The input to the configuration-interaction shell model includes many dozens or hundreds of independent two-body matrix elements. Previous studies have shown that when fitting to experimental low-lying spectra, the greatest sensitivity is to only a few linear combinations of matrix elements. Here we consider interactions drawn from the two-body random ensemble, or TBRE, and find that the low-lying spectra are also most sensitive to only a few linear combinations of two-body matrix elements, in a fashion nearly indistinguishable from an interaction empirically fit to data. We find in particular the spectra for both the random and empirical interactions are sensitive to similar matrix elements, which we analyze using monopole and contact interactions.
Weak sensitivity of three-body ($d,p$) reactions to $np$ force models
用绝热扭曲波近似研究三体$(d,p)$转移反应[G.W.北卡贝利J.A. Tostevin，Phys. Rev. Lett. 117，162502（2016）]报道了当核子-核光学势为非局域时，截面对中子-质子$(np)$相互作用模型的强敏感性。本工作的目的是使用更可靠的方法来验证这一不寻常的发现。采用严格的Faddeev型三体散射理论研究了$(d,p)$转移反应。跃迁算子方程在动量空间分波框架下求解。利用非局域核光学势和一些实际的$np$势计算了$^{26}$ Al $(d,p)^{27}$ Al反应的微分截面.仅观察到对$np$力模型的弱依赖性，通常比先前的ADWA研究低一个数量级。实验数据的角分布的形状被很好地再现。用严格的三体方法计算的$(d,p)$转移反应的横截面对$np$相互作用模型的敏感性很小。这表明在非局部电位的背景下ADWA失败。指出了ADWA的一些明显的缺陷。
Regularities of Many-body Systems Interacting by a Two-body Random Ensemble
所有偶偶核的基态都有角动量$I$，等于零，I=0，和正宇称$π=+$。这一特征被认为是核子间吸引性短程相互作用的结果。然而，在二体随机相互作用的存在下，$I^π=0^+$基态（0 g.s.）被发现是强大的玻色子和偶数的费米子。对于简单的系统，例如$d$玻色子、$sp$玻色子、$sd$玻色子和小$j$的单个$j$壳层中的一些费米子，存在一些方法来预测和/或解释自旋$I$基态（$I$ g. s.）概率预测$I$ g.s.的经验方法概率适用于一般情况，例如单个$j$（$j>7/2$）或多个$j$壳层和各种玻色子系统中的费米子，但对0 g. s的鲁棒性有更基本的理解。主导地位仍然遥不可及。进一步有趣的结果也进行了审查有关的其他强大的现象，多体系统的存在下的随机两体相互作用，如奇偶交错的结合能，一般集体，平均能量的行为，相关性，和多体系统相互作用的位移两体随机系综。
Many-body Systems Interacting via a Two-body Random Ensemble (I): Angular Momentum distribution in the ground states
本文讨论了两体随机系综相互作用多体系统的基态角动量分布。从几个简单的例子出发，提出了一种计算P（I），角动量I基态（g. s.）概率，一些可解的情况下，如费米子在一个小的单j壳和d玻色子系统，给出。这种方法可以推广到更复杂的情况，如大的单j壳层或多j壳层中的费米子个数为偶数或奇数，d-玻色子、sd-玻色子或sdg-玻色子系统等。通过这种方法，我们可以知道在多体系统中哪些相互作用是产生相当大的P（I）所必需的。G. S。讨论了最大角动量$I_{max}$的概率。我们的方法的微观基础上的一个参数，和某些矩阵元素，这是有用的，以了解所观察到的，也给出或详细说明。低年资的0克。通过使用相同的一组两体相互作用，得到了证实，但注意到对总0 g. s.对于单j壳层中的费米子来说，超出该链的概率可能更重要。初步结果采取位移两体随机合奏的I g. s。概率
Eigenvalues correlations and the distribution of ground state angular momenta for random many-body quantum systems
本文用本征态之间的相关系数（协方差）分析了在具有随机两体相互作用的多体量子系统中，角动量L=0的基态的优势.结果表明，Chau { \it et al.}可以用能量本征值之间的相关性（协方差）来解释，从而提供了随机相互作用量子系统的基态角动量分布的完全统计解释，这在原则上对费米子和玻色子系统都有效。该方法的相互作用玻色子模型示出。
Astrophysical observations of neutron stars have been widely used to infer the properties of the nuclear matter equation of state. Beside being a source of information on average properties of dense matter, however, the data provided by electromagnetic and gravitational wave (GW) facilities are reaching the accuracy needed to constrain, for the first time, nuclear dynamics in dense matter. In this work we assess the sensitivity of current and future neutron star observations to directly infer the strength of repulsive three-nucleon forces, which are key to determine the stiffness of the equati…
Time-Dependent Density Functional Theory is mathematically formulated through non-linear coupled time-dependent 3-dimensional partial differential equations and it is natural to expect a strong sensitivity of its solutions to variations of the initial conditions, akin to the butterfly effect ubiquitous in classical dynamics. Since the Schrödinger equation for an interacting many-body system is however linear and mathematically the exact equations of the Density Functional Theory reproduce the corresponding one-body properties, it would follow that the Lyapunov exponents are also vanishing with…
