6,712 research outputs found
One-dimensional structures behind twisted and untwisted superYang-Mills theory
We give a one-dimensional interpretation of the four-dimensional twisted N=1
superYang-Mills theory on a Kaehler manifold by performing an appropriate
dimensional reduction. We prove the existence of a 6-generator superalgebra,
which does not possess any invariant Lagrangian but contains two different
subalgebras that determine the twisted and untwisted formulations of the N=1
superYang-Mills theory.Comment: 12 pages. Final version to appear in Lett. Math. Phys. with improved
notation and misprints correcte
Long-distance entanglement and quantum teleportation in XX spin chains
Isotropic XX models of one-dimensional spin-1/2 chains are investigated with
the aim to elucidate the formal structure and the physical properties that
allow these systems to act as channels for long-distance, high-fidelity quantum
teleportation. We introduce two types of models: I) open, dimerized XX chains,
and II) open XX chains with small end bonds. For both models we obtain the
exact expressions for the end-to-end correlations and the scaling of the energy
gap with the length of the chain. We determine the end-to-end concurrence and
show that model I) supports true long-distance entanglement at zero
temperature, while model II) supports {\it ``quasi long-distance''}
entanglement that slowly falls off with the size of the chain. Due to the
different scalings of the gaps, respectively exponential for model I) and
algebraic in model II), we demonstrate that the latter allows for efficient
qubit teleportation with high fidelity in sufficiently long chains even at
moderately low temperatures.Comment: 9 pages, 6 figure
The Determination of Metals in Welding Fume by X-Ray-Spectrometry
Analysis of the current hygienic situation in the welding production showed that the intensification of welding processes involves the deterioration of air quality, which negatively affects the welders health. Respiratory effects seen in full-time welders have included bronchitis, airway irritation, lung function changes, and a possible increase in the incidence of lung cancer. The metal concentration in the air of the working area have been determined using the photometric method of analysis, which involves the stage of decomposition of the sample material before analysis. However, losses of the analyzed elements are possible when the sample is decomposed. The X-ray fluorescence method of analysis has the advantage of being nondestructive. The investigations shown the data of photometric determination of metals in welding aerosols is 1.5(-:)2 times lower than the results of X-ray fluorescence analysis
Oxidative dehydrogenation of 2,3,5-trimethyl-1,4-hydroquinone in the presence of titanium dioxide hydrogel
Liquid-phase oxidative dehydrogenation of 2,3,5-trimethyl-1,4-hydroquinone in the presence of titanium dioxide hydrogel was studied by a kinetic method. Associative interactions between the substrate, oxidant, and gel were detected by voltammetry and ESR and IR spectroscopy.Russian Foundation for Basic Researc
On Supergroups with Odd Clifford Parameters and Supersymmetry with Modified Leibniz Rule
We investigate supergroups with Grassmann parameters replaced by odd Clifford
parameters. The connection with non-anticommutative supersymmetry is discussed.
A Berezin-like calculus for odd Clifford variables is introduced. Fermionic
covariant derivatives for supergroups with odd Clifford variables are derived.
Applications to supersymmetric quantum mechanics are made. Deformations of the
original supersymmetric theories are encountered when the fermionic covariant
derivatives do not obey the graded Leibniz property. The simplest non-trivial
example is given by the N=2 SQM with a real multiplet and a cubic
potential. The action is real. Depending on the overall sign ("Euclidean" or
"Lorentzian") of the deformation, a Bender-Boettcher pseudo-hermitian
hamiltonian is encountered when solving the equation of motion of the auxiliary
field. A possible connection of our framework with the Drinfeld twist
deformation of supersymmetry is pointed out.Comment: Final version to be published in Int. J. Mod. Phys. A; 20 page
On Graph-Theoretic Identifications of Adinkras, Supersymmetry Representations and Superfields
In this paper we discuss off-shell representations of N-extended
supersymmetry in one dimension, ie, N-extended supersymmetric quantum
mechanics, and following earlier work on the subject codify them in terms of
certain graphs, called Adinkras. This framework provides a method of generating
all Adinkras with the same topology, and so also all the corresponding
irreducible supersymmetric multiplets. We develop some graph theoretic
techniques to understand these diagrams in terms of a relatively small amount
of information, namely, at what heights various vertices of the graph should be
"hung".
We then show how Adinkras that are the graphs of N-dimensional cubes can be
obtained as the Adinkra for superfields satisfying constraints that involve
superderivatives. This dramatically widens the range of supermultiplets that
can be described using the superspace formalism and organizes them. Other
topologies for Adinkras are possible, and we show that it is reasonable that
these are also the result of constraining superfields using superderivatives.
The family of Adinkras with an N-cubical topology, and so also the sequence
of corresponding irreducible supersymmetric multiplets, are arranged in a
cyclical sequence called the main sequence. We produce the N=1 and N=2 main
sequences in detail, and indicate some aspects of the situation for higher N.Comment: LaTeX, 58 pages, 52 illustrations in color; minor typos correcte
Stealth and equiluminous materials for scattering cancellation and wave diffusion
We report a procedure to design 2-dimensional acoustic structures with
prescribed scattering properties. The structures are designed from targeted
properties in the reciprocal space so that their structure factors, i.e., their
scattering patterns under the Born approximation, exactly follow the desired
scattering properties for a set of wavelengths. The structures are made of a
distribution of rigid circular cross-sectional cylinders embedded in air. We
demonstrate the efficiency of the procedure by designing 2-dimensional stealth
acoustic materials with broadband backscattering suppression independent of the
angle of incidence and equiluminous acoustic materials exhibiting broadband
scattering of equal intensity also independent of the angle of incidence. The
scattering intensities are described in terms of both single and multiple
scattering formalisms, showing excellent agreement with each other, thus
validating the scattering properties of each material
Stealth and equiluminous materials for scattering cancellation and wave diffusion
[EN] We report a procedure to design two-dimensional acoustic structures with prescribed scattering properties. The structures are designed from targeted properties in the reciprocal space so that their structure factors, i.e. their scattering patterns under the Born approximation, exactly follow the desired scattering properties for a set of wavelengths. The structures are made of a distribution of rigid circular cross-sectional cylinders embedded in air. We demonstrate the efficiency of the procedure by designing two-dimensional stealth acoustic materials with broadband back-scattering suppression independent of the angle of incidence and equiluminous acoustic materials exhibiting broadband scattering of equal intensity also independent of the angle of incidence. The scattering intensities are described in terms of both single and multiple scattering formalisms, showing excellent agreement with each other, thus validating the scattering properties of each material.This work has been funded by the project Conseil Regional des Pays de la Loire HYPERMETA under the program Etoiles Montantes of the Region Pays de la Loire, by the project Agence Nationale de la Recherche ANR-RGC METARoom [grant number (ANR-18-CE08-0021)] and by the project PID2020112759GB-I00 of the Ministerio de Ciencia e Innovacion.Kuznetsova, S.; Groby, JP.; García-Raffi, LM.; Romero-García, V. (2021). Stealth and equiluminous materials for scattering cancellation and wave diffusion. Waves in Random and Complex Media. https://doi.org/10.1080/17455030.2021.194863
- …