1,566 research outputs found
Weak Mirror Symmetry of Complex Symplectic Algebras
A complex symplectic structure on a Lie algebra \lie h is an integrable
complex structure with a closed non-degenerate -form. It is
determined by and the real part of the -form. Suppose that
\lie h is a semi-direct product \lie g\ltimes V, and both \lie g and
are Lagrangian with respect to and totally real with respect to .
This note shows that \lie g\ltimes V is its own weak mirror image in the
sense that the associated differential Gerstenhaber algebras controlling the
extended deformations of and are isomorphic. The geometry of
on the semi-direct product \lie g\ltimes V is also shown to be
equivalent to that of a torsion-free flat symplectic connection on the Lie
algebra \lie g. By further exploring a relation between with
hypersymplectic algebras, we find an inductive process to build families of
complex symplectic algebras of dimension from the data of the
-dimensional ones.Comment: 22 page
Scattering mechanism in a step-modulated subwavelength metal slit: a multi-mode multi-reflection analysis
In this paper, the scattering/transmission inside a step-modulated
subwavelength metal slit is investigated in detail. We firstly investigate the
scattering in a junction structure by two types of structural changes. The
variation of transmission and reflection coefficients depending on structural
parameters are analyzed. Then a multi-mode multi-reflection model based on ray
theory is proposed to illustrate the transmission in the step-modulated slit
explicitly. The key parts of this model are the multi-mode excitation and the
superposition procedure of the scatterings from all possible modes, which
represent the interference and energy transfer happened at interfaces. The
method we use is an improved modal expansion method (MEM), which is a more
practical and efficient version compared with the previous one [Opt. Express
19, 10073 (2011)]. In addition, some commonly used methods, FDTD, scattering
matrix method, and improved characteristic impedance method, are compared with
MEM to highlight the preciseness of these methods.Comment: 25 pages, 9 figure
BPS R-balls in N=4 SYM on R X S^3, Quantum Hall Analogy and AdS/CFT Holography
In this paper, we propose a new approach to study the BPS dynamics in N=4
supersymmetric U(N) Yang-Mills theory on R X S^3, in order to better understand
the emergence of gravity in the gauge theory. Our approach is based on
supersymmetric, space-filling Q-balls with R-charge, which we call R-balls. The
usual collective coordinate method for non-topological scalar solitons is
applied to quantize the half and quarter BPS R-balls. In each case, a different
quantization method is also applied to confirm the results from the collective
coordinate quantization. For finite N, the half BPS R-balls with a U(1)
R-charge have a moduli space which, upon quantization, results in the states of
a quantum Hall droplet with filling factor one. These states are known to
correspond to the ``sources'' in the Lin-Lunin-Maldacena geometries in IIB
supergravity. For large N, we find a new class of quarter BPS R-balls with a
non-commutativity parameter. Quantization on the moduli space of such R-balls
gives rise to a non-commutative Chern-Simons matrix mechanics, which is known
to describe a fractional quantum Hall system. In view of AdS/CFT holography,
this demonstrates a profound connection of emergent quantum gravity with
non-commutative geometry, of which the quantum Hall effect is a special case.Comment: 42 pages, 2 figures; v3: a new paragraph on counting unbroken susy of
NC R-balls and references adde
Density Matrix in Quantum Mechanics and Distinctness of Ensembles Having the Same Compressed Density Matrix
We clarify different definitions of the density matrix by proposing the use
of different names, the full density matrix for a single-closed quantum system,
the compressed density matrix for the averaged single molecule state from an
ensemble of molecules, and the reduced density matrix for a part of an
entangled quantum system, respectively. We show that ensembles with the same
compressed density matrix can be physically distinguished by observing
fluctuations of various observables. This is in contrast to a general belief
that ensembles with the same compressed density matrix are identical. Explicit
expression for the fluctuation of an observable in a specified ensemble is
given. We have discussed the nature of nuclear magnetic resonance quantum
computing. We show that the conclusion that there is no quantum entanglement in
the current nuclear magnetic resonance quantum computing experiment is based on
the unjustified belief that ensembles having the same compressed density matrix
are identical physically. Related issues in quantum communication are also
discussed.Comment: 26 pages. To appear in Foundations of Physics, 36 (8), 200
Digoxin net secretory transport in bronchial epithelial cell layers is not exclusively mediated by P-glycoprotein/MDR1
Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-No Derivative Works License, which permits non-commercial use, distribution, and reproduction in any medium, provided the original author and source are creditedThe impact of P-glycoprotein (MDR1, ABCB1) on drug disposition in the lungs as well as its presence and activity in in vitro respiratory drug absorption models remain controversial to date. Hence, we characterised MDR1 expression and the bidirectional transport of the common MDR1 probe 3H-digoxin in air-liquid interfaced (ALI) layers of normal human bronchial epithelial (NHBE) cells and of the Calu-3 bronchial epithelial cell line at different passage numbers. Madin-Darby Canine Kidney (MDCKII) cells transfected with the human MDR1 were used as positive controls. 3H-digoxin efflux ratio (ER) was low and highly variable in NHBE layers. In contrast, ER=11.4 or 3.0 was measured in Calu-3 layers at a low or high passage number, respectively. These were, however, in contradiction with increased MDR1 protein levels observed upon passaging. Furthermore, ATP depletion and the two MDR1 inhibitory antibodies MRK16 and UIC2 had no or only a marginal impact on 3H-digoxin net secretory transport in the cell line. Our data do not support an exclusive role of MDR1 in 3H-digoxin apparent efflux in ALI Calu-3 layers and suggest the participation of an ATP-independent carrier. Identification of this transporter might provide a better understanding of drug distribution in the lungs.Peer reviewe
Electroweak Corrections to the Charged Higgs Boson Decay into Chargino and Neutralino
The electroweak corrections to the partial widths of the decays including one-loop
diagrams of the third generation quarks and squarks, are investigated within
the Supersymmetric Standard Model. The relative corrections can reach the
values about 10%, therefore they should be taken into account for the precise
experimental measurement at future colliders.Comment: 21 pages, 6 eps figures, 1 Latex fil
Systematic Cu-63 NQR studies of the stripe phase in La(1.6-x)Nd(0.4)Sr(x)CuO(4) for 0.07 <= x <= 0.25
We demonstrate that the integrated intensity of Cu-63 nuclear quadrupole
resonance (NQR) in La(1.6-x)Nd(0.4)Sr(x)CuO(4) decreases dramatically below the
charge-stripe ordering temperature T(charge). Comparison with neutron and X-ray
scattering indicates that the wipeout fraction F(T) (i.e. the missing fraction
of the integrated intensity of the NQR signal) represents the charge-stripe
order parameter. The systematic study reveals bulk charge-stripe order
throughout the superconducting region 0.07 <= x <= 0.25. As a function of the
reduced temperature t = T/T(charge), the temperature dependence of F(t) is
sharpest for the hole concentration x=1/8, indicating that x=1/8 is the optimum
concentration for stripe formation.Comment: 10 pages of text and captions, 11 figures in postscript. Final
version, with new data in Fig.
Electronic structure in underdoped cuprates due to the emergence of a pseudogap
The phenomenological Green's function developed in the works of Yang, Rice
and Zhang has been very successful in understanding many of the anomalous
superconducting properties of the deeply underdoped cuprates. It is based on
considerations of the resonating valence bond spin liquid approximation and is
designed to describe the underdoped regime of the cuprates. Here we emphasize
the region of doping, , just below the quantum critical point at which the
pseudogap develops. In addition to Luttinger hole pockets centered around the
nodal direction, there are electron pockets near the antinodes which are
connected to the hole pockets by gapped bridging contours. We determine the
contours of nearest approach as would be measured in angular resolved
photoemission experiments and emphasize signatures of the Fermi surface
reconstruction from the large Fermi contour of Fermi liquid theory (which
contains hole states) to the Luttinger pocket (which contains hole
states). We find that the quasiparticle effective mass renormalization
increases strongly towards the edge of the Luttinger pockets beyond which it
diverges.Comment: 11 pages, 9 figure
Direct Measurements of the Branching Fractions for and and Determinations of the Form Factors and
The absolute branching fractions for the decays and
are determined using singly
tagged sample from the data collected around 3.773 GeV with the
BES-II detector at the BEPC. In the system recoiling against the singly tagged
meson, events for and events for decays are observed. Those yield
the absolute branching fractions to be and . The
vector form factors are determined to be
and . The ratio of the two form
factors is measured to be .Comment: 6 pages, 5 figure
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