103 research outputs found
Noncommutative N=1 super Yang-Mills, the Seiberg-Witten map and UV divergences
Classically, the dual under the Seiberg-Witten map of noncommutative U(N),
{\cal N}=1 super Yang-Mills theory is a field theory with ordinary gauge
symmetry whose fields carry, however, a \theta-deformed nonlinear realisation
of the {\cal N}=1 supersymmetry algebra in four dimensions. For the latter
theory we work out at one-loop and first order in the noncommutative parameter
matrix \theta^{\mu\nu} the UV divergent part of its effective action in the
background-field gauge, and, for N>=2, we show that for finite values of N the
gauge sector fails to be renormalisable; however, in the large N limit the full
theory is renormalisable, in keeping with the expectations raised by the
quantum behaviour of the theory's noncommutative classical dual. We also obtain
--for N>=3, the case with N=2 being trivial-- the UV divergent part of the
effective action of the SU(N) noncommutative theory in the enveloping-algebra
formalism that is obtained from the previous ordinary U(N) theory by removing
the U(1) degrees of freedom. This noncommutative SU(N) theory is also
renormalisable.Comment: 33 pages, 4 figures. Version 2: Unnecessary files removed. Version 3:
New types of field redefinitions were considered, which make the large N U(N)
and the SU(N) theories renormalisable. The conclusions for U(N) with finite N
remain unchanged. Version 4: Corrected mistyped equations, minor revision
Hidden parameters in open-system evolution unveiled by geometric phase
We find a class of open-system models in which individual quantum
trajectories may depend on parameters that are undetermined by the full
open-system evolution. This dependence is imprinted in the geometric phase
associated with such trajectories and persists after averaging. Our findings
indicate a potential source of ambiguity in the quantum trajectory approach to
open quantum systems.Comment: QSD analysis added; several stylistic changes; journal reference
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Renormalizability of noncommutative SU(N) gauge theory
We analyze the renormalizability properties of pure gauge noncommutative
SU(N) theory in the -expanded approach. We find that the theory is
one-loop renormalizable to first order in .Comment: 11 pages, minor changes, accepted for publication in JHE
Emergence of classical behavior from the quantum spin
Classical Hamiltonian system of a point moving on a sphere of fixed radius is
shown to emerge from the constrained evolution of quantum spin. The constrained
quantum evolution corresponds to an appropriate coarse-graining of the quantum
states into equivalence classes, and forces the equivalence classes to evolve
as single units representing the classical states. The coarse-grained quantum
spin with the constrained evolution in the limit of the large spin becomes
indistinguishable from the classical system
Metric approach to quantum constraints
A new framework for deriving equations of motion for constrained quantum
systems is introduced, and a procedure for its implementation is outlined. In
special cases the framework reduces to a quantum analogue of the Dirac theory
of constrains in classical mechanics. Explicit examples involving spin-1/2
particles are worked out in detail: in one example our approach coincides with
a quantum version of the Dirac formalism, while the other example illustrates
how a situation that cannot be treated by Dirac's approach can nevertheless be
dealt with in the present scheme.Comment: 13 pages, 1 figur
TeV Scale Implications of Non Commutative Space time in Laboratory Frame with Polarized Beams
We analyze , and processes within the
Seiberg-Witten expanded noncommutative scenario using polarized beams. With
unpolarized beams the leading order effects of non commutativity starts from
second order in non commutative(NC) parameter i.e. , while with
polarized beams these corrections appear at first order () in cross
section. The corrections in Compton case can probe the magnetic
component() while in Pair production and Pair annihilation
probe the electric component() of NC parameter. We include the
effects of earth rotation in our analysis. This study is done by investigating
the effects of non commutativity on different time averaged cross section
observables. The results which also depends on the position of the collider,
can provide clear and distinct signatures of the model testable at the
International Linear Collider(ILC).Comment: 22 pages, 19 figures, new comments and references added, few typos
corrected, Published in JHE
Dyons in Nonabelian Born-Infeld Theory
We analyze a nonabelian extension of Born--Infeld action for the SU(2) group.
In the class of spherically symmetric solutions we find that, besides the
Gal'tsov--Kerner glueballs, only the analytic dyons have finite energy. The
presented analytic and numerical investigation excludes the existence of pure
magnetic monopoles of 't Hooft--Polyakov type.Comment: 12 pages, 3 figure
MEDICINAL PROPERTIES OF BUCKWHEAT PRODUCTS AND HONEY IN COMPLIANCE WITH FOOD SAFETY REGULATORY REQUIREMENTS
Buckwheat (Fagopyrum esculentum Moench) is a gluten-free pseudo-cereal and honey plant. Buckwheat grain yields vary greatly and depend on the genotype, agro-ecological conditions of production and harvesting method. The grain yield of the 'Novosadska' variety variеs 1.5-3 t ha-1and the honey yield amounts and more than 300 kg ha-1. Buckwheat grain contains: carbohydrates, proteins, fats, organic acids and rutin (quercetin-3-rutinosid), minerals (potassium, phosphorus, calcium, magnesium, sodium, iodine, zinc, bromine and iron), vitamins (D2-ergokalciferol, D3-holekalciferol, P-bioflavonoids, vitamins group B: B1-Thiamine, B2-Riboflavin, B3-niacin, B4-Choline, B5-Pantothenic acid, B6-Piridoxin, B9-Folate; and vitamin E-Tocopherols. 'Novosadska' buckwheat contains the highest level of phenolic acids, proanthocyanidins, flavones and flavonols. Buckwheat honey is dark color, which it gets from polyphenols. Polyphenols is antioxidants, organic compounds which affect the quality of food, especially the color and taste. In accordance with the law on food safety, the interests of consumers must be ensured the highest level of protection. Phenolic antioxidants from honey are bioavailable and increase the antioxidant activity of plasma. Buckwheat honey has a beneficial effect on bronchitis and cough, hypertension, arteriosclerosis, of heart disease, liver and intestinal diseases and has antibacterial effects
Recent trends in daily rainfall extremes over Montenegro (1951-2010)
More intense rainfall may cause a range of negative impacts upon society and the environment. In this study we analysed trends in extreme ETCCDI (Expert Team on Climate Change Detection and Indices) rainfall indices in Montenegro for the period between 1951 and 2010. Montenegro has been poorly studied in terms of rainfall extremes, yet it contains the wettest Mediterranean region known as Krivosije. Several indices of precipitation extremes were assessed including the number of dry days and rainfall totals in order to identify trends and possible changes. A spatial pattern relationship between extreme rainfall indices and the North Atlantic Oscillation has also been examined. The results generally suggest that the number of days with precipitation decreased while rainfall intensity increased, particularly in south-western parts of the country. A slight tendency towards intense rainfall events is suggested. The examined rainfall indices and North Atlantic Oscillation over Montenegro seemed to be directly linked to changes in one of the major large-scale circulation modes such as the NAO pattern that is particularly evident during the winter season
The one-loop renormalization of the gauge sector in the noncommutative standard model
In this paper we construct a version of the standard model gauge sector on
noncommutative space-time which is one-loop renormalizable to first order in
the expansion in the noncommutativity parameter . The one-loop
renormalizability is obtained by the Seiberg-Witten redefinition of the
noncommutative gauge potential for the model containing the usual six
representations of matter fields of the first generation.Comment: 16 pages, 2 figure
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