1,355 research outputs found
Excessive Salaries in a Closely Held Corporation
Excessive salaries paid by a closely held corporation create a constant debate between the owners of the entity and the Internal Revenue Service, and with other corporation members. The basic law as to the tax aspects underlying the controversy, in the Internal Revenue Code of 1954, is substantially as follows: The compensation claimed as a deduction must be reasonable in amount, and must be paid purely for services. Distributions of profits under the guise of salaries are not deductible. This crucial issue leads to the question: What does the word reasonable salary mean in the framework of a closely held corporation
Fermionization of two-component few-fermion systems in a one-dimensional harmonic trap
The nature of strongly interacting Fermi gases and magnetism is one of the
most important and studied topics in condensed-matter physics. Still, there are
many open questions. A central issue is under what circumstances strong
short-range repulsive interactions are enough to drive magnetic correlations.
Recent progress in the field of cold atomic gases allows to address this
question in very clean systems where both particle numbers, interactions and
dimensionality can be tuned. Here we study fermionic few-body systems in a one
dimensional harmonic trap using a new rapidly converging effective-interaction
technique, plus a novel analytical approach. This allows us to calculate the
properties of a single spin-down atom interacting with a number of spin-up
particles, a case of much recent experimental interest. Our findings indicate
that, in the strongly interacting limit, spin-up and spin-down particles want
to separate in the trap, which we interpret as a microscopic precursor of
one-dimensional ferromagnetism in imbalanced systems. Our predictions are
directly addressable in current experiments on ultracold atomic few-body
systems.Comment: 12 pages, 6 figures, published version including two appendices on
our new numerical and analytical approac
Bound States and Universality in Layers of Cold Polar Molecules
The recent experimental realization of cold polar molecules in the rotational
and vibrational ground state opens the door to the study of a wealth of
phenomena involving long-range interactions. By applying an optical lattice to
a gas of cold polar molecules one can create a layered system of planar traps.
Due to the long-range dipole-dipole interaction one expects a rich structure of
bound complexes in this geometry. We study the bilayer case and determine the
two-body bound state properties as a function of the interaction strength. The
results clearly show that a least one bound state will always be present in the
system. In addition, bound states at zero energy show universal behavior and
extend to very large radii. These results suggest that non-trivial bound
complexes of more than two particles are likely in the bilayer and in more
complicated chain structures in multi-layer systems.Comment: 6 pages, 5 figures. Revised version to be publishe
Shell-Model Monte Carlo Simulations of BCS-BEC Crossover in Few-Fermion Systems
We study a trapped system of fermions with a zero-range two-body interaction
using the shell-model Monte Carlo method, providing {\em ab initio} results for
the low particle number limit where mean-field theory is not applicable. We
present results for the -body energies as function of interaction strength,
particle number, and temperature. The subtle question of renormalization in a
finite model space is addressed and the convergence of our method and its
applicability across the BCS-BEC crossover is discussed. Our findings indicate
that very good quantitative results can be obtained on the BCS side, whereas at
unitarity and in the BEC regime the convergence is less clear. Comparison to
N=2 analytics at zero and finite temperature, and to other calculations in the
literature for show very good agreement.Comment: 6 pages, 5 figures, Revtex4, final versio
- …