712 research outputs found
Fano versus Kondo Resonances in a Multilevel "Semi-Open" Quantum Dot
Linear conductance across a large quantum dot via a single level e_0 with
large hybridization to the contacts is strongly sensitive to quasi-bound states
localized in the dot and weakly coupled to e_0. It oscillates with the gate
voltage due to interference of the Fano type. At low temperature and Coulomb
blockade, Kondo correlations damp the oscillations on an extended range of gate
voltage values, by freezing the occupancy of the e_0 level itself. As a
consequence, antiresonances of Fano origin are washed out. The results are in
good correspondence with experimental data for a large quantum dot in the
semi-open regime.Comment: 4 eps figures, RevTex format, revised version, to appear in Phys.
Rev. Letter
On Type IIA geometries dual to N = 2 SCFTs
We provide explicit solutions of Type IIA supergravity which are believed to
be dual to N = 2 superconformal four dimensional gauge theories. These explicit
solutions are based on the general ansatz for such a type of backgrounds
introduced by Gaiotto and Maldacena.Comment: 23 pages, 10 figures; minor corrections, references correcte
Open Semiclassical Strings and Long Defect Operators in AdS/dCFT Correspondence
We consider defect composite operators in a defect superconformal field
theory obtained by inserting an AdS_4 x S^2-brane in the AdS_5 x S^5
background. The one-loop dilatation operator for the scalar sector is
represented by an integrable open spin chain. We give a description to
construct coherent states for the open spin chain. Then, by evaluating the
expectation value of the Hamiltonian with the coherent states in a long
operator limit, a Landau-Lifshitz type of sigma model action is obtained. This
action is also derived from the string action and hence we find a complete
agreement in both SYM and string sides. We see that an SO(3)_H pulsating string
solution is included in the action and its energy completely agrees with the
result calculated in a different method. In addition, we argue that our
procedure would be applicable to other AdS-brane cases.Comment: 22 pages, 1 figure, LaTeX, minor corrections and references added.
v3) some new results added. shortened and accepted version in PR
A standardized and modular power electronics platform for academic research on advanced grid-connected converter control and microgrids
This paper introduces a multifunctional converter platform rated at 30kW. Individual units allow research on advanced grid-connected converter control, while their interconnection enables isolated microgrid investigations. The standardized and modular design allows simple reconfiguration of the system for different setups, for which multiple measurements are presented
Causal effects of PetroCaribe on sustainable development: a synthetic control analysis
We examine the causal effects of the energy subsidy programme PetroCaribe in the three dimensions of sustainable development: economic, social and environmental. We use the synthetic control method to construct a counterfactual and compare it to the outcomes of the beneficiary countries and thus estimate the magnitude and direction of the PetroCaribe effect. PetroCaribe had a positive effect on economic growth in most of the beneficiary countries; however, this economic boost was not followed by an improvement in social development. Environmentally, PetroCaribe did not negatively or positively impact the environmental quality of the member countries, in the sense that we do not find a significant effect on the trend of urn:x-wiley:14636786:media:manc12275:manc12275-math-0001 emissions per capita
Superstring Scattering from O-planes
We write the vertex operators of massless NS-NS and RR states of Type II
superstring theory in the presence of Orientifold p-planes. They include the
usual vertex operators of Type II theory and their images. We then calculate
the two-point functions of these vertex operators at the projective plane PR_2
level. We show that the result can be written in the Veneziano-type formulae,
with the same kinematic factor that appears in the D_p-branes amplitudes. While
the scattering amplitudes with the usual vertex operators are not gauge
invariant, the above amplitudes are invariant. From the amplitude describing
scattering of two NS-NS states off the O-plane, we find the low energy
effective action of O-planes. The result shows a relative factor 2^{p-6}
between couplings to O-planes and to D-branes at (\alpha')^2 order.Comment: 22 pages, no figure, latex file, v2: minor corrections, version to
appear in Nucl. Phys.
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