390 research outputs found
Poisson Brackets of Normal-Ordered Wilson Loops
We formulate Yang-Mills theory in terms of the large-N limit, viewed as a
classical limit, of gauge-invariant dynamical variables, which are closely
related to Wilson loops, via deformation quantization. We obtain a Poisson
algebra of these dynamical variables corresponding to normal-ordered quantum
(at a finite value of ) operators. Comparing with a Poisson algebra one
of us introduced in the past for Weyl-ordered quantum operators, we find, using
ideas closly related to topological graph theory, that these two Poisson
algebras are, roughly speaking, the same. More precisely speaking, there exists
an invertible Poisson morphism between them.Comment: 34 pages, 4 eps figures, LaTeX2.09; citations adde
Simple Non Linear Klein-Gordon Equations in 2 space dimensions, with long range scattering
We establish that solutions, to the most simple NLKG equations in 2 space
dimensions with mass resonance, exhibits long range scattering phenomena.
Modified wave operators and solutions are constructed for these equations. We
also show that the modified wave operators can be chosen such that they
linearize the non-linear representation of the Poincar\'e group defined by the
NLKG.Comment: 19 pages, LaTeX, To appear in Lett. Math. Phy
From Classical to Quantum Mechanics: "How to translate physical ideas into mathematical language"
In this paper, we investigate the connection between Classical and Quantum
Mechanics by dividing Quantum Theory in two parts: - General Quantum Axiomatics
(a system is described by a state in a Hilbert space, observables are
self-adjoint operators and so on) - Quantum Mechanics properly that specifies
the Hilbert space, the Heisenberg rule, the free Hamiltonian... We show that
General Quantum Axiomatics (up to a supplementary "axiom of classicity") can be
used as a non-standard mathematical ground to formulate all the ideas and
equations of ordinary Classical Statistical Mechanics. So the question of a
"true quantization" with "h" must be seen as an independent problem not
directly related with quantum formalism. Moreover, this non-standard
formulation of Classical Mechanics exhibits a new kind of operation with no
classical counterpart: this operation is related to the "quantization process",
and we show why quantization physically depends on group theory (Galileo
group). This analytical procedure of quantization replaces the "correspondence
principle" (or canonical quantization) and allows to map Classical Mechanics
into Quantum Mechanics, giving all operators of Quantum Mechanics and
Schrodinger equation. Moreover spins for particles are naturally generated,
including an approximation of their interaction with magnetic fields. We find
also that this approach gives a natural semi-classical formalism: some exact
quantum results are obtained only using classical-like formula. So this
procedure has the nice property of enlightening in a more comprehensible way
both logical and analytical connection between classical and quantum pictures.Comment: 47 page
Closedness of star products and cohomologies
We first review the introduction of star products in connection with
deformations of Poisson brackets and the various cohomologies that are related
to them. Then we concentrate on what we have called ``closed star products" and
their relations with cyclic cohomology and index theorems. Finally we shall
explain how quantum groups, especially in their recent topological form, are in
essence examples of star products.Comment: 16 page
Improved Implementation of Point Location in General Two-Dimensional Subdivisions
We present a major revamp of the point-location data structure for general
two-dimensional subdivisions via randomized incremental construction,
implemented in CGAL, the Computational Geometry Algorithms Library. We can now
guarantee that the constructed directed acyclic graph G is of linear size and
provides logarithmic query time. Via the construction of the Voronoi diagram
for a given point set S of size n, this also enables nearest-neighbor queries
in guaranteed O(log n) time. Another major innovation is the support of general
unbounded subdivisions as well as subdivisions of two-dimensional parametric
surfaces such as spheres, tori, cylinders. The implementation is exact,
complete, and general, i.e., it can also handle non-linear subdivisions. Like
the previous version, the data structure supports modifications of the
subdivision, such as insertions and deletions of edges, after the initial
preprocessing. A major challenge is to retain the expected O(n log n)
preprocessing time while providing the above (deterministic) space and
query-time guarantees. We describe an efficient preprocessing algorithm, which
explicitly verifies the length L of the longest query path in O(n log n) time.
However, instead of using L, our implementation is based on the depth D of G.
Although we prove that the worst case ratio of D and L is Theta(n/log n), we
conjecture, based on our experimental results, that this solution achieves
expected O(n log n) preprocessing time.Comment: 21 page
S^1 \times S^2 as a bag membrane and its Einstein-Weyl geometry
In the hybrid skyrmion in which an Anti-de Sitter bag is imbedded into the
skyrmion configuration a S^{1}\times S^{2} membrane is lying on the
compactified spatial infinity of the bag [H. Rosu, Nuovo Cimento B 108, 313
(1993)]. The connection between the quark degrees of freedom and the mesonic
ones is made through the membrane, in a way that should still be clarified from
the standpoint of general relativity and topology. The S^1 \times S^2 membrane
as a 3-dimensional manifold is at the same time a Weyl-Einstein space. We make
here an excursion through the mathematical body of knowledge in the
differential geometry and topology of these spaces which is expected to be
useful for hadronic membranesComment: 9pp in latex, minor correction
Anti de Sitter Holography via Sekiguchi Decomposition
In the present paper we start consideration of anti de Sitter holography in
the general case of the (q+1)-dimensional anti de Sitter bulk with boundary
q-dimensional Minkowski space-time. We present the group-theoretic foundations
that are necessary in our approach. Comparing what is done for q=3 the new
element in the present paper is the presentation of the bulk space as the
homogeneous space G/H = SO(q,2)/SO(q,1), which homogeneous space was studied by
Sekiguchi.Comment: 10 pages, to appear in the Proceedings of the XI International
Workshop "Lie Theory and Its Applications in Physics", (Varna, Bulgaria, June
2015
Symplectic connections and Fedosov's quantization on supermanifolds
A (biased and incomplete) review of the status of the theory of symplectic
connections on supermanifolds is presented. Also, some comments regarding
Fedosov's technique of quantization are made.Comment: Submitted to J. of Phys. Conf. Se
Conformal Maxwell theory as a singleton field theory on AdS_5, IIB three-branes and duality
We examine the boundary conditions associated with extended supersymmetric
Maxwell theory in 5-dimensional anti-De Sitter space. Excitations on the
boundary are identical to those of ordinary 4-dimensional conformal invariant
super electrodynammics. Extrapolations of these excitations give rise to a
5-dimensional topological gauge theory of the singleton type. The possibility
of a connection of this phenomenon to the world volume theory of 3-branes in
IIB string theory is discussed.Comment: 19 pages, TeX, no figures; v2: misprints corrected, references added,
discussion on Chern-Simons couplings revised. v3: References added, misprints
corrected and a discussion in section 2 revised. v4: Typos corrected and
reference adde
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