10,176 research outputs found
A compositional coalgebraic model of a fragment of fusion calculus
This work is a further step in exploring the labelled transitions and bisimulations of fusion calculi. We follow the approach developed by Turi and Plotkin for lifting transition systems with a syntactic structure to bialgebras and, thus, we provide a compositional model of the fusion calculus with explicit fusions. In such a model, the bisimilarity relation induced by the unique morphism to the final coalgebra coincides with fusion hyperequivalence and it is a congruence with respect to the operations of the calculus. The key novelty in our work is to give an account of explicit fusions through labelled transitions. In this short essay, we focus on a fragment of the fusion calculus without recursion and replication
A compositional coalgebraic model of a fragment of fusion calculus
This work is a further step in exploring the labelled transitions and bisimulations of fusion calculi. We follow the approach developed by Turi and Plotkin for lifting transition systems with a syntactic structure to bialgebras and, thus, we provide a compositional model of the fusion calculus with explicit fusions. In such a model, the bisimilarity relation induced by the unique morphism to the final coalgebra coincides with fusion hyperequivalence and it is a congruence with respect to the operations of the calculus. The key novelty in our work is to give an account of explicit fusions through labelled transitions. In this short essay, we focus on a fragment of the fusion calculus without recursion and replication
The Novel ''Controlled Intermediate Nuclear Fusion'' and its Possible Industrial Realization as Predicted by Hadronic Mechanics and Chemistry
In this note, we propose, apparently for the first time, a new type of
controlled nuclear fusion called "intermediate" because occurring at energies
intermediate between those of the ''cold'' and ''hot'' fusions, and propose a
specific industrial realization. For this purpose: 1) We show that known
limitations of quantum mechanics, quantum chemistry and special relativity
cause excessive departures from the conditions occurring for all controlled
fusions; 2) We outline the covering hadronic mechanics, hadronic chemistry and
isorelativity specifically conceived, constructed and verified during the past
two decades for new cleans energies and fuels; 3) We identify seven physical
laws predicted by the latter disciplines that have to be verified by all
controlled nuclear fusions to occur; 4) We review the industrial research
conducted to date in the selection of the most promising engineering
realization as well as optimization of said seven laws; and 5) We propose with
construction details a specific {\it hadronic reactor} (patented and
international patents pending), consisting of actual equipment specifically
intended for the possible industrial production of the clean energy released by
representative cases of controlled intermediate fusions for independent
scrutiny by interested colleagues.Comment: 32 pages, 5 figures. Journal of Applied Sciences, in pres
Fusion Algebras of Logarithmic Minimal Models
We present explicit conjectures for the chiral fusion algebras of the
logarithmic minimal models LM(p,p') considering Virasoro representations with
no enlarged or extended symmetry algebra. The generators of fusion are
countably infinite in number but the ensuing fusion rules are quasi-rational in
the sense that the fusion of a finite number of representations decomposes into
a finite direct sum of representations. The fusion rules are commutative,
associative and exhibit an sl(2) structure but require so-called Kac
representations which are reducible yet indecomposable representations of rank
1. In particular, the identity of the fundamental fusion algebra is in general
a reducible yet indecomposable Kac representation of rank 1. We make detailed
comparisons of our fusion rules with the results of Gaberdiel and Kausch for
p=1 and with Eberle and Flohr for (p,p')=(2,5) corresponding to the logarithmic
Yang-Lee model. In the latter case, we confirm the appearance of indecomposable
representations of rank 3. We also find that closure of a fundamental fusion
algebra is achieved without the introduction of indecomposable representations
of rank higher than 3. The conjectured fusion rules are supported, within our
lattice approach, by extensive numerical studies of the associated integrable
lattice models. Details of our lattice findings and numerical results will be
presented elsewhere. The agreement of our fusion rules with the previous fusion
rules lends considerable support for the identification of the logarithmic
minimal models LM(p,p') with the augmented c_{p,p'} (minimal) models defined
algebraically.Comment: 22 pages, v2: comments adde
The su(2)_{-1/2} WZW model and the beta-gamma system
The bosonic beta-gamma ghost system has long been used in formal
constructions of conformal field theory. It has become important in its own
right in the last few years, as a building block of field theory approaches to
disordered systems, and as a simple representative -- due in part to its
underlying su(2)_{-1/2} structure -- of non-unitary conformal field theories.
We provide in this paper the first complete, physical, analysis of this
beta-gamma system, and uncover a number of striking features. We show in
particular that the spectrum involves an infinite number of fields with
arbitrarily large negative dimensions. These fields have their origin in a
twisted sector of the theory, and have a direct relationship with spectrally
flowed representations in the underlying su(2)_{-1/2} theory. We discuss the
spectral flow in the context of the operator algebra and fusion rules, and
provide a re-interpretation of the modular invariant consistent with the
spectrum.Comment: 33 pages, 1 figure, LaTeX, v2: minor revision, references adde
Comments on nonunitary conformal field theories
As is well-known, nonunitary RCFTs are distinguished from unitary ones in a
number of ways, two of which are that the vacuum 0 doesn't have minimal
conformal weight, and that the vacuum column of the modular S matrix isn't
positive. However there is another primary field, call it o, which has minimal
weight and has positive S column. We find that often there is a precise and
useful relationship, which we call the Galois shuffle, between primary o and
the vacuum; among other things this can explain why (like the vacuum) its
multiplicity in the full RCFT should be 1. As examples we consider the minimal
WSU(N) models. We conclude with some comments on fractional level admissible
representations of affine algebras. As an immediate consequence of our
analysis, we get the classification of an infinite family of nonunitary WSU(3)
minimal models in the bulk.Comment: 24 page
Null vectors of the algebra
Using the fusion principle of Bauer et al. we give explicit expressions for
some null vectors in the highest weight representations of the \bc algebra in
two different forms. These null vectors are the generalization of the Virasoro
ones described by Benoit and Saint-Aubin and analogues of the ones
constructed by Bowcock and Watts. We find connection between quantum Toda
models and the fusion method.Comment: 8 pages, LaTeX, ITP Budapest 50
N-point and higher-genus osp(1|2) fusion
We study affine osp(1|2) fusion, the fusion in osp(1|2) conformal field
theory, for example. Higher-point and higher-genus fusion is discussed. The
fusion multiplicities are characterized as discretized volumes of certain
convex polytopes, and are written explicitly as multiple sums measuring those
volumes. We extend recent methods developed to treat affine su(2) fusion. They
are based on the concept of generalized Berenstein-Zelevinsky triangles and
virtual couplings. Higher-point tensor products of finite-dimensional
irreducible osp(1|2) representations are also considered. The associated
multiplicities are computed and written as multiple sums.Comment: 17 pages, LaTe
Boundary states for WZW models
The boundary states for a certain class of WZW models are determined. The
models include all modular invariants that are associated to a symmetry of the
unextended Dynkin diagram. Explicit formulae for the boundary state
coefficients are given in each case, and a number of properties of the
corresponding NIM-reps are derived.Comment: 34 pages, harvmac (b), 4 eps-figures. One reference added; some minor
typos, as well as the embedding into , are correcte
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