199,371 research outputs found
On the hydrostatic approximation of the Navier-Stokes equations in a thin strip
In this paper, we first prove the global well-posedness of a scaled
anisotropic Navier-Stokes system and the hydrostatic Navier-Stokes system in a
2-D striped domain with small analytic data in the tangential variable. Then we
justify the limit from the anisotropic Navier-Stokes system to the hydrostatic
Navier-Stokes system with analytic data
Resonant Tunneling through S- and U-shaped Graphene Nanoribbons
We theoretically investigate resonant tunneling through S- and U-shaped
nanostructured graphene nanoribbons. A rich structure of resonant tunneling
peaks are found eminating from different quasi-bound states in the middle
region. The tunneling current can be turned on and off by varying the Fermi
energy. Tunability of resonant tunneling is realized by changing the width of
the left and/or right leads and without the use of any external gates.Comment: 6 pages, 7 figure
Unitarity and Complete Reducibility of Certain Modules over Quantized Affine Lie Algebras
Let denote the quantized affine Lie algebra and
the quantized {\em nontwisted} affine Lie algebra. Let
be the category defined in section 3. We show that when
the deformation parameter is not a root of unit all integrable
representations of in the category are
completely reducible and that every integrable irreducible highest weight
module over corresponding to is equivalent to a
unitary module.Comment: 17 pages (minor errors corrected
Tunnelling Effect and Hawking Radiation from a Vaidya Black Hole
In this paper, we extend Parikh' work to the non-stationary black hole. As an
example of the non-stationary black hole, we study the tunnelling effect and
Hawking radiation from a Vaidya black hole whose Bondi mass is identical to its
mass parameter. We view Hawking radiation as a tunnelling process across the
event horizon and calculate the tunnelling probability. We find that the result
is different from Parikh's work because is the function of
Bondi mass m(v)
Experimental Implications for a Linear Collider of the SUSY Dark Matter Scenario
This paper presents the detection issues for the lightest slepton
\tilde{\tau}_1 at a future e^+e^- TeV collider given the dark matter
constraints set on the SUSY mass spectrum by the WMAP results. It intends to
illustrate the importance of an optimal detection of energetic electrons in the
very forward region for an efficient rejection of the
\gamma\gamma background. The TESLA parameters have been used in the case of
head-on collisions and in the case of a 10, mrad half crossing angle.Comment: 24 pages, 13 figures, Work presented at the International Conference
on Linear Colliders (LCWS04), 19-23 April 2004, Le Carre des Sciences, Paris,
Franc
Detuning effects in the one-photon mazer
The quantum theory of the mazer in the non-resonant case (a detuning between
the cavity mode and the atomic transition frequencies is present) is written.
The generalization from the resonant case is far from being direct. Interesting
effects of the mazer physics are pointed out. In particular, it is shown that
the cavity may slow down or speed up the atoms according to the sign of the
detuning and that the induced emission process may be completely blocked by use
of a positive detuning. It is also shown that the detuning adds a potential
step effect not present at resonance and that the use of positive detunings
defines a well-controlled cooling mechanism. In the special case of a mesa
cavity mode function, generalized expressions for the reflection and
transmission coefficients have been obtained. The general properties of the
induced emission probability are finally discussed in the hot, intermediate and
cold atom regimes. Comparison with the resonant case is given.Comment: 9 pages, 8 figure
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