7,773 research outputs found
Use tax collections
The article reports on a study which investigated the level of compliance with U.S. state use tax laws and the techniques employed by the states in order to enforce use tax. Most states utilize either of two forms of tax reporting and collection. These are: the introduction of a separate use tax form/return; or the use of a separate line on the state income tax return. It was observed that utilizing a separate line item on the state income tax return might cause a rise in the number of taxpayers
Statistical lossless compression of space imagery and general data in a reconfigurable architecture
Spin-wave amplification and lasing driven by inhomogeneous spin transfer torques
We show that an inhomogeneity in the spin-transfer torques in a metallic
ferromagnet under suitable conditions strongly amplifies incoming spin waves.
Moreover, at nonzero temperatures the incoming thermally occupied spin waves
will be amplified such that the region with inhomogeneous spin transfer torques
emits spin waves spontaneously, thus constituting a spin-wave laser. We
determine the spin-wave scattering amplitudes for a simplified model and
set-up, and show under which conditions the amplification and lasing occurs.
Our results are interpreted in terms of a so-called black-hole laser, and could
facilitate the field of magnonics, that aims to utilize spin waves in logic and
data-processing devices.Comment: 5 pages, 4 figure
Solution to the Isotropy Problem for Cosmological Hidden Vector Models
Gauge bosons associated to new gauge symmetries under which the standard
model particles are not charged are predicted in many extensions of the
standard model of particles and interactions. We show that under very general
conditions, the average energy-momentum tensor of these rapidly oscillating
vector fields is isotropic for any locally inertial observer. This result has a
fundamental importance in order to consider coherent vector fields as a viable
alternative to support models of dark matter, dark energy or inflation.Comment: 4 pages, 1 figure. Contributed to the 9th Patras Workshop on Axions,
WIMPs and WISPs, Mainz, June 24-28, 201
Black hole - D-brane correspondence: An example
We explore the connection between D-branes and black holes in one particular
case: a -brane compactified to four dimensions on . Using the
-brane boundary state description we show the equivalence with a double
extremal N=2 black hole solution of four dimensional supergravity.Comment: 15 pages, LaTeX. Contribution by C. Nunez to the conference Quantum
Gravity in the Southern Cone, Bariloche 7-10 January 1998; to appear in the
proceeding
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