503 research outputs found
Deformation Quantization in Singular Spaces
We present a method of quantizing analytic spaces immersed in an
arbitrary smooth ambient manifold . Remarkably our approach can be applied
to singular spaces. We begin by quantizing the cotangent bundle of the manifold
. Using a super-manifold framework we modify the Fedosov construction in a
way such that the -product of the functions lifted from the base
manifold turns out to be the usual commutative product of smooth functions on
. This condition allows us to lift the ideals associated to the analytic
spaces on the base manifold to form left (or right) ideals on
(\mc{O}_{\Omega^1 M}[[\hbar]],\starl) in a way independent of the choice of
generators and leading to a finite set of PDEs defining the functions in the
quantum algebra associated to . Some examples are included.Comment: 14 page
Deformation Quantization of Almost Kahler Models and Lagrange-Finsler Spaces
Finsler and Lagrange spaces can be equivalently represented as almost Kahler
manifolds enabled with a metric compatible canonical distinguished connection
structure generalizing the Levi Civita connection. The goal of this paper is to
perform a natural Fedosov-type deformation quantization of such geometries. All
constructions are canonically derived for regular Lagrangians and/or
fundamental Finsler functions on tangent bundles.Comment: the latex 2e variant of the manuscript accepted for JMP, 11pt, 23
page
BRST quantization of quasi-symplectic manifolds and beyond
We consider a class of \textit{factorizable} Poisson brackets which includes
almost all reasonable Poisson structures. A particular case of the factorizable
brackets are those associated with symplectic Lie algebroids. The BRST theory
is applied to describe the geometry underlying these brackets as well as to
develop a deformation quantization procedure in this particular case. This can
be viewed as an extension of the Fedosov deformation quantization to a wide
class of \textit{irregular} Poisson structures. In a more general case, the
factorizable Poisson brackets are shown to be closely connected with the notion
of -algebroid. A simple description is suggested for the geometry underlying
the factorizable Poisson brackets basing on construction of an odd Poisson
algebra bundle equipped with an abelian connection. It is shown that the
zero-curvature condition for this connection generates all the structure
relations for the -algebroid as well as a generalization of the Yang-Baxter
equation for the symplectic structure.Comment: Journal version, references and comments added, style improve
ЕФЕКТИ ПОДАТКОВИХ ТРАНСФОРМАЦІЙ
The tax reforms in Ukraine last a long time but do not lead to the desirable results. It actualizes the research of mistakes and wrong managerial decisions. The authors consider that the main reason of ineffective tax reforms is ignoring the objective features of taxes and fundamentals of management under policy making. The article aims to prove this hypothesis. The authors use the method of logical assumptions based on the interrelation of objective and subjective as well as the statistical data analysis for evidence. They show that the definition of taxes can be interpreted in different way. It predetermines the tax reform beneficiary: government or society. The Ukrainian government determines the tax reform purposes in abstractive form without quantitative indicators and does not analyses the previous tax transformations results. Such management does not meet the principles that objectively predetermine tax reform successful results. The tax transformations during 2014—2018 led to the tax burden grows. In the result the government revenue increased. At the same time it led to the cutback of consumption demand. The indicators of the pharmacy market and excise goods market development prove this conclusion. Such effect was a logical result of the ignoring objective properties of taxes. Managerial decisions on the tax system reforming contradicted to the purpose of the tax system reform in Ukraine — to provide economic grows. The statistical data demonstrate a little GDP grows. But most of people became much poor through unequal distribution of income. The Ukrainian government did not use the natural properties of tax as regulators of consumption demand through shifting the tax burden from poor sector of population due to towards the income that significantly exceeds the average. The authors suggest the further ways of the tax system reforming in Ukraine.Налоговые реформы в Украине не приводят к желаемым результатам. Считаем, что основной причиной является игнорирование объективных особенностей налогов и основ менеджмента при разработке и реализации налоговой политики. Цель статьи — доказать эту гипотезу. Доказано, что управленческие решения по реформированию налоговой системы противоречат цели реформирования налоговой системы в Украине — обеспечить экономический рост.Податкові реформи в Україні змінюють одна одну, проте не призводить до бажаних результатів. Такий стан речей актуалізує дослідження помилок і неправильних управлінських рішень, які ухвалюють під час реформування. Вважаємо, що головною причиною неефективних податкових реформ є ігнорування об’єктивних особливостей податків та основ менеджменту під час розроблення та реалізації податкової політики. Мета статті — довести цю гіпотезу. У процесі дослідження застосовуємо метод логічних умовиводів на основі взаємозв’язку об’єктивного і суб’єктивного та статистичний аналіз даних. Вони показують, що визначення податків можна трактувати по-різному. Це активізує бенефіціара податкової реформи: уряд чи суспільство. Уряд України визначає цілі податкової реформи в абстрактній формі без кількісних показників і не аналізує результати попередніх податкових трансформацій. Такий підхід не відповідає засадам управління. Податкові трансформації протягом 2014—2018 років призвели до зростання податкового навантаження. У результаті доходи держави зросли. Водночас це призвело до скорочення споживчого попиту. Такий висновок підтверджують показники розвитку фармацевтичного ринку і ринку підакцизних товарів. Ефект був логічним результатом ігнорування об’єктивних властивостей податків. Управлінські рішення щодо реформування податкової системи суперечать меті реформування податкової системи в Україні — забезпечити економічне зростання. Статистичні дані свідчать про незначне зростання ВВП. Але більшість людей стали значно біднішими через нерівномірний розподіл доходів. Український уряд не використовував природні властивості податків як регуляторів споживчого попиту через перенесення податкового тягаря з бідних верств населення на платників, дохід яких значно перевищує середній. Пропонуємо подальші напрями податкових трансформацій
Higher order relations in Fedosov supermanifolds
Higher order relations existing in normal coordinates between affine
extensions of the curvature tensor and basic objects for any Fedosov
supermanifolds are derived. Representation of these relations in general
coordinates is discussed.Comment: 11 LaTex pages, no figure
Scalar Casimir Energies of Tetrahedra
New results for scalar Casimir self-energies arising from interior modes are
presented for the three integrable tetrahedral cavities. Since the eigenmodes
are all known, the energies can be directly evaluated by mode summation, with a
point-splitting regulator, which amounts to evaluation of the cylinder kernel.
The correct Weyl divergences, depending on the volume, surface area, and the
corners, are obtained, which is strong evidence that the counting of modes is
correct. Because there is no curvature, the finite part of the quantum energy
may be unambiguously extracted. Dirichlet and Neumann boundary conditions are
considered and systematic behavior of the energy in terms of geometric
invariants is explored.Comment: Talk given at QFEXT 1
Surface potential at a ferroelectric grain due to asymmetric screening of depolarization fields
Nonlinear screening of electric depolarization fields, generated by a stripe
domain structure in a ferroelectric grain of a polycrystalline material, is
studied within a semiconductor model of ferroelectrics. It is shown that the
maximum strength of local depolarization fields is rather determined by the
electronic band gap than by the spontaneous polarization magnitude.
Furthermore, field screening due to electronic band bending and due to presence
of intrinsic defects leads to asymmetric space charge regions near the grain
boundary, which produce an effective dipole layer at the surface of the grain.
This results in the formation of a potential difference between the grain
surface and its interior of the order of 1 V, which can be of either sign
depending on defect transition levels and concentrations. Exemplary acceptor
doping of BaTiO3 is shown to allow tuning of the said surface potential in the
region between 0.1 and 1.3 V.Comment: 14 pages, 11 figures, submitted to J. Appl. Phy
Stiffness of RBC optical confinement affected by optical clearing
In vivo optical trapping is a novel applied direction of an optical manipulation, which enables one to noninvasive measurement of mechanical properties of cells and tissues in living animals directly. But an application area of this direction is limited because strong scattering of many biological tissues. An optical clearing enables one to decrease the scattering and therefore increase a depth of light penetration, decrease a distortion of light beam, improve a resolution in imaging applications. Now novel methods had appeared for a measurement an optical clearing degree at a cellular level. But these methods aren’t applicable in vivo. In this paper we present novel measurement method of estimate of the optical clearing, which are based on a measurement of optical trap stiffness. Our method may be applicable in vivo
Symplectic geometries on supermanifolds
Extension of symplectic geometry on manifolds to the supersymmetric case is
considered. In the even case it leads to the even symplectic geometry (or,
equivalently, to the geometry on supermanifolds endowed with a non-degenerate
Poisson bracket) or to the geometry on an even Fedosov supermanifolds. It is
proven that in the odd case there are two different scalar symplectic
structures (namely, an odd closed differential 2-form and the antibracket)
which can be used for construction of symplectic geometries on supermanifolds.Comment: LaTex, 1o pages, LaTex, changed conten
Direct Detection of Electroweak-Interacting Dark Matter
Assuming that the lightest neutral component in an SU(2)L gauge multiplet is
the main ingredient of dark matter in the universe, we calculate the elastic
scattering cross section of the dark matter with nucleon, which is an important
quantity for the direct detection experiments. When the dark matter is a real
scalar or a Majorana fermion which has only electroweak gauge interactions, the
scattering with quarks and gluon are induced through one- and two-loop quantum
processes, respectively, and both of them give rise to comparable contributions
to the elastic scattering cross section. We evaluate all of the contributions
at the leading order and find that there is an accidental cancellation among
them. As a result, the spin-independent cross section is found to be
O(10^-(46-48)) cm^2, which is far below the current experimental bounds.Comment: 19 pages, 7 figures, published versio
- …