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We consider the problem of clustering a set of high-dimensional data points into sets of low-dimensional linear subspaces. The number of subspaces, their dimensions, and their orientations are unknown. We propose a simple and low-complexity…

Information Theory · Computer Science 2013-03-18 Reinhard Heckel , Helmut Bölcskei

I report on an implementation of an algorithm for the automated numerical calculation of spin- and colour-correlated Born matrix elements in QCD. These spin- and colour-correlated matrix elements are needed for NLO calculations in…

High Energy Physics - Phenomenology · Physics 2009-01-07 Stefan Weinzierl

Single-reference coupled-cluster theory is an accurate and affordable computational method for the nuclear many-body problem. For open-shell nuclei, the reference state typically breaks rotational invariance and angular momentum must be…

Nuclear Theory · Physics 2022-08-03 G. Hagen , S. J. Novario , Z. H. Sun , T. Papenbrock , G. R. Jansen , J. G. Lietz , T. Duguet , A. Tichai

Spectral clustering is a popular algorithm that clusters points using the eigenvalues and eigenvectors of Laplacian matrices derived from the data. For years, spectral clustering has been working mysteriously. This paper explains spectral…

Machine Learning · Statistics 2021-03-02 T Shen

We propose a method for microscopic calculations of nuclear ground-state properties in the framework of density functional theory. We discuss how the density functional is equivalent to the effective action for the density, thereby…

Nuclear Theory · Physics 2007-05-23 A. Schwenk , J. Polonyi

Double--folded optical $\alpha$--nucleus potentials can be used to calculate elastic scattering cross sections in a wide mass-- and energy region. Because of the systematic behavior of the potential parameters we are able to obtain reliable…

Nuclear Theory · Physics 2009-09-25 P. Mohr , H. Abele , U. Atzrott , G. Staudt , R. Bieber , K. Grün , H. Oberhummer , T. Rauscher , E. Somorjai

Mixing single and triple fermions an exact killing operator of the Coupled Cluster Doubles (CCD) wave function with good symmetry was found in \cite{Tohy13}. Using these operators with the equation of motion (EOM) method the so-called…

Nuclear Theory · Physics 2020-10-26 Mohsen Jemaï , Peter Schuck

We have developed an efficient scheme for the calculation of transition properties within the four-component relativistic equation-of-motion coupled-cluster (EOM-CC) method using the expectation value approach. The calculation of transition…

In this work, we use modern electronic structure methods to model the catalytic mechanism of different variants of the molybdenum cofactor (Moco). We investigate the dependence of various Moco model systems on structural relaxation and the…

Exploring nuclear physics through the fundamental constituents of the strong force -- quarks and gluons -- is a formidable challenge. While numerical calculations using lattice quantum chromodynamics offer the most promising approach for…

High Energy Physics - Lattice · Physics 2024-12-19 Debsubhra Chakraborty , Piyush Srivastava , Arpith Kumar , Nilmani Mathur

The method of QCD sum rules has proven to be particularly useful in heavy quark physics, where a small distance scale is provided by the inverse heavy quark mass. We present two new examples for the application of this method to B-physics:…

High Energy Physics - Phenomenology · Physics 2009-09-25 A. Khodjamirian , R. Rückl

The magnetic dipole and electric quadrupole hyperfine constants of Aluminium ($^{27}Al$) atom are computed using the relativistic coupled cluster (CC) and unitary coupled cluster (UCC) methods. Effects of electron correlations are…

Atomic Physics · Physics 2007-05-23 Chiranjib Sur , Rajat K. Chaudhuri , B. P. Das , D. Mukherjee

Using the relationship between the two-particle overlap functions (TOF's) and the two-body density matrix (TDM), the TOF's for $^{16}$O$(e,e^{\prime}pp)^{14}$C reaction are calculated on the basis of TDM obtained with a Jastrow-type…

Nuclear Theory · Physics 2007-05-23 D. N. Kadrev , M. V. Ivanov , A. N. Antonov , C. Giusti , F. D. Pacati

We compute inclusive electron-nucleus cross sections using ab initio spectral functions of $^4$He and $^{16}$O obtained within the Self Consistent Green's Function approach. The formalism adopted is based on the factorization of the…

Nuclear Theory · Physics 2018-08-15 N. Rocco , C. Barbieri

In a series of two articles, we propose a comprehensive mathematical framework for Coupled-Cluster-type methods. In this second part, we analyze the nonlinear equations of the single-reference Coupled-Cluster method using topological degree…

Numerical Analysis · Mathematics 2023-03-28 Mihály A. Csirik , Andre Laestadius

Microscopic calculations of neutrino-nucleus scattering cross sections are critical for the success of the neutrino-oscillation program. In addition to retaining nuclear correlations in the initial and final state of the reaction, they are…

Nuclear Theory · Physics 2023-04-25 Alexis Nikolakopoulos , Alessandro Lovato , Noemi Rocco

An electrodynamical coupled cluster (CC) methodology starting from a covariant formalism and an equal time approximation, and finally based on the Dirac-Fock picture of the electron and positron fields and Coulomb gauge, is given here. The…

Atomic Physics · Physics 2019-04-30 Sambhu N. Datta

We present an algorithm for the numerical calculation of one-loop QCD amplitudes. The algorithm consists of subtraction terms, approximating the soft, collinear and ultraviolet divergences of one-loop amplitudes and a method to deform the…

High Energy Physics - Phenomenology · Physics 2010-12-09 Sebastian Becker , Christian Reuschle , Stefan Weinzierl

We study the nucleon-nucleon interaction in a chiral constituent quark model by using the resonating group method, convenient for treating the interaction between composite particles. The calculated phase shifts for the 3S1 and 1S0 channels…

Nuclear Theory · Physics 2009-11-06 D. Bartz , Fl. Stancu

The detection and parametrization of molecular clumps is the first step in studying them. We propose a method based on Local Density Clustering algorithm while physical parameters of those clumps are measured using the Multiple Gaussian…

Instrumentation and Methods for Astrophysics · Physics 2022-02-02 Xiaoyu Luo , Sheng Zheng , Yao Huang , Shuguang Zeng , Xiangyun Zeng , Zhibo Jiang , Zhiwei Chen