论文标题
磁场中的辐射速度和夸克相的声速
Speed of Sound for Hadronic and Quark Phases in a Magnetic Field
论文作者
论文摘要
在本文中，我们计算了在不同密度区域的磁化混合中子星内可能存在的三个阶段的声速：低密度下的HADRONIC相位，在中间密度的磁性双性手性密度波（MDCDW）相中的夸克 - 夸克 - 夸克，在中等密度下，在较高的密集袋模型上模拟了Ququark相位。发现声音的速度表现出非单调的行为，这是从小于保形限制（$ c_s^2 <1/3 $）的值，到MDCDW阶段的峰值（$ C_S^2> 1/3 $）的峰值（$ C_S^2> 1/3 $），以最终达到共振限制（$ c_s^2 \ sim 1/3 $），以适用于MIT sim 1/3 $）。同样，在存在磁场的情况下，声音的各向异性速度源自第一原理。这是由于存在磁场存在旋转对称性而产生的系统压力中各向异性的结果。讨论了最低的Landau级别贡献在影响磁化阶段的声音速度方面所起的作用。
In this paper we calculate the speed of sound for three phases that may exist inside a magnetized hybrid neutron star at different density regions: A hadronic phase at low densities, quark-matter in the magnetic dual chiral density wave (MDCDW) phase at intermediate densities and a free-quark phase modeled by the MIT bag model at higher densities. It is found that the speed of sound exhibits a non-monotonic behavior, that goes from values smaller than the conformal limit ($c_s^2 < 1/3$) in the hadronic phase, to peak ($c_s^2 > 1/3$) in the MDCDW phase, to finally reach the conformal limit ($c_s^2 \sim 1/3$) at higher densities for quarks in the MIT bag model. Also, the anisotropic speed of sound in the presence of a magnetic field is derived from first principles. This is a consequence of the anisotropy in the system's pressures produced by the breaking of the rotational symmetry in the presence of a magnetic field. The role played by the lowest Landau level contribution in affecting the speed of sound in the magnetized phases is discussed.
