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Related papers: Coupled cluster theory: Towards an algebraic geome…

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The formation of clusters in nuclear matter is investigated, which occurs e.g. in low energy heavy ion collisions or core-collapse supernovae. In astrophysical applications, the excluded volume concept is commonly used for the description…

Nuclear Theory · Physics 2011-11-24 Matthias Hempel , Jürgen Schaffner-Bielich , Stefan Typel , Gerd Röpke

We extend recent algebro-geometric results for coupled cluster theory of quantum many-body systems to the truncation varieties arising from the doubles approximation (CCD), focusing on the first genuinely nonlinear doubles regime of four…

Algebraic Geometry · Mathematics 2026-02-19 Fabian M. Faulstich , Vincenzo Galgano , Elke Neuhaus , Irem Portakal

In electronic structure theory, restricted single-reference coupled cluster (CC) captures weak correlation but fails catastrophically under strong correlation. Spin-projected unrestricted Hartree-Fock (SUHF), on the other hand, misses weak…

Chemical Physics · Physics 2017-11-22 John A. Gomez , Thomas M. Henderson , Gustavo E. Scuseria

We propose an approach to approximately implement the variational coupled cluster (VCC) theory on quantum computers, which struggles with exponential scaling of computational costs on classical computers. To this end, we employ expanding…

Quantum Physics · Physics 2024-06-12 Luca Erhart , Yuichiro Yoshida , Viktor Khinevich , Wataru Mizukami

This paper proposes a new paradigm and computational framework for identification of correspondences between sub-structures of distinct composite systems. For this, we define and investigate a variant of traditional data clustering, termed…

Machine Learning · Computer Science 2007-05-23 Zvika Marx , Ido Dagan , Joachim Buhmann

The classical Kepler-Coulomb system in 3 dimensions is well known to be 2nd order superintegrable, with a symmetry algebra that closes polynomially under Poisson brackets. This polynomial closure is typical for 2nd order superintegrable…

Mathematical Physics · Physics 2012-06-08 Ernie G. Kalnins Kalnins , Willard Miller

This paper develops a geometric model for coupled two-state quantum systems (qubits), which is formulated using geometric (aka Clifford) algebra. It begins by showing how Euclidean spinors can be interpreted as entities in the geometric…

Quantum Physics · Physics 2007-05-23 Timothy F. Havel , Chris J. L. Doran

Cluster algebras are a recent topic of study and have been shown to be a useful tool to characterize structures in several knowledge fields. An important problem is to establish whether or not a given cluster algebra is of finite type.…

Commutative Algebra · Mathematics 2015-07-15 Elisângela Silva Dias , Diane Castonguay

Recently developed pair coupled cluster doubles (pCCD) theory successfully reproduces doubly occupied configuration interaction (DOCI) with mean field cost. However, the projective nature of pCCD makes the method non-variational and thus…

Chemical Physics · Physics 2016-08-19 Luning Zhao , Eric Neuscamman

We review how the (quantum) cluster algebra naturally emerges in the study of four-dimensional $\mathcal{N}=2$ supersymmetric gauge theories.

High Energy Physics - Theory · Physics 2017-05-25 Masahito Yamazaki

This paper studies the statistical and computational limits of high-order clustering with planted structures. We focus on two clustering models, constant high-order clustering (CHC) and rank-one higher-order clustering (ROHC), and study the…

Statistics Theory · Mathematics 2023-10-04 Yuetian Luo , Anru R. Zhang

The formulation of the time-dependent Schrodinger equation in terms of coupled-cluster theory is outlined, with emphasis on the bivariational framework and its classical Hamiltonian structure. An indefinite inner product is introduced,…

Chemical Physics · Physics 2019-04-16 Thomas Bondo Pedersen , Simen Kvaal

The cluster analysis of very large objects is an important problem, which spans several theoretical as well as applied branches of mathematics and computer science. Here we suggest a novel approach: under assumption of local convergence of…

Combinatorics · Mathematics 2015-10-28 Jaroslav Nesetril , Patrice Ossona de Mendez

An implementation of coupled-cluster (CC) theory to treat atoms and molecules in finite magnetic fields is presented. The main challenges stem from the magnetic-field dependence in the Hamiltonian, or, more precisely, the appearance of the…

Chemical Physics · Physics 2015-09-02 Stella Stopkowicz , Jürgen Gauss , Kai K. Lange , Erik I. Tellgren , Trygve Helgaker

Computational complexity is a new quantum information concept that may play an important role in holography and in understanding the physics of the black hole interior. We consider quantum computational complexity for $n$ qubits using…

High Energy Physics - Theory · Physics 2021-05-21 Roberto Auzzi , Stefano Baiguera , G. Bruno De Luca , Andrea Legramandi , Giuseppe Nardelli , Nicolò Zenoni

The tailored coupled cluster (TCC) approach is a promising ansatz that preserves the simplicity of single-reference coupled cluster theory, while incorporating a multi-reference wave function through amplitudes obtained from a preceding…

Chemical Physics · Physics 2021-01-07 Maximilian Mörchen , Leon Freitag , Markus Reiher

In the present paper we examine the relationship between several type $A$ cluster theories and structures. We define a 2D geometric model of a cluster theory, which generalizes cluster algebras from surfaces, and encode several existing…

Representation Theory · Mathematics 2022-01-03 Job Daisie Rock

The recent quantum information boom has effected a resurgence of interest in unitary coupled cluster (UCC) theory. Our group's interest in local energy landscapes of unitary ans\"atze prompted us to investigate the classical approach of…

Chemical Physics · Physics 2022-11-01 Harper R. Grimsley , Nicholas J. Mayhall

We develop a coupled-cluster theory for bosonic mixtures of binary species in external traps, providing a promising theoretical approach to demonstrate highly accurately the many-body physics of mixtures of Bose-Einstein condensates. The…

Quantum Gases · Physics 2024-02-01 Anal Bhowmik , Ofir E. Alon

We use, for the first time, ab initio coupled-cluster theory to compute the spectral function of the uniform electron gas at a Wigner-Seitz radius of $r_\mathrm{s}=4$. The coupled-cluster approximations we employ go significantly beyond the…