标题： 中子星密度以上的最小声速的界限 显示英文标题

标题： Bounds on the minimum sound speed above neutron star densities

摘要： 我们证明了大质量中子星的存在和QCD的渐近自由性对超密物质的最低声速设定了稳健的上限，这种声速在中子星中无法达到。我们的方法不需要在密度范围$\sim 2-40 n_0$内显式表示状态方程，也不需要概率解释。当中子星的最大质量大于约$2.5M_\odot$时，上限会迅速下降。发现$\sim 3 M_\odot$中子星将强有力地支持高重子密度下的第一类相变。 显示英文摘要

摘要： We show that the existence of massive neutron stars and asymptotic freedom of QCD place robust upper bounds on the lowest sound speed of the ultra-dense matter unattainable in neutron stars. Our approach does not rely on explicitly representing the equation of state in the density range $\sim 2-40 n_0$, and does not require probabilistic interpretations. The upper limit decreases rapidly when the maximum mass of neutron stars is greater than about $2.5M_\odot$. Discovery of $\sim 3 M_\odot$ neutron stars would strongly support first-order phase transitions at high baryon densities