https://doi.org/10.1140/epjc/s10052-024-13097-7
Regular Article - Theoretical Physics
Scalar induced gravitational waves in chiral scalar–tensor theory of gravity
1
School of Physics and Astronomy, Sun Yat-sen University, 519082, Zhuhai, China
2
Henan Academy of Sciences, 450046, Zhengzhou, Henan, China
Received:
18
April
2024
Accepted:
3
July
2024
Published online:
24
July
2024
We study the scalar induced gravitational waves (SIGWs) from a chiral scalar–tensor theory of gravity. The parity-violating (PV) Lagrangian contains the Chern–Simons (CS) term and PV scalar–tensor terms, which are built of the quadratic Riemann tensor term and first-order derivatives of a scalar field. We consider SIGWs in two cases, in which the semi-analytic expression to calculate SIGWs can be obtained. Then, we calculate the fractional energy density of SIGWs with a monochromatic power spectrum for the curvature perturbation. We find that the SIGWs in chiral scalar–tensor gravity behave differently from those in GR before and after the peak frequency, which results in a large degree of circular polarization.
© The Author(s) 2024
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