33,907 research outputs found
Density Functional Theory Studies of Magnetically Confined Fermi Gas
A theory is developed for magnetically confined Fermi gas at low temperature
based on the density functional theory. The theory is illustrated by numerical
calculation of density distributions of Fermi atoms K with parameters
according to DeMarco and Jin's experiment[Science, 285(1999)1703]. Our results
are in good agreement with the experiment. To check the theory, we also
performed calculations using our theory at high temperature and compared very
well to the result of classical limit.Comment: 6 page
Andreev Bound states in One Dimensional Topological Superconductor
We study the charge character of the Andreev bound states (ABSs) in
one-dimensional topological superconductors with spatial inversion symmetry
(SIS) breaking. Despite the absence of the SIS, we show a hidden symmetry for
the Bogoliubov de Gennes equations around Fermi points in addition to the
particle-hole symmetry. This hidden symmetry protects that the charge of the
ABSs is solely dependent on the corresponding Fermi velocities. On the other
hand, if the SIS is present, the ABSs are charge neutral, similar to Majorana
fermions. We demonstrate that the charge of the ABSs can be experimentally
measured in the tunneling transport spectroscopy from the resonant differential
tunneling conductance.Comment: 4 pages plus appendix; 4 figure
Competition, Innovation and Racing for Priority at the U.S. Patent and Trademark Office
The U.S. Patent and Trademark Office resolves patent priority disputes in patent interference cases. Using a random sample of cases declared between 1988 and 1994, we establish a connection between patent interferences and patent races, and then use the data to consider some key issues in dynamic competition and innovation. We look at the incidence and distribution of patent races by technology, evidence for strategic delay of innovation by incumbent firms, and evidence that patent races moderate incentives to delay. Our results have implications for patent policy in general and for evaluating the U.S. “first to invent†patent priority rule.Patent race, Patent interference, US Board of Patent Appeals and Interferences, Patent litigation; Innovation; Research and development
Valid Inference for a Class of Models Where Standard Inference Performs Poorly: Including Nonlinear Regression, ARMA, GARCH, and Unobserved Components
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