6,418 research outputs found
Logics for Unranked Trees: An Overview
Labeled unranked trees are used as a model of XML documents, and logical
languages for them have been studied actively over the past several years. Such
logics have different purposes: some are better suited for extracting data,
some for expressing navigational properties, and some make it easy to relate
complex properties of trees to the existence of tree automata for those
properties. Furthermore, logics differ significantly in their model-checking
properties, their automata models, and their behavior on ordered and unordered
trees. In this paper we present a survey of logics for unranked trees
Fingerprints of heavy scales in electroweak effective Lagrangians
The couplings of the electroweak effective theory contain information on the
heavy-mass scales which are no-longer present in the low-energy Lagrangian. We
build a general effective Lagrangian, implementing the electroweak chiral
symmetry breaking , which couples the
known particle fields to heavier states with bosonic quantum numbers
and . We consider colour-singlet heavy fields that are in
singlet or triplet representations of the electroweak group. Integrating out
these heavy scales, we analyze the pattern of low-energy couplings among the
light fields which are generated by the massive states. We adopt a generic
non-linear realization of the electroweak symmetry breaking with a singlet
Higgs, without making any assumption about its possible doublet structure.
Special attention is given to the different possible descriptions of massive
spin-1 fields and the differences arising from naive implementations of these
formalisms, showing their full equivalence once a proper short-distance
behaviour is required.Comment: 57 pages, 1 pdf figure. Version published at JHE
From Color Glass to Color Dipoles in high-energy onium--onium scattering
Within the Color Glass formalism, we construct the wavefunction of a high
energy onium in the BFKL and large-N_c approximations, and demonstrate the
equivalence with the corresponding result in the Color Dipole picture. We
propose a simple factorization formula for the elastic scattering between two
non-saturated ``color glasses'' in the center-of-mass frame. This is valid up
to energies which are high enough to allow for a study of the onset of
unitarization via multiple pomeron exchanges. When applied to the high energy
onium-onium scattering, this formula reduces to the Glauber-like scattering
between two systems of dipoles, in complete agreement with the dipole picture.Comment: 35 pages, 2 figure
Mesoscopic Full Counting Statistics and Exclusion models
We calculate the distribution of current fluctuations in two simple exclusion
models. Although these models are classical, we recover even for small systems
such as a simple or a double barrier, the same distibution of current as given
by traditionnal formalisms for quantum mesoscopic conductors. Due to their
simplicity, the full counting statistics in exclusion models can be reduced to
the calculation of the largest eigenvalue of a matrix, the size of which is the
number of internal configurations of the system. As examples, we derive the
shot noise power and higher order statistics of current fluctuations (skewness,
full counting statistics, ....) of various conductors, including multiple
barriers, diffusive islands between tunnel barriers and diffusive media. A
special attention is dedicated to the third cumulant, which experimental
measurability has been demonstrated lately.Comment: Submitted to Eur. Phys. J.
Expressiveness and Completeness in Abstraction
We study two notions of expressiveness, which have appeared in abstraction
theory for model checking, and find them incomparable in general. In
particular, we show that according to the most widely used notion, the class of
Kripke Modal Transition Systems is strictly less expressive than the class of
Generalised Kripke Modal Transition Systems (a generalised variant of Kripke
Modal Transition Systems equipped with hypertransitions). Furthermore, we
investigate the ability of an abstraction framework to prove a formula with a
finite abstract model, a property known as completeness. We address the issue
of completeness from a general perspective: the way it depends on certain
abstraction parameters, as well as its relationship with expressiveness.Comment: In Proceedings EXPRESS/SOS 2012, arXiv:1208.244
Properties of ABA+ for Non-Monotonic Reasoning
We investigate properties of ABA+, a formalism that extends the well studied
structured argumentation formalism Assumption-Based Argumentation (ABA) with a
preference handling mechanism. In particular, we establish desirable properties
that ABA+ semantics exhibit. These pave way to the satisfaction by ABA+ of some
(arguably) desirable principles of preference handling in argumentation and
nonmonotonic reasoning, as well as non-monotonic inference properties of ABA+
under various semantics.Comment: This is a revised version of the paper presented at the worksho
Wavelets techniques for pointwise anti-Holderian irregularity
In this paper, we introduce a notion of weak pointwise Holder regularity,
starting from the de nition of the pointwise anti-Holder irregularity. Using
this concept, a weak spectrum of singularities can be de ned as for the usual
pointwise Holder regularity. We build a class of wavelet series satisfying the
multifractal formalism and thus show the optimality of the upper bound. We also
show that the weak spectrum of singularities is disconnected from the casual
one (denoted here strong spectrum of singularities) by exhibiting a
multifractal function made of Davenport series whose weak spectrum di ers from
the strong one
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