Effects of axion interactions on quark stars in 4D Einstein–Gauss–Bonnet gravity
- 1Xi’an Jiaotong University
Abstract
We explore the properties of quark stars by combining the microscopic axion-extended Polyakov–Nambu–Jona-Lasinio model with the macroscopic framework of four-dimensional Einstein–Gauss–Bonnet (4D EGB) gravity. Specifically, axion effects are incorporated through the background phase θ =a/fa θ = a / f a in the thermodynamics of quark matter. Our results show that the inclusion of axion-induced interactions stiffens the quark-matter equation of state, thereby increasing the sound speed and the maximum mass of quark stars. The 4D EGB correction effectively weakens gravitational compression and further modifies the stellar structure, allowing for larger radii and higher maximum masses while reducing the compactness and the surface gravitational redshift. The combined effects can support quark stars above 2 M⊙ , 2 M ⊙ , with mass–radius sequences overlapping the observational regions in the indicative phenomenological comparison. These findings reveal that the interplay between axion-induced modifications of dense quark matter and 4D EGB gravity may provide a viable phenomenological framework for describing massive quark stars.
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BibTeX
@article{zhou2026effects,
title = {{Effects of axion interactions on quark stars in 4D Einstein–Gauss–Bonnet gravity}},
author = {Rui Zhou and Ming-zheng-xuan Wu and Xin-ran Yang and Chong-long Xie and Min Zhou and Zhi-yang Liu and Shi-jun Mao and Guo-yun Shao},
journal = {The European Physical Journal C},
year = {2026},
month = oct,
doi = {10.1140/epjc/s10052-026-16435-z},
url = {https://link.springer.com/article/10.1140/epjc/s10052-026-16435-z},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Effects of axion interactions on quark stars in 4D Einstein–Gauss–Bonnet gravity
AU - Rui Zhou
AU - Ming-zheng-xuan Wu
AU - Xin-ran Yang
AU - Chong-long Xie
AU - Min Zhou
AU - Zhi-yang Liu
AU - Shi-jun Mao
AU - Guo-yun Shao
PY - 2026
DA - 2026/10/15
JO - The European Physical Journal C
DO - 10.1140/epjc/s10052-026-16435-z
UR - https://link.springer.com/article/10.1140/epjc/s10052-026-16435-z
AB - We explore the properties of quark stars by combining the microscopic axion-extended Polyakov–Nambu–Jona-Lasinio model with the macroscopic framework of four-dimensional Einstein–Gauss–Bonnet (4D EGB) gravity. Specifically, axion effects are incorporated through the background phase θ =a/f_a θ = a / f a in the thermodynamics of quark matter. Our results show that the inclusion of axion-induced interactions stiffens the quark-matter equation of state, thereby increasing the sound speed and the maximum mass of quark stars. The 4D EGB correction effectively weakens gravitational compression and further modifies the stellar structure, allowing for larger radii and higher maximum masses while reducing the compactness and the surface gravitational redshift. The combined effects can support quark stars above 2 M_⊙ , 2 M ⊙ , with mass–radius sequences overlapping the observational regions in the indicative phenomenological comparison. These findings reveal that the interplay between axion-induced modifications of dense quark matter and 4D EGB gravity may provide a viable phenomenological framework for describing massive quark stars.
SN - 1434-6044
SN - 1434-6052
ER -