Stability of neutron stars in Horndeski theories with Gauss-Bonnet couplings
نویسندگان
چکیده
In Horndeski theories containing a scalar coupling with the Gauss-Bonnet (GB) curvature invariant $R_{\rm GB}^2$, we study existence and linear stability of neutron star (NS) solutions on static spherically symmetric background. For scalar-GB form $\alpha \xi(\phi) R_{\rm where $\xi$ is function field $\phi$, linearly stable stars nontrivial profile without instabilities puts an upper bound strength dimensionless constant $|\alpha|$. To realize maximum masses NSs for (or dilatonic) GB $\alpha_{\rm GB}\phi GB}^2$ typical nuclear equations state, obtain theoretical limit $\sqrt{|\alpha_{\rm GB}|}<0.7~{\rm km}$. This tighter than those obtained by observations gravitational waves emitted from binaries NSs. We also incorporate cubic-order derivative interactions, quartic couplings nonminimal to Ricci besides show that NS satisfying all conditions are present certain ranges constants. regularized 4-dimensional Einstein-GB gravity Kaluza-Klein reduction appropriate rescaling constant, find in this theory suffer strong problem as well Laplacian instability even-parity perturbations. power-law $F(R_{\rm GB}^2)$ models, they pathological interior plagued ghost together asymptotic exterior stars.
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ژورنال
عنوان ژورنال: Physical review
سال: 2022
ISSN: ['0556-2813', '1538-4497', '1089-490X']
DOI: https://doi.org/10.1103/physrevd.106.064008