【讲座题目】Unified neutron star EOSs and neutron star structures in RMF models
【主讲人】夏铖君 扬州大学物理科学与技术学院
【讲座时间】2022年5月 21日 10:00-11:00
【腾讯会议】ID:888691028
【报告人简介】
夏铖君博士2008年于浙江工业大学获学士学位;2011年于北京工业大学获硕士学位;2014年于中国科学院大学获博士学位。2014年-2016年在中国科学院理论物理研究所从事博士后研究;2016年-2022年在浙江大学宁波理工学院工作;2022年起在扬州大学工作。在国内外本领域高水平期刊上发表论文40多篇,主持一项国家自然科学基金,参加一项科技部平方公里阵列射电望远镜(SKA)专项科学预研项目。夏铖君博士主要从事夸克物质、重子物质、及夸克-强子混合物质的研究,应用各类理论及模型工具对致密星、夸克物质团、超核等奇特物质进行了大量研究,对高密物质的各类非均匀结构及夸克-真空/强子界面效应有了一些理解,并在国内和国际会议上受邀报告多次。
【讲座内容简介】
In the framework of Thomas-Fermi approximation, we study systematically the EOSs and microscopic structures of neutron star matter in a vast density range with nb≈ 10-10 -2 fm-3, where various covariant density functionals are adopted, i.e., those with nonlinear self couplings (NL3, PK1, TM1, GM1, MTVTC) and density-dependent couplings (DD-LZ1, DDME-X, PKDD, DD-ME2, DD2, TW99). Six types of nuclear matter structures (droplet, rod, slab, tube, bubble, and uniform) are examined adopting spherical and cylindrical approximations for the Wigner-Seitz cell, where the optimum configurations in β-equilibrium are obtained by searching for the energy minimum at fixed baryon number density nb. It is found that the EOSs generally coincide with each other at nb <10-4-2 fm-3 and 0.1 fm-3 <nb <0.3 fmfm-3, while in other density regions they are sensitive to the effective interactions between nucleons. By adopting functionals with larger slope of symmetry energy L, the curvature parameter Ksym and neutron drip density generally increase, while the droplet size, proton number of nucleus, core-crust transition density, and onset density of non-spherical nuclei decrease. All functionals predict neutron stars with maximum masses exceeding the two-solar-mass limit, while those of DD2, DD-LZ1, DD-ME2, and DDME-X predict optimum neutron star radii according to the observational constraints. Approximate linear correlations between neutron stars’ radii at M = 1.4 M⊙and 2 M⊙, the slope L and curvature parameter Ksym of symmetry energy are observed as well. The results presented here are applicable for the investigations on the structures and evolutions of compact stars in a unified manner.