High density QCD and Compact stars

(1)强子物质一级相变中混合相的性质。讨论了作为“物质新形态”的核物质中的液气转变、介子凝聚和夸克脱界转变等相变类型。它们几乎都是一阶的。因此，我们必须考虑强子物质中具有多组分的一阶相变，在这种情况下，通常的麦克斯韦构造不能精确地得到热力学定义良好的状态方程（EOS）。吉布斯条件是相平衡的基本条件。结构混合相不仅重子数密度不均匀，而且电荷密度也不均匀。我们对上述三种相变进行了研究，试图找出混合相的突出性质。基于密度泛函理论的思想，我们用数值方法确定了密度分布完全满足吉布斯条件。特别地，我们强调了电荷屏蔽对库仑势的重要作用，它可能引起混合相中几何结构的力学不稳定。在极端情况下，麦克斯韦构造给出的EOS被有效地恢复。这些结果影响了致密恒星内部的基本过程以及致密恒星的体积特性。最近我们发表了一篇关于这些工作的综述论文。(2)夸克物质的磁性。我们已经研究了夸克物质的磁性，作为致密恒星中观测到的磁场的微观起源，基于QCD，这是由最近发现的具有超强磁场的磁星所激发的。作为重要工作之一，我们在《暗物质》一书中发表了一篇综述论文，提出了夸克物质中铁磁性的基本思想，然后讨论了铁磁性与彩色超导的共存以及密度波的产生与手性对称恢复的关系。我们利用费米液体理论进一步研究了夸克物质的磁性。我们用q-q相互作用来评估敏感性，其中交换胶子是通过粒子空穴激发来筛选的。屏蔽效应改善了胶子传播体的红外行为，但横向胶子不受静态屏蔽。我们考察了筛选对易感性的影响。我们现在正在准备一篇论文。在铁磁相中，自旋对称性被自发打破，自旋波以低能激发方式出现。我们现在用螺旋方法研究自旋波。这个问题在理论上很有趣，而且对于磁化和比热的温度依赖性很重要。研究了自旋密度波与恢复手性对称性的关系。在通常的标量阶参量之外，考虑伪标量阶参量，给出了另一种对称恢复方案。少

(1)Properties of the mixed phases in the first order phase transition in hadronic matter. There have been discussed various types of phase transitions, such as liquid-gas transition, kaon condensation and quark deconfinement transition, in nucloear matter as "new form of matter", and. almost all of them are of first order. Thus we must consider the first order phase transitions with multi components in hadronic matter, where the usual Maxwell construction is not accurate to get the thermodynamically well-defined equation of state (EOS). The Gibbs conditions are basic requirement for phase equilibrium. Then the structured mixed phases appears, where not only baryon number density but also charge density are nonuniform. We have studied three phase transitions mentioned above and tried to figure out the outstanding properties of the mixed phase. Based on the idea of the density functional theory we numerically determined the density profiles exactly fulfill the Gibbs conditions. In partic … More ular we have emphasized the important role of the charge screening for the Coulomb potential, which may gives rise to the mechanical instability of the geometrical structures in the mixed phase. In the extreme case the EOS given by the Maxwell construction is effectively recovered. These results affect the elementary processes inside compact stars as well as the bulk properties of compact stars.. Recently we have published a review paper concerning these works. (2)Magnetism of quark matter. We have investigated the magnetic properties of quark matter as a microscopic origin of the magnetic field observed in compact stars, based on QCD, which was stimulated by the recent discoveries of magnetars with superstrong magnetic field. As one of the important works we published a review paper in the book "Dark Matter", where we presented a basic idea about ferromagnetism in quark matter, and then discussed the coexistence of ferromagnetism with color superconductivity and production of density wave in relation to restoration of chiral symmetry. We further studied magnetism in quark matter by the use of Fermi liquid theory. We evaluated susceptibility with q-q interaction, where exchanged gluons are screened by particle-hole excitations. IR behavior of the gluon propagator is improved by the screening effect, but transverse gluons receives no static screening. We examined the screening effect on the susceptibility. We are now preparing a paper. In the ferromagnetic phase rotation symmetry is spontaneously broken, and thereby spin wave is appeared as a low energy excitation mode. We are now studying spin wave by the spiral approach. This subject is theoretically interesting, and moreover important for the temperature dependence of magnetization and specific heat. A possibility of spin density wave has been studied in relation to restoration of chiral symmetry. By considering the pseudoscalar order parameter besides the usual scalar one we presented another scenario for symmetry restoration. Less