Twin stars and the stiffness of the nuclear equation of state: ruling out strong phase transitions below $1.7n_0$ with the new NICER radius measurements
We explore the connection between the stiffness of an hadronic equation of state (EoS) with a sharp phase transition to quark matter to its tidal deformability. For this we employ a hadronic relativistic mean field model with a parameterized effective nucleon mass to vary the stiffness in conjunction with a constant speed of sound EoS for quark matter. We compute multiple scenarios with phase transitions according to the four possible cases of a hybrid star EoS with a stable second branch. We demonstrate at the example of GW170817 how the effective nucleon mass can be constrained by using gravitational wave data. We find, that certain values of the effective nucleon mass are incompatible with GW170817 and a phase transition simultaneously. By using the recent NICER measurements of J0030+0451 at the $1σ$ level we constrain our results further and find that strong phase transitions with a visible jump in the mass-radius relation are ruled out at densities below 1.7 times saturation density.
Impact of soft versus hard equations of state on hybrid stars
Université Paris-Saclay（巴黎萨克雷大学）；CNRS/IN2P3, IJCLab（法国国家科学研究中心/法国核物理与粒子物理研究所，IJCLab）；Physics Department, Yildiz Technical University（伊斯坦布尔技术大学物理系）；Faculty of Engineering and Architecture, Istanbul Esenyurt University（伊斯坦布尔埃森尤特大学工程与建筑学院）；Institut Universitaire de France (IUF)（法兰西学院）；International Research Laboratory on Nuclear Physics and Astrophysics, Michigan State University and CNRS（密歇根州立大学与中国国家科学研究中心核物理与天体物理学国际研究实验室）
Bayesian Constraints on Bosonic Dark Matter in Neutron Stars within a Covariant Density-Functional Equation-of-State Ensemble
University of Wrocław（弗罗茨瓦夫大学）；Institute of Theoretical Physics, University of Wrocław（弗罗茨瓦夫大学理论物理研究所）；Alikhanyan National Science Laboratory (Yerevan Institute of Physics)（阿利哈尼扬国家科学实验室（埃里温物理研究所））；Frankfurt Institute for Advanced Studies（法兰克福高级研究所）
Constraining free parameters of a color superconducting non-local Nambu-Jona-Lasinio model using Bayesian analysis of neutron stars mass and radius measurements
The Role of the Core in Setting Massive Neutron-Star Radii
Centro Brasileiro de Pesquisas Físicas（巴西物理研究中心）；Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo（圣保罗大学天文、地球物理与大气科学研究所）；Departamento de Física, Instituto Tecnológico de Aeronáutica（航空技术学院物理系）
Bayesian Inference of Dense-Matter Equations of State from Small-Radius Compact Stars with Twin-Star Scenarios
School of Physics, Nankai University（南开大学物理学院）；Shenzhen Research Institute of Nankai University（南开大学深圳研究院）；Department of Physics, Faculty of Science, Tianjin University（天津大学理学院物理系）
本文通过贝叶斯方法研究致密物质方程 of state，探讨小半径致密星体是否能被双星情景所容纳，通过约束参数发现相变特征及对潮汐变形性的影响。
Universal description of the Neutron Star's surface and its key global properties: A Machine Learning Approach for nonrotating and rapidly rotating stellar models
