Related papers: Coupled-cluster theory for three-body Hamiltonians
The goal of the present account is to review our efforts to obtain and apply a ``collective'' Hamiltonian for a few, approximately decoupled, adiabatic degrees of freedom, starting from a Hamiltonian system with more or many more degrees of…
The three main contributions to the nuclear Hamiltonian - monopole, quadrupole and pairing - are analyzed in a shell model context. The first has to be treated phenomenologically, while the other two can be reliably extracted from the…
In the effort to design and to construct a quantum computer, several leading proposals make use of spin-based qubits. These designs generally assume that spins undergo pairwise interactions. We point out that, when several spins are engaged…
We discuss the description of a many-body nuclear system using Hamiltonians that contain the nucleon relativistic kinetic energy and potentials with relativistic corrections. Through the Foldy-Wouthuysen transformation, the field…
Coupled-cluster theory is a powerful tool for first-principles calculations of atomic nuclei, enabling accurate predictions of nuclear observables across the Segr\`e chart. While coupled-cluster computations are especially efficient at…
A series of accurate ab initio calculations on Cu_pO-q finite clusters, properly embedded on the Madelung potential of the infinite lattice, have been performed in order to determine the local effective interactions in the CuO_2 planes of…
A detailed comparison of Faddeev and variational wave functions for $^3$H, calculated with realistic nuclear forces, has been made to study the form of three-body correlations in few-body nuclei. Three new three-body correlations for use in…
We compute the energy per particle of infinite symmetric nuclear matter from chiral N3LO (next-to-next-to-next-to-leading order) two-body potentials plus N2LO three-body forces. The low-energy constants of the chiral three-nucleon force…
Here we study the effects of many-body interactions on rate and mechanism in protein folding, using the results of molecular dynamics simulations on numerous coarse-grained C-alpha-model single-domain proteins. After adding three-body…
Modern softened nucleon-nucleon interactions are well-suited for perturbative many-body calculations, but a many-body power counting scheme is lacking. Estimates of diagrammatic contributions at finite density are important ingredients in…
Energy levels of the double-$\Lambda$ hypernuclei $_\Lambda^{}$$_\Lambda^7$He, $_\Lambda^{}$$_\Lambda^7$Li, $_\Lambda^{}$$_\Lambda^8$Li, $_\Lambda^{}$$_\Lambda^9$Li, $_\Lambda^{}$$_\Lambda^9$Be and $_\Lambda^{}$$_\Lambda^{10}$Be are…
We study three-body systems composed of $D^{(*)}$, $B^{(*)}$ and $\bar{B}^{(*)}$ in order to look for possible bound states or resonances. In order to solve the three-body problem, we use the fixed center approach for the Faddeev equations…
The three body (triple dipole) interaction of Axilrod, Teller and Muto (ATM) contributes 5 to 10 % of the total energy of condensed phases of inert elements. It is shown in this paper for clusters and films that a much larger or smaller ATM…
Gravitational and electromagnetic interactions are Hamiltonian systems with forces between pairs of particles. We propose an alternative: Hamiltonian dynamics with triplet interactions between point particles. Our system has a potential…
We present a natural orbital-based implementation of the intermediate Hamiltonian Fock space coupled-cluster method for (1,1) sector of Fock space. The use of natural orbital significantly reduces the computational cost and can…
We propose a general strategy to develop quantum many-body approximations of primitives in linear algebra algorithms. As a practical example, we introduce a coupled-cluster inspired framework to produce approximate Hamiltonian moments, and…
We derive the coupled-cluster doubles (CCD) amplitude equations by introduction of the particle-hole-time decoupled electronic self-energy. The resulting analysis leads to an expression for the ground state correlation energy that is…
We present a full study of the 3-body problem in gravity in flat (2+1)-dimensional space-time, and in the nonrelativistic limit of small velocities. We provide an explicit form of the ADM Hamiltonian in a regular coordinate system and we…
The challenging nuclear many-body problem is discussed along with classifications and qualitative descriptions of existing methods and models. We present detailed derivations of a new method where cluster correlations co-exist with an…
In this work we investigate small clusters of helium atoms using the hyperspherical harmonic basis. We consider systems with $A=2,3,4,5,6$ atoms with an inter-particle potential which does not present a strong repulsion at short distances.…