1,622 research outputs found
Non-disturbing quantum measurements
We consider pairs of quantum observables (POVMs) and analyze the relation
between the notions of non-disturbance, joint measurability and commutativity.
We specify conditions under which these properties coincide or
differ---depending for instance on the interplay between the number of outcomes
and the Hilbert space dimension or on algebraic properties of the effect
operators. We also show that (non-)disturbance is in general not a symmetric
relation and that it can be decided and quantified by means of a semidefinite
program.Comment: Minor corrections in v
Meta SOS - A Maude Based SOS Meta-Theory Framework
Meta SOS is a software framework designed to integrate the results from the
meta-theory of structural operational semantics (SOS). These results include
deriving semantic properties of language constructs just by syntactically
analyzing their rule-based definition, as well as automatically deriving sound
and ground-complete axiomatizations for languages, when considering a notion of
behavioural equivalence. This paper describes the Meta SOS framework by
blending aspects from the meta-theory of SOS, details on their implementation
in Maude, and running examples.Comment: In Proceedings EXPRESS/SOS 2013, arXiv:1307.690
No-signaling, dynamical independence, and the local observability principle
Within a general operational framework I show that a-causality at a distance
of "local actions" (the so-called "no-signaling") is a direct consequence of
commutativity of local transformations, i.e. of dynamical independence. On the
other hand, the tensor product of Quantum Mechanics is not just a consequence
of such dynamical independence, but needs in addition the Local Observability
Principle.Comment: Presented at the conference "Theory and Technology in Quantum
Information, Communication, Computation and Cryptography", Trieste SISSA,
June 2006. Submitted to J. Phys. A. Math. Ge
Hamiltonian Dynamics, Classical R-matrices and Isomonodromic Deformations
The Hamiltonian approach to the theory of dual isomonodromic deformations is
developed within the framework of rational classical R-matrix structures on
loop algebras. Particular solutions to the isomonodromic deformation equations
appearing in the computation of correlation functions in integrable quantum
field theory models are constructed through the Riemann-Hilbert problem method.
The corresponding -functions are shown to be given by the Fredholm
determinant of a special class of integral operators.Comment: LaTeX 13pgs (requires lamuphys.sty). Text of talk given at workshop:
Supersymmetric and Integrable Systems, University of Illinois, Chicago
Circle, June 12-14, 1997. To appear in: Springer Lecture notes in Physic
A note on systems with ordinary and impulsive controls
We investigate an everywhere defined notion of solution for control systems
whose dynamics depend nonlinearly on the control and state and are
affine in the time derivative For this reason, the input which
is allowed to be Lebesgue integrable, is called impulsive, while a second,
bounded measurable control is denominated ordinary. The proposed notion of
solution is derived from a topological (non-metric) characterization of a
former concept of solution which was given in the case when the drift is
-independent. Existence, uniqueness and representation of the solution are
studied, and a close analysis of effects of (possibly infinitely many)
discontinuities on a null set is performed as well.Comment: Article published in IMA J. Math. Control Infor
Non-linear Quantization of Integrable Classical Systems
It is demonstrated that the so-called "unavoidable quantum anomalies" can be
avoided in the farmework of a special non-linear quantization scheme. A simple
example is discussed in detail.Comment: LaTeX, 14 p
- …