333 research outputs found
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
Deformation Quantization of Nonholonomic Almost Kahler Models and Einstein Gravity
Nonholonomic distributions and adapted fame structures on (pseudo) Riemannian
manifolds of even dimension are employed to build structures equivalent to
almost Kahler geometry and which allows to perform a Fedosov-like quantization
of gravity. The nonlinear connection formalism that was formally elaborated for
Lagrange and Finsler geometry is implemented in classical and quantum Einstein
gravity.Comment: latex 2e, 11pt, 15 pages, v4 accepted by Phys. Lett.
Symplectic connections, Noncommutative Yang Mills theory and Supermembranes
In built noncommutativity of supermembranes with central charges in eleven
dimensions is disclosed. This result is used to construct an action for a
noncommutative supermembrane where interesting topological terms appear. In
order to do so, we first set up a global formulation for noncommutative Yang
Mills theory over general symplectic manifolds. We make the above constructions
following a pure geometrical procedure using the concept of connections over
Weyl algebra bundles on symplectic manifolds. The relation between
noncommutative and ordinary supermembrane actions is discussed.Comment: 18 page
Fedosov Quantization of Lagrange-Finsler and Hamilton-Cartan Spaces and Einstein Gravity Lifts on (Co) Tangent Bundles
We provide a method of converting Lagrange and Finsler spaces and their
Legendre transforms to Hamilton and Cartan spaces into almost Kaehler
structures on tangent and cotangent bundles. In particular cases, the Hamilton
spaces contain nonholonomic lifts of (pseudo) Riemannian / Einstein metrics on
effective phase spaces. This allows us to define the corresponding Fedosov
operators and develop deformation quantization schemes for nonlinear mechanical
and gravity models on Lagrange- and Hamilton-Fedosov manifolds.Comment: latex2e, 11pt, 35 pages, v3, accepted to J. Math. Phys. (2009
Non-Abelian Conversion and Quantization of Non-scalar Second-Class Constraints
We propose a general method for deformation quantization of any second-class
constrained system on a symplectic manifold. The constraints determining an
arbitrary constraint surface are in general defined only locally and can be
components of a section of a non-trivial vector bundle over the phase-space
manifold. The covariance of the construction with respect to the change of the
constraint basis is provided by introducing a connection in the ``constraint
bundle'', which becomes a key ingredient of the conversion procedure for the
non-scalar constraints. Unlike in the case of scalar second-class constraints,
no Abelian conversion is possible in general. Within the BRST framework, a
systematic procedure is worked out for converting non-scalar second-class
constraints into non-Abelian first-class ones. The BRST-extended system is
quantized, yielding an explicitly covariant quantization of the original
system. An important feature of second-class systems with non-scalar
constraints is that the appropriately generalized Dirac bracket satisfies the
Jacobi identity only on the constraint surface. At the quantum level, this
results in a weakly associative star-product on the phase space.Comment: LaTeX, 21 page
Weyl-Wigner Formulation of Noncommutative Quantum Mechanics
We address the phase space formulation of a noncommutative extension of
quantum mechanics in arbitrary dimension, displaying both spatial and momentum
noncommutativity. By resorting to a covariant generalization of the Weyl-Wigner
transform and to the Seiberg-Witten map we construct an isomorphism between the
operator and the phase space representations of the extended Heisenberg
algebra. This map provides a systematic approach to derive the entire structure
of noncommutative quantum mechanics in phase space. We construct the extended
starproduct, Moyal bracket and propose a general definition of noncommutative
states. We study the dynamical and eigenvalue equations of the theory and prove
that the entire formalism is independent of the particular choice of
Seiberg-Witten map. Our approach unifies and generalizes all the previous
proposals for the phase space formulation of noncommutative quantum mechanics.
For concreteness we rederive these proposals by restricting our formalism to
some 2-dimensional spaces.Comment: Revtex4, 3 diagrams, 32 page
Deformation quantization of cosmological models
The Weyl-Wigner-Groenewold-Moyal formalism of deformation quantization is
applied to cosmological models in the minisuperspace. The quantization
procedure is performed explicitly for quantum cosmology in a flat
minisuperspace. The de Sitter cosmological model is worked out in detail and
the computation of the Wigner functions for the Hartle-Hawking, Vilenkin and
Linde wave functions are done numerically. The Wigner function is analytically
calculated for the Kantowski-Sachs model in (non)commutative quantum cosmology
and for string cosmology with dilaton exponential potential. Finally, baby
universes solutions are described in this context and the Wigner function is
obtained.Comment: 37 pages, 16 figure
Cohomologies of the Poisson superalgebra
Cohomology spaces of the Poisson superalgebra realized on smooth
Grassmann-valued functions with compact support on ($C^{2n}) are
investigated under suitable continuity restrictions on cochains. The first and
second cohomology spaces in the trivial representation and the zeroth and first
cohomology spaces in the adjoint representation of the Poisson superalgebra are
found for the case of a constant nondegenerate Poisson superbracket for
arbitrary n>0. The third cohomology space in the trivial representation and the
second cohomology space in the adjoint representation of this superalgebra are
found for arbitrary n>1.Comment: Comments: 40 pages, the text to appear in Theor. Math. Phys.
supplemented by computation of the 3-rd trivial cohomolog
Weyl's symbols of Heisenberg operators of canonical coordinates and momenta as quantum characteristics
The knowledge of quantum phase flow induced under the Weyl's association rule
by the evolution of Heisenberg operators of canonical coordinates and momenta
allows to find the evolution of symbols of generic Heisenberg operators. The
quantum phase flow curves obey the quantum Hamilton's equations and play the
role of characteristics. At any fixed level of accuracy of semiclassical
expansion, quantum characteristics can be constructed by solving a coupled
system of first-order ordinary differential equations for quantum trajectories
and generalized Jacobi fields. Classical and quantum constraint systems are
discussed. The phase-space analytic geometry based on the star-product
operation can hardly be visualized. The statement "quantum trajectory belongs
to a constraint submanifold" can be changed e.g. to the opposite by a unitary
transformation. Some of relations among quantum objects in phase space are,
however, left invariant by unitary transformations and support partly geometric
relations of belonging and intersection. Quantum phase flow satisfies the
star-composition law and preserves hamiltonian and constraint star-functions.Comment: 27 pages REVTeX, 6 EPS Figures. New references added. Accepted for
publication to JM
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