Quantum tomography with wavelet transform in Banach space on homogeneous space

In this study the intimate connection is established between the Banach space wavelet reconstruction method on homogeneous spaces with both singular and nonsingular vacuum vectors, and some of the well known quantum tomographies, such as: Moyal-representation for a spin, discrete phase space tomography, tomography of a free particle, Homodyne tomography, phase space tomography and SU(1,1) tomography. And both the atomic decomposition and the Banach frame nature of these quantum tomographic examples are also revealed in details. Finally the connection between the wavelet formalism on Banach space and Q-function is discussed.     

Large deviations for the stochastic derivative Ginzburg-Landau equation with multiplicative noise

This paper first proves the existence of a unique mild solution to the stochastic derivative Ginzburg-Landau equation. The fixed point theorem for the corresponding truncated equation is used as the main tool. Since we restrict our study to the one-dimensional case, it is not necessary to introduce another Banach space and thus the estimates of the stochastic convolutions in the Banach space are avoided. Secondly, we also consider large deviations for the stochastic derivative Ginzburg-Landau equation perturbed by a small noise. Since the underlying space considered is Polish, using the weak convergence approach, we establish a large deviations principle by proving a Laplace principle.     

p Dissipative Operator

In this paper the authors prove that the generalized positive p selfadjoint (GPpS) operators in Banach space satisfy the generalized Schwarz inequality, solve the maximal dissipative extension representation of pp dissipative operators in Banach space by using the inequality and introducing the generalized indefinite inner product (GIIP) space, and apply the result to a certain type of Schrödinger operator.     

Exponential dichotomy of linear impulsive differential equations in a Banach space

The dichotomy of linear impulsive equations in a Banach space is investigated.     

Connection between Group Based Quantum Tomography and Wavelet Transform in Banach Spaces

The intimate connection between the Banach space wavelet reconstruction method for each unitary representation of a given group and some of well known quantum tomographies, such as: tomography of rotation group, Spinor tomography and tomography of Unitary group, is established. Also both the atomic decomposition and Banach frame nature of these quantum tomographic examples is revealed in details.     

Quasirepresentations of amenable groups: Unbounded tame quasirepresentations

Continuing the study of representations of amenable groups, we discuss a model case in which a (not necessarily bounded) Banach space quasirepresentation of an amenable group is close to an ordinary representation of the group in the same space.     

Stability of the general exponent of nonlinear impulsive differential equations in a Banach space

A theorem is proved which gurantees stability under small perturbations of the general exponent of impulsive nonlinear systems in a Banach space.     

Local relativistic invariant flows for quantum fields

For quantum fields with trigonometric interaction in arbitrary space dimension we construct a representation of the Lorentz group by automorphisms on a Banach space generated by the Weyl algebra.     

Convergence of general decompositions of exponential operators

A general theorem is proved concerning the convergence of decompositions of exponential operators in a Banach space (or normed space). As a corollary, the convergence of fractal decompositions is proved. The convergence of generalized. Trotter-like formulas is also shown to result from the general theorem.     

Scattering theory of the linear Boltzmann operator

In time dependent scattering theory we know three important examples: the wave equation around an obstacle, the Schrödinger and the Dirac equation with a scattering potential. In this paper another example from time dependent linear transport theory is added and considered in full detail. First the linear Boltzmann operator in certain Banach spaces is rigorously defined, and then the existence of the Møller operators is proved by use of the theorem of Cook-Jauch-Kuroda, that is generalized to the case of a Banach space.     

On structural stability for semiflows

Some results on structural stability which are known to hold for flows of a compact manifold are extended to semiflows of a Banach space.     

The simplex structure of the classical states of the quantum harmonic oscillator

It is shown that the convex set of classical states of the quantum harmonic oscillator is a simplex generated as the closed convex hull of the coherent states in the weak topology of the Banach space of trace class operators.     

On the representation of linear evolution operators

We give a proof that any two parameter evolution operator may be represented as a Kossakowski's dynamical semigroup in a suitable Banach space.     

Boundedness and stability of impulsively perturbed systems in a Banach space

We consider the influence of impulsive perturbations of a linear impulsive equation in a Banach space on the existence of bounded solutions and the exponential stability of the equation.     

Continuous Spectrum of Automorphism Groups and the Infraparticle Problem

This paper presents a general framework for a refined spectral analysis of a group of isometries acting on a Banach space, which extends the spectral theory of Arveson. The concept of a continuous Arveson spectrum is introduced and the corresponding spectral subspace is defined. The absolutely continuous and singular-continuous parts of this spectrum are specified. Conditions are given, in terms of the transposed action of the group of isometries, which guarantee that the pure-point and continuous subspaces span the entire Banach space. In the case of a unitarily implemented group of automorphisms, acting on a C*-algebra, relations between the continuous spectrum of the automorphisms and the spectrum of the implementing group of unitaries are found. The group of spacetime translation automorphisms in quantum field theory is analyzed in detail. In particular, it is shown that the structure of its continuous spectrum is relevant to the problem of existence of (infra-)particles in a given theory.     

Generalized Hermitian Algebras

We refer to the real Jordan Banach algebra of bounded Hermitian operators on a Hilbert space as a Hermitian algebra. In this paper we define and launch a study of a class of generalized Hermitian (GH) algebras. Among the examples of GH-algebras are ordered special Jordan algebras, JW-algebras, and AJW-algebras, but unlike these more restricted cases, a GH-algebra is not necessarily a Banach space and its lattice of projections is not necessarily complete. In this paper we develop the basic theory of GH-algebras, identify their unit intervals as effect algebras, and observe that their projection lattices are sigma-complete orthomodular lattices. We show that GH-algebras are spectral order-unit spaces and that they admit a substantial spectral theory. The second author was supported by Research and Development Support Agency under the contract No. APVV-0071-06, grant VEGA 2/0032/09 and Center of Excellence SAS, CEPI I/2/2005.     

Harmonic Oscillator in Characteristic p

We construct an irreducible representation of the canonical commutation relations by operators on a certain Banach space over a local field of characteristic p. The Carlitz polynomials forming the basis of the space are shown to be the counterparts of the Hermite functions for this situation. The analogues of coherent states are related to the Carlitz exponential.     

An analytic nonlinear representation of the Poincaré group

We prove in a constructive way the existence of an analytic nonlinear representation of the Poincaré group in a Banach space, the linear part of which is the massless representation with helicity +1 (or-1). Furthermore, this nonlinear representation is shown to be analytically unwquivalent to any unitary linear representation.     

On the integrability of representations of finite dimensional real Lie algebras

We give an integrability criterion for Lie algebra representations in a reflexive Banach space. Applications are given to skewsymmetric Lie algebra representations in Hilbert spaces and to essential skewadjointness of a sum of two skewadjoint operators.