14,275 research outputs found
Quasi-sparse eigenvector diagonalization and stochastic error correction
We briefly review the diagonalization of quantum Hamiltonians using the
quasi-sparse eigenvector (QSE) method. We also introduce the technique of
stochastic error correction, which systematically removes the truncation error
of the QSE result by stochastically sampling the contribution of the remaining
basis states.Comment: 5 pages, to appear in the proceedings of the International Light-Cone
Meeting on Non-Perturbative QCD and Hadron Phenomenology, Heidelberg, June
200
Lattice simulations for few- and many-body systems
We review the recent literature on lattice simulations for few- and many-body
systems. We focus on methods and results that combine the framework of
effective field theory with computational lattice methods. Lattice effective
field theory is discussed for cold atoms as well as low-energy nucleons with
and without pions. A number of different lattice formulations and computational
algorithms are considered, and an effort is made to show common themes in
studies of cold atoms and low-energy nuclear physics as well as common themes
in work by different collaborations.Comment: 71 pages, 20 figures, published version to appear in Progress in
Particle and Nuclear Physic
Ground state energy of spin-1/2 fermions in the unitary limit
We present lattice results for the ground state energy of a spin-1/2 fermion
system in the unitary limit, where the effective range of the interaction is
zero and the scattering length is infinite. We compute the ground state energy
for a system of 6, 10, 14, 18, and 22 particles, with equal numbers of up and
down spins in a periodic cube. We estimate that in the limit of large number of
particles, the ground state energy is 0.25(3) times the ground state energy of
the free Fermi system.Comment: 17 pages, 9 figures, expanded manuscript includes more data and
cross-check
Spherical gauge fields
We introduce the spherical field formalism for free gauge fields. We discuss
the structure of the spherical Hamiltonian for both general covariant gauge and
radial gauge and point out several new features not present in the scalar field
case. We then use the evolution equations to compute gauge-field and
field-strength correlators
Large-N droplets in two dimensions
Using lattice effective field theory, we study the ground state binding
energy of N distinct particles in two dimensions with equal mass interacting
weakly via an attractive SU(N)-symmetric short range potential. We find that in
the limit of zero range and large N, the ratio of binding energies
B_{N}/B_{N-1} approaches the value 8.3(6).Comment: 18 pages, 6 figures, version to appear in Phys. Rev.
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