We revisit the problem of interacting electrons hopping on a two-leg ladder. A perturbative renormalizationgroup analysis reveals that at half-filling the model scales onto an exactly soluble Gross-Neveu model for arbitrary finite-ranged interactions, provided they are sufficiently weak. The Gross-Neveu model has an enormous global SO~8! symmetry, manifest in terms of eight real Fermion fields ...

Very low energy diets have been used clinically as an aid to weight loss in gross obesity.' The recent more general availability ofsuch diets has enabled them to be used without medical supervision by people with moderate to minimal obesity. The present case illustrates an interesting though rare manifestation of very low energy intake; indeed, low energy, low carbohydrate diets were advocated ...

Animals may forage using different currencies depending on whether time minimization or energy maximization is more pertinent at the time. Assessment of net energy acquisition requires detailed information on instantaneous activity-specific power use, which varies according to animal performance, being influenced, for example, by speed and prey loading, and which has not been measured before in...

Recently, we have addressed the e€ects of overall shape upon the electronic response of isolated molecules and nanoclusters, with particular emphasis on the mean excitation energy. Here, we consider the relationship between gross molecular shape and mean excitation energy anisotropy for very long objects. In particular we compare results for elongated ellipsoids and a string of particles. We ®n...

For the nonlocal T-periodic Gross–Pitaevsky operator, formal solutions of the Floquet problem asymptotic in small parameter , → 0, up to O(3/2) have been constructed. The quasi-energy spectral series found correspond to the closed phase trajectories of the Hamilton–Ehrenfest system which are stable in the linear approximation. The monodromy operator of this equation has been constructed to with...

The macroscopic quantum states of a condensed neutral Bose gas in one-dimensional power-law traps are obtained by solving the Gross-Pitaevskii equation numerically. A suitable candidate for a trial wave function for the variational calculation of the ground-state energy is suggested. It is shown that the suggested function exp(−r), where k is the power of the trap, produces a lower ground-state...