318 research outputs found
Tamari Lattices and the symmetric Thompson monoid
We investigate the connection between Tamari lattices and the Thompson group
F, summarized in the fact that F is a group of fractions for a certain monoid
F+sym whose Cayley graph includes all Tamari lattices. Under this
correspondence, the Tamari lattice operations are the counterparts of the least
common multiple and greatest common divisor operations in F+sym. As an
application, we show that, for every n, there exists a length l chain in the
nth Tamari lattice whose endpoints are at distance at most 12l/n.Comment: 35page
Lattice Point Generating Functions and Symmetric Cones
We show that a recent identity of Beck-Gessel-Lee-Savage on the generating
function of symmetrically contrained compositions of integers generalizes
naturally to a family of convex polyhedral cones that are invariant under the
action of a finite reflection group. We obtain general expressions for the
multivariate generating functions of such cones, and work out the specific
cases of a symmetry group of type A (previously known) and types B and D (new).
We obtain several applications of the special cases in type B, including
identities involving permutation statistics and lecture hall partitions.Comment: 19 page
Signatures of partition functions and their complexity reduction through the KP II equation
A statistical amoeba arises from a real-valued partition function when the
positivity condition for pre-exponential terms is relaxed, and families of
signatures are taken into account. This notion lets us explore special types of
constraints when we focus on those signatures that preserve particular
properties. Specifically, we look at sums of determinantal type, and main
attention is paid to a distinguished class of soliton solutions of the
Kadomtsev-Petviashvili (KP) II equation. A characterization of the signatures
preserving the determinantal form, as well as the signatures compatible with
the KP II equation, is provided: both of them are reduced to choices of signs
for columns and rows of a coefficient matrix, and they satisfy the whole KP
hierarchy. Interpretations in term of information-theoretic properties,
geometric characteristics, and the relation with tropical limits are discussed.Comment: 42 pages, 11 figures. Section 7.1 has been added, the organization of
the paper has been change
Superfield Description of a Self-Dual Supergravity a la MacDowell-Mansouri
Using MacDowell-Mansouri theory, in this work, we investigate a superfield
description of the self-dual supergravity a la Ashtekar. We find that in order
to reproduce previous results on supersymmetric Ashtekar formalism, it is
necessary to properly combine the supersymmetric field-strength in the
Lagrangian. We extend our procedure to the case of supersymmetric Ashtekar
formalism in eight dimensions.Comment: 19 pages, Latex; section 6 improve
Towards an Ashtekar formalism in eight dimensions
We investigate the possibility of extending the Ashtekar theory to eight
dimensions. Our approach relies on two notions: the octonionic structure and
the MacDowell-Mansouri formalism generalized to a spacetime of signature 1+7.
The key mathematical tool for our construction is the self-dual (antiself-dual)
four-rank fully antisymmetric octonionic tensor. Our results may be of
particular interest in connection with a possible formulation of M-theory via
matroid theory.Comment: 15 pages, Latex, minor changes, to appear in Class. Quantum Gra
Hamiltonian Noether theorem for gauge systems and two time physics
The Noether theorem for Hamiltonian constrained systems is revisited. In
particular, our review presents a novel method to show that the gauge
transformations are generated by the conserved quantities associated with the
first class constraints. We apply our results to the relativistic point
particle, to the Friedberg et al. model and, with special emphasis, to two time
physics.Comment: 20 pages, Latex, references added, the "massless" sense of (87) is
clarifie
A longitudinal study of perceived health during pregnancy: antecedents and outcomes
Perceived health was studied longitudinally in a sample of 364 nulliparous women. Psychosocial, contextual, and biomedical factors were taken into account to predict medically relevant versus benign symptoms which were then used to predict perceived health over time. The results of structural equation modeling showed that pregnancy adjustment and medically relevant symptoms which were affected by social support, perceived stress, and negative affect predicted later perceived health. The outcomes of perceived health were examined during the third trimester in terms of medical care utilization and emergency room visits. Perceived health solely accounted for medical care utilization, while emergency room visits were accounted by medical care utilization and perceived stress
Job strain and the risk of severe asthma exacerbations : a meta-analysis of individual-participant data from 100 000 European men and women
Peer reviewe
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