain large error bars yet, interesting constraints are found in the frequency-dependent ORF in the case of subluminal phase velocity. This makes us expect that the nano-hertz band gravitational wave background will become one of the important arenas for exploring modified gravity theories.
Keywords:
modified gravity
gravitational waves / experiments
gravitational waves / theory
Gravitational waves in GR and beyond: theory

Journal

Journal of Cosmology and Astroparticle Physics cover
Journal of Cosmology and Astroparticle Physics
IF:
5.9
Papers:
1.3W
Citations:
4.7W

Organization

U
University of Tokyo
Scholars:
7.1W
Papers: 6.5W
Citations: 2.2K