6,029 research outputs found
Partially ordered pattern algebras
A partial order ≤ on a set A induces a partition of each power An into "patterns" in a natural way. An operation on A is called a ≤-pattern operation if its restriction to each pattern is a projection. We examine functional completeness of algebras with ≤-pattern fundamental operations
Finite closed coverings of compact quantum spaces
We show that a projective space P^\infty(Z/2) endowed with the Alexandrov
topology is a classifying space for finite closed coverings of compact quantum
spaces in the sense that any such a covering is functorially equivalent to a
sheaf over this projective space. In technical terms, we prove that the
category of finitely supported flabby sheaves of algebras is equivalent to the
category of algebras with a finite set of ideals that intersect to zero and
generate a distributive lattice. In particular, the Gelfand transform allows us
to view finite closed coverings of compact Hausdorff spaces as flabby sheaves
of commutative C*-algebras over P^\infty(Z/2).Comment: 26 pages, the Teoplitz quantum projective space removed to another
paper. This is the third version which differs from the second one by fine
tuning and removal of typo
Homology of generalized partition posets
We define a poset of partitions associated to an operad. We prove that the
operad is Koszul if and only if the poset is Cohen-Macaulay.
In one hand, this characterisation allows us to compute the homology of the
poset. This homology is given by the Koszul dual operad. On the other hand, we
get new methods for proving that an operad is Koszul.Comment: Final version. To appear in JPA
Boolean Coverings of Quantum Observable Structure: A Setting for an Abstract Differential Geometric Mechanism
We develop the idea of employing localization systems of Boolean coverings,
associated with measurement situations, in order to comprehend structures of
Quantum Observables. In this manner, Boolean domain observables constitute
structure sheaves of coordinatization coefficients in the attempt to probe the
Quantum world. Interpretational aspects of the proposed scheme are discussed
with respect to a functorial formulation of information exchange, as well as,
quantum logical considerations. Finally, the sheaf theoretical construction
suggests an opearationally intuitive method to develop differential geometric
concepts in the quantum regime.Comment: 25 pages, Late
Actor Network Procedures as Psi-calculi for Security Ceremonies
The actor network procedures of Pavlovic and Meadows are a recent graphical
formalism developed for describing security ceremonies and for reasoning about
their security properties. The present work studies the relations of the actor
network procedures (ANP) to the recent psi-calculi framework. Psi-calculi is a
parametric formalism where calculi like spi- or applied-pi are found as
instances. Psi-calculi are operational and largely non-graphical, but have
strong foundation based on the theory of nominal sets and process algebras. One
purpose of the present work is to give a semantics to ANP through psi-calculi.
Another aim was to give a graphical language for a psi-calculus instance for
security ceremonies. At the same time, this work provides more insight into the
details of the ANPs formalization and the graphical representation.Comment: In Proceedings GraMSec 2014, arXiv:1404.163
Gr\"obner methods for representations of combinatorial categories
Given a category C of a combinatorial nature, we study the following
fundamental question: how does the combinatorial behavior of C affect the
algebraic behavior of representations of C? We prove two general results. The
first gives a combinatorial criterion for representations of C to admit a
theory of Gr\"obner bases. From this, we obtain a criterion for noetherianity
of representations. The second gives a combinatorial criterion for a general
"rationality" result for Hilbert series of representations of C. This criterion
connects to the theory of formal languages, and makes essential use of results
on the generating functions of languages, such as the transfer-matrix method
and the Chomsky-Sch\"utzenberger theorem.
Our work is motivated by recent work in the literature on representations of
various specific categories. Our general criteria recover many of the results
on these categories that had been proved by ad hoc means, and often yield
cleaner proofs and stronger statements. For example: we give a new, more
robust, proof that FI-modules (originally introduced by Church-Ellenberg-Farb),
and a family of natural generalizations, are noetherian; we give an easy proof
of a generalization of the Lannes-Schwartz artinian conjecture from the study
of generic representation theory of finite fields; we significantly improve the
theory of -modules, introduced by Snowden in connection to syzygies of
Segre embeddings; and we establish fundamental properties of twisted
commutative algebras in positive characteristic.Comment: 41 pages; v2: Moved old Sections 3.4, 10, 11, 13.2 and connected text
to arxiv:1410.6054v1, Section 13.1 removed and will appear elsewhere; v3:
substantial revision and reorganization of section
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