The development of emulators for the evaluation of many-body observables has gained increasing attention over the last years. In particular the framework of eigenvector continuation (EC) has been identified as a powerful tool when the Hamiltonian admits for a parametric dependence. By training the emulator on a set of training data the many-body solution for arbitrary parameter values can be robustly predicted in many cases. Furthermore, it can be used to resum perturbative expansions that otherwise diverge. In this work, we apply EC to the pairing Hamiltonian and show that EC-resummed perturbation theory is in qualitative agreement with the exact solution and that EC-based emulators robustly predict the ground-state energy once the training data are chosen appropriately. In particular the phase transition from the normal to the superfluid regime is quantitatively predicted using a very low number of training points.
Facility for Rare Isotope Beams and Department of Physics and Astronomy, Michigan State University（密歇根州立大学稀有同位素束设施与物理和天文学系）；Department of Physics, North Carolina State University（北卡罗来纳州立大学物理系）；Department of Mathematics, North Carolina State University（北卡罗来纳州立大学数学系）；Department of Electrical and Systems Engineering, Department of Computer and Information Science, Department of Bioengineering, University of Pennsylvania（宾夕法尼亚大学电气与系统工程系、计算机与信息科学系、生物工程系）；Department of Physics, University of Guelph（圭尔夫大学物理系）
Toward emulating nuclear reactions using eigenvector continuation
我们构造了一个有效的模拟器，两体散射观测使用一般（复）科恩变分原理和审判波函数来自本征向量延拓。仿真器同时评估与不同边界条件相关联的Kohn变分原理的阵列，其允许检测和去除被称为Kohn异常的伪奇异性。当仅应用于$K$ -矩阵时，我们的仿真器类似于由Reynstahl等人构造的仿真器[Phys. Lett. B 809，135719]，尽管具有减少的数值噪声。经过几个应用程序，真正的潜力，我们模拟微分截面的$^{40}$钙$(n,n)$散射的基础上一个现实的光学潜力和量化模型的不确定性，使用贝叶斯方法。这些计算作为一个原则的证明，为今后的研究，旨在改善光学模型。
Determination of nuclear deformations with an emulator for sub-barrier fusion reactions
Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University（中山大学中法核工程与技术学院）；Department of Physics, Kyoto University（京都大学物理学系）；Institute for Liberal Arts and Sciences, Kyoto University（京都大学教养研究院）；RIKEN Nishina Center for Accelerator-based Science, RIKEN（理化学研究所仁科加速器科学中心）；School of Data Science and Management, Utsunomiya University（宇都宫大学数据科学与管理学部）；Nuclear Data Center, Japan Atomic Energy Agency（日本原子能机构核数据中心）
Hartree-Fock emulators for nuclei: Application to charge radii of $^{48,52}$Ca
Technische Universität Darmstadt（达姆施塔特工业大学）；ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH（极端物质研究所 (EMMI)，GSI 重离子研究中心有限公司）；Max-Planck-Institut für Kernphysik（马克斯·普朗克核物理研究所）
