The many-body theory of degenerate systems is described in detail. More generally, this theory applies to systems with an initial state that cannot be described by a single Slater determinant. The double-source (or closed-time-path) formalism of nonequilibrium quantum field theory is used to derive an expression for the average value of a product of interacting fields when the initial state is ...

A quantum Monte Carlo study of the atomization energies for the G2 set of molecules is presented. Basis size dependence of diffusion Monte Carlo atomization energies is studied with a single determinant Slater-Jastrow trial wavefunction formed from Hartree-Fock orbitals. With the largest basis set, the mean absolute deviation from experimental atomization energies for the G2 set is 3.0 kcal/mol...

A quantum Monte Carlo study of the atomization energies for the G2 set of molecules is presented. Basis size dependence of diffusion Monte Carlo atomization energies is studied with a single determinant Slater-Jastrow trial wavefunction formed from Hartree-Fock orbitals. With the largest basis set, the mean absolute deviation from experimental atomization energies for the G2 set is 3.0 kcal/mol...

The total variation T V (u) of the Jacobian determinant of non-smooth vector fields u has recently been studied in [2]. We focus on the subclass u(x) = ϕ(x/|x|) of homogeneous extensions of smooth functions ϕ : ∂B n → R n. In the case n = 2, we explicitely compute T V (u) for some relevant examples exhibiting a gap with respect to the total variation |DetDu| of the distributional determinant. W...

When running time-dependent density functional theory (TDDFT) calculations for real-time simulations of non-equilibrium dynamics, the user has a choice of initial Kohn-Sham state, and typically a Slater determinant is used. We explore the impact of this choice on the exchange-correlation potential when the physical system begins in a 50 : 50 superposition of the ground and first-excited state o...

We present results for the phase diagram of three flavor QCD for μB<∼500 MeV. Our simulations are performed with imaginary chemical potential μI for which the fermion determinant is positive. Physical observables are then fitted by truncated Taylor series and continued to real chemical potential. We map out the location of the critical line Tc(μB) with an accuracy up to terms of order (μB/T ) 6...

Fermion propagator is computed in a simple model on an extremely anisotropic lattice ξ ≫ 1. Fermion determinant is evaluated up to ξ−4 order. Chiral condensate is estimated in mean field approximation.

Wendt's binomial circulant determinant, W„ , is the determinant of an m by m circulant matrix of integers, with {i, ;')th entry (i,TM.i) whenever 2 divides m but 3 does not. We explain how we found the prime factors of Wm for each even m < 200 by implementing a new method for computations in algebraic number fields that uses only modular arithmetic. As a consequence we prove that if p and q = m...