672,525 research outputs found
The distillability problem revisited
An important open problem in quantum information theory is the question of
the existence of NPT bound entanglement. In the past years, little progress has
been made, mainly because of the lack of mathematical tools to address the
problem. (i) In an attempt to overcome this, we show how the distillability
problem can be reformulated as a special instance of the separability problem,
for which a large number of tools and techniques are available. (ii) Building
up to this we also show how the problem can be formulated as a Schmidt number
problem. (iii) A numerical method for detecting distillability is presented and
strong evidence is given that all 1-copy undistillable Werner states are also
4-copy undistillable. (iv) The same method is used to estimate the volume of
distillable states, and the results suggest that bound entanglement is
primarily a phenomenon found in low dimensional quantum systems. (v) Finally, a
set of one parameter states is presented which we conjecture to exhibit all
forms of distillability.Comment: Several corrections, main results unchange
Ordered Rings and Fields
We introduce ordered rings and fields following Artin-Schreier’s approach using positive cones. We show that such orderings coincide with total order relations and give examples of ordered (and non ordered) rings and fields. In particular we show that polynomial rings can be ordered in (at least) two different ways [8, 5, 4, 9]. This is the continuation of the development of algebraic hierarchy in Mizar [2, 3].Schwarzweller Christoph - Institute of Informatics, University of Gdansk, Gdansk, PolandGrzegorz Bancerek. The fundamental properties of natural numbers. Formalized Mathematics, 1(1):41-46, 1990.Adam Grabowski, Artur Korniłowicz, and Adam Naumowicz. Four decades of Mizar. Journal of Automated Reasoning, 55(3):191-198, 2015.Adam Grabowski, Artur Korniłowicz, and Christoph Schwarzweller. On algebraic hierarchies in mathematical repository of Mizar. In M. Ganzha, L. Maciaszek, and M. Paprzycki, editors, Proceedings of the 2016 Federated Conference on Computer Science and Information Systems (FedCSIS), volume 8 of Annals of Computer Science and Information Systems, pages 363-371, 2016.Nathan Jacobson. Lecture Notes in Abstract Algebra, III. Theory of Fields and Galois Theory. Springer-Verlag, 1964.Manfred Knebusch and Claus Scheiderer. Einf¨uhrung in die reelle Algebra. Vieweg-Verlag, 1989.Andrzej Kondracki. Basic properties of rational numbers. Formalized Mathematics, 1(5): 841-845, 1990.Eugeniusz Kusak, Wojciech Leonczuk, and Michał Muzalewski. Abelian groups, fields and vector spaces. Formalized Mathematics, 1(2):335-342, 1990.Alexander Prestel. Lectures on Formally Real Fields. Springer-Verlag, 1984.Knut Radbruch. Geordnete K¨orper. Lecture Notes, University of Kaiserslautern, Germany, 1991.Michał J. Trybulec. Integers. Formalized Mathematics, 1(3):501-505, 1990
Thermodynamic Limit in Statistical Physics
The thermodynamic limit in statistical thermodynamics of many-particle
systems is an important but often overlooked issue in the various applied
studies of condensed matter physics. To settle this issue, we review tersely
the past and present disposition of thermodynamic limiting procedure in the
structure of the contemporary statistical mechanics and our current
understanding of this problem. We pick out the ingenious approach by N. N.
Bogoliubov, who developed a general formalism for establishing of the limiting
distribution functions in the form of formal series in powers of the density.
In that study he outlined the method of justification of the thermodynamic
limit when he derived the generalized Boltzmann equations. To enrich and to
weave our discussion, we take this opportunity to give a brief survey of the
closely related problems, such as the equipartition of energy and the
equivalence and nonequivalence of statistical ensembles. The validity of the
equipartition of energy permits one to decide what are the boundaries of
applicability of statistical mechanics. The major aim of this work is to
provide a better qualitative understanding of the physical significance of the
thermodynamic limit in modern statistical physics of the infinite and "small"
many-particle systems.Comment: 28 pages, Refs.180. arXiv admin note: text overlap with
arXiv:1011.2981, arXiv:0812.0943 by other author
A Survey on Continuous Time Computations
We provide an overview of theories of continuous time computation. These
theories allow us to understand both the hardness of questions related to
continuous time dynamical systems and the computational power of continuous
time analog models. We survey the existing models, summarizing results, and
point to relevant references in the literature
On a Perceived Expressive Inadequacy of Principia Mathematica
This paper deploys a Cantor-style diagonal argument which indicates that there is more possible mathematical content than there are propositional functions in Russell and Whitehead's Principia Mathematica and similar formal systems. This technical result raises a historical question: "How did Russell, who was himself an expert in diagonal arguments, not see this coming?" It turns out that answering this question requires an appreciation of Russell's understanding of what logic is, and how he construed the relationship between logic and Principia Mathematica
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