3,598 research outputs found
Finite Lattice Hamiltonian Computations in the P-Representation: the Schwinger Model
The Schwinger model is studied in a finite lattice by means of the
P-representation. The vacuum energy, mass gap and chiral condensate are
evaluated showing good agreement with the expected values in the continuum
limit.Comment: 6 pages, 5 eps figures, espcrc
Multibranch Bogoliubov-Bloch spectrum of a cigar shaped Bose condensate in an optical lattice
We study properties of excited states of an array of weakly coupled
quasi-two-dimensional Bose condensates by using the hydrodynamic theory. The
spectrum of the axial excited states strongly depends on the coupling among the
various discrete radial modes in a given symmetry. By including mode-coupling
within a given symmetry, the complete excitation spectrum of axial
quasiparticles with various discrete radial nodes are presented. A single
parameter which determines the strength of the mode coupling is identified. The
excitation spectrum in the zero angular momentum sector can be observed by
using the Bragg scattering experiments.Comment: to apper in Phys. Rev.
More Schooling, More Children: Compulsory Schooling Reforms and Fertility in Europe
We study the relationship between education and fertility, exploiting compulsory schooling reforms in Europe as source of exogenous variation in education. Using data from 8 European countries, we assess the causal effect of education on the number of biological kids and the incidence of childlessness. We find that more education causes a substantial decrease in childlessness and an increase in the average number of children per woman. Our findings are robust to a number of falsification checks and we can provide complementary empirical evidence on the mechanisms leading to these surprising results.
- …