The observation and distinction of two compact stars with an identical mass but a different radius would be a clear sign of hadron-quark phase transition in nuclear matter. Motivated by studies searching for significant deviations in the observables of twin stars, we investigate the differences that manifest in their r-mode instability windows and spin-down evolution. Firstly, we obtain a set of hybrid equations of state (which predict the existence of a third stable branch of compact objects) by employing the well-known Maxwell construction within the phenomenological framework of constant speed of sound parametrization. Then, we systematically study the influence of certain parameters, such as the energy density jump (in the resulting hybrid equation of state) and the crust elasticity, on the deviations appearing in the r-mode instability windows and spin-down evolution of twin stars. We conclude that two stars with an identical mass and fairly similar spin frequency and temperature, may behave differently with respect to r-modes. Thus, the future possible detection of gravitational waves (due to unstable r-modes) from a star laying in the stable region of the frequency-temperature plane would be a strong indication for the existence of twin stars. Furthermore, we consider current data for the spin frequencies and temperatures of observed pulsars and compare them to the predictions made from equations of state employed in this study. We find that, depending on the transition density and the rigidness of the crust, hybrid equations of state may be a viable solution for the explanation of existing data.
Hybrid neutron stars among mass gap objects are excluded by twin stars at $1.4\,M_\odot$
University of Wroclaw（弗罗茨瓦夫大学）；A. Alikhanyan National Science Laboratory（阿利哈尼扬国家科学实验室）；Helmholtz-Zentrum Dresden-Rossendorf (HZDR)（德累斯顿-罗斯多夫亥姆霍兹中心）；Center for Advanced Systems Understanding (CASUS)（高级系统理解中心）；Institute of Independent Studies（独立研究学院）；Institute of Experimental Physics, University of Wroclaw（弗罗茨瓦夫大学实验物理研究所）
Baryon fluctuation signatures of the onset of deconfinement
Jan Kochanowski University（扬·科哈诺夫斯基大学）；Bogolyubov Institute for Theoretical Physics（博戈柳博夫理论物理研究所）；GSI Helmholtzzentrum für Schwerionenforschung（德国重离子研究中心）
High-mass twins & resolution of the reconfinement, masquerade and hyperon puzzles of compact star interiors
我们的目标是有助于解决与致密星致密核结构（CS）有关的三个基本难题：（i）超子难题：如何协调$2\,$ M $_\odot$的脉冲星质量与超子软化状态方程（EoS）;（ii）伪装问题：现代EOS冷，高密度强子和夸克物质几乎是相同的;（iii）的refinement难题：怎么办时，解除禁闭过渡后的强子EOS再次成为有利的？我们表明，考虑到重子的复合性（排除体积和/或夸克泡利阻塞）的强子侧和夸克物质侧的限制和硬化效应的结果在早期的相变到夸克物质，在高密度，消除了所有三个目前的CS内部的困惑。此外，在这类新的EoS的混合CS下降的一个有趣的情况下，一个强的一阶相变，导致可观察到的高质量的双星现象，天体物理观测的一个关键端点的QCD相图。
Columbia Astrophysics Laboratory, Columbia University（哥伦比亚天体物理实验室，哥伦比亚大学）；Institute of Theoretical Physics, University of Wrocław（弗罗茨瓦夫大学理论物理研究所）；Frankfurt Institute for Advanced Studies（法兰克福高等研究院）
Confining density functional approach to the QCD phase diagram at low temperatures and thermal twin stars
University of Wroclaw（弗罗茨瓦夫大学）；Helmholtz-Zentrum Dresden-Rossendorf (HZDR)（德累斯顿-罗斯多夫亥姆霍兹中心）；Center for Advanced Systems Understanding (CASUS)（先进系统理解中心）；Deutsches Zentrum für Astrophysik (DZA)（德国天体物理学中心）
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。
