Fourier Duality as a Quantization PrincipleThe Weyl-Wigner prescription for quantization on Euclidean phase spaces makes essential use of Fourier duality. The extension of this property to more general phase spaces requires the use of Kac…R. Aldrovandi, L. A. Saeger·Aug 27, 1996SaveLearn
Projective Fourier Duality and Weyl QuantizationThe Weyl-Wigner correspondence prescription, which makes large use of Fourier duality, is reexamined from the point of view of Kac algebras, the most general background for noncommutative Fourier…R. Aldrovandi, L. A. Saeger·Aug 27, 1996SaveLearn
Operator of fractional derivative in the complex planeThe paper deals with a fractional derivative introduced by means of the Fourier transform. The explicit form of the kernel of general derivative operator acting on the functions analytic on a curve…P. Zavada·Aug 12, 1996SaveLearn
Quantized Kronecker flows and almost periodic quantum field theoryWe define and study the properties of the infinite dimensional quantized Kronecker flow. This *-dynamical system arises as a quantization of the corresponding flow on an infinite dimensional…Slawomir Klimek, Andrzej Lesniewski·Aug 12, 1996SaveLearn
The stable rank of some free product C*-algebrasIt is proved that the reduced group C*-algebra C*red(G) has stable rank one (i.e. its group of invertible elements is a dense subset) if G is a discrete group arising as a free product G1*G2…Ken Dykema, Uffe Haagerup, Mikael Rordam·Aug 9, 1996SaveLearn
Abundance of invariant and almost invariant pure states of C*-dynamical systemsWe show that invariant states of C*-dynamical systems can be approximated in the weak*-topology by invariant pure states, or almost invariant pure states, under various circumstances.Ola Bratteli, Akitaka Kishimoto, Derek W. Robinson·Jul 29, 1996SaveLearn
On self-adjointness of a Schroedinger operatorLet M be a complete Riemannian manifold and let Ω*(M) denote the space of differential forms on M. Let d:Ω*(M) Ω*+1(M) be the exterior differential operator and let =dd*+d*d…Maxim Braverman·Jul 28, 1996SaveLearn
Covariant SPDEs and Quantum Field StructuresCovariant stochastic partial differential equations are studied in any dimension. A special class of such equations is selected and it is proven that the solutions can be analytically continued to…C. Becker, R. Gielerak, P. Ługiewicz·Jul 4, 1996SaveLearn
Homology of pseudodifferential operators I. Manifolds with boundaryThe Hochschild and cyclic homology groups are computed for the algebra of `cusp' pseudodifferential operators on any compact manifold with boundary. The index functional for this algebra is…Richard B. Melrose, Victor Nistor·Jun 21, 1996SaveLearn
Super-connections and non-commutative geometryWe show that Quillen's formalism for computing the Chern character of the index using superconnections extends to arbitrary operators with functional calculus. We thus remove the condition that…Victor Nistor·Jun 14, 1996SaveLearn
Node Theorem for Matrix Schroedinger OperatorsIn this paper we study the ground states of a matrix Schroedinger operator, that is an operator of the type (-Laplace) + V acting on m-component wave functions in Rn. We prove in generalization of…Felix Finster·Jun 14, 1996SaveLearn
Removal of the resolvent-like energy dependence from interactions and invariant subspaces of a total HamiltonianThe spectral problem (A + V(z))ψ=zψ is considered where the main Hamiltonian A is a self-adjoint operator of sufficiently arbitrary nature. The perturbation V(z)=-B(A'-z)-1B* depends…A. K. Motovilov·Jun 12, 1996SaveLearn
An Introduction to K-theory and Cyclic CohomologyThese lecture notes contain an exposition of basic ideas of K-theory and cyclic cohomology. I begin with a list of examples of various situations in which the K-functor of Grothendieck appears…Jacek Brodzki·Jun 3, 1996SaveLearn
Topological Hilbert Nullstellensatz for Bergman SpacesThe results in the paper are related to the classification problem for invariant subspaces of multiplication operators in several variables. The main results consist of characterizations, in the two…Razvan Gelca·May 10, 1996SaveLearn
Two applications of free entropyUsing Voiculsecu's free entropy, it is shown that the free group factors L(Fn) lack property C of Popa and that they lack finite multiplicity abelian subalgebras. Property C is an assymptotic…Ken Dykema·May 8, 1996SaveLearn
Hilbert H*-modules and Hilbert modules over (non-self-adjoint) operator algebras -- a reference overview IIThe two reference lists contain 54/22 references of papers and preprints concerned with the theory and/or various applications of Hilbert modules over Hilbert *-algebras and over (non-self-adjoint)…Michael Frank·May 7, 1996SaveLearn
Hilbert C*-modules and related subjects - a guided reference overview IThe overview contains 450 references of books, chapters of monographs, papers, preprints and Ph.~D.~thesises which are concerned with the theory and/or various applications of Hilbert C*-modules. To…Michael Frank·May 7, 1996SaveLearn
The :ϕ44: quantum field theory, I. Wave operator, holomorphity and Wick kernelWith the help of the complex structure and the wave operator of the nonlinear classical Klein-Gordon equation with the interaction u44 we define the Wick kernel of the interacting quantum field…Edward P. Osipov·May 7, 1996SaveLearn
Diagonalizing operators over continuous fields of C*-algebrasIt is well known that in the commutative case, i.e. for A=C(X) being a commutative C*-algebra, compact selfadjoint operators acting on the Hilbert C*-module HA (= continuous families of such…V. M. Manuilov·May 4, 1996SaveLearn
R-diagonal pairs - a common approach to Haar unitaries and circular elementsIn the free probability theory of Voiculescu two of the most frequently used *-distributions are those of a Haar unitary and of a circular element. We define an R-diagonal pair as a generalization…Alexandru Nica, Roland Speicher·Apr 30, 1996SaveLearn
On the multiplication of free n-tuples of non-commutative random variablesLet a1,...,an, b1,...,bn be random variables in some (non-commutative) probability space, such that \a1, ..., an \ is free from \b1, ..., bn \. We show how the joint…Alexandru Nica, Roland Speicher·Apr 30, 1996SaveLearn
q-Gaussian processes: non-commutative and classical aspectsWe examine, for -1<q<1, q-Gaussian processes, i.e. families of operators (non-commutative random variables) Xt=at+at* -- where the at fulfill the q-commutation relations…Marek Bozejko, Burkhard Kummerer, Roland Speicher·Apr 30, 1996SaveLearn
Amenability for Fell BundlesGiven a Fell bundle , over a discrete group Γ, we construct its reduced cross sectional algebra C*r(), in analogy with the reduced crossed products defined for C*-dynamical systems. When…Ruy Exel·Apr 23, 1996SaveLearn
A Theory of DimensionIn which a theory of dimension related to the Jones index and based on the notion of conjugation is developed. An elementary proof of the additivity and multiplicativity of the dimension is given and…Roberto Longo, John E. Roberts·Apr 17, 1996SaveLearn
Compact Perturbations of Fredholm n-tuples IIThe paper contains examples of Fredholm n-tuples of operators that are of index 0 but cannot be perturbed by compact operators to n-tuples with exact Koszul complex.Razvan Gelca·Apr 10, 1996SaveLearn