标题： 具有统一相互作用状态方程的正则化4D爱因斯坦-高斯-邦尼引力中的夸克星 显示英文标题

标题： Quark stars with a unified interacting equation of state in regularized 4D Einstein-Gauss-Bonnet gravity

摘要： 自从得到了4D爱因斯坦高斯-博内特（4DEGB）引力与标量场耦合的明确$D\rightarrow 4$极限后，人们对其作为爱因斯坦广义相对论替代方案的兴趣增加。使用针对4DEGB引力修改的托尔曼-奥本海默-沃尔科夫（TOV）方程，我们利用一种新颖的相互作用夸克物质状态方程来模拟夸克星的恒星结构。我们发现，增加高斯-博内特耦合常数$\alpha$或相互作用参数$\lambda$都会倾向于增加该理论描述的夸克星的质量半径曲线，从而使给定的中心压力在一般情况下支持更大的夸克星。这些结果逻辑上扩展到$\lambda < 0$的情况，在这种情况下，增加相互作用效应的大小反而会减小质量和半径。我们还分析地确定了两种情况下的临界中心压力，低于该压力时由于压力函数没有根，不存在夸克星解。最有趣的是，我们发现由于4DEGB中黑洞和致密星之间缺乏质量间隙，夸克星可以存在于广义相对论的布赫达赫尔界限和施瓦茨希尔德半径$R=2M$以下。即使对于当前观测限制内的小$\alpha$，我们发现该理论中的夸克星解可以描述极端致密天体（ECOs），其半径小于广义相对论允许的范围。 显示英文摘要

摘要： Since the derivation of a well-defined $D\rightarrow 4$ limit for 4D Einstein Gauss-Bonnet (4DEGB) gravity coupled to a scalar field, there has been interest in testing it as an alternative to Einstein's general theory of relativity. Using the Tolman-Oppenheimer-Volkoff (TOV) equations modified for 4DEGB gravity, we model the stellar structure of quark stars using a novel interacting quark matter equation of state. We find that increasing the Gauss-Bonnet coupling constant $\alpha$ or the interaction parameter $\lambda$ both tend to increase the mass-radius profiles of quark stars described by this theory, allowing a given central pressure to support larger quark stars in general. These results logically extend to cases where $\lambda < 0$, in which increasing the magnitude of the interaction effects instead diminishes masses and radii. We also analytically identify a critical central pressure in both regimes, below which no quark star solutions exist due to the pressure function having no roots. Most interestingly, we find that quark stars can exist below the general relativistic Buchdahl bound and Schwarzschild radius $R=2M$, due to the lack of a mass gap between black holes and compact stars in 4DEGB. Even for small $\alpha$ well within current observational constraints, we find that quark star solutions in this theory can describe Extreme Compact Objects (ECOs), objects whose radii are smaller than what is allowed by general relativity.