Search results for "Unitary state"
showing 10 items of 133 documents
De nuevo sobre la intensificación pragmática : revisión y propuesta
2021
Este artículo presenta una propuesta de caracterización de la intensificación desde una perspectiva pragmática con el objetivo de contribuir al establecimiento de una definición completa, delimitada y unitaria del fenómeno, que permita reconocer y discriminar los usos intensificaciones de otras categorías cercanas. Para ello, se revisan las principales aportaciones previas al estudio del fenómeno: desde las más extendidas, de carácter gramatical y semántico, a las más recientes de naturaleza pragmática.
 Se propone, por un lado, una explicación cognitiva y metarrepresentacional que define la intensificación como el intento lingüístico de un hablante por modificar los supuestos que le a…
Intra-party heterogeneity in policy preferences and its effect on issue salience: Developing and applying a measure based on elite survey data
2017
Quantitative research on party politics often has to assume that parties are unitary actors with homogeneous policy preferences simply because intra-party heterogeneity is difficult to measure. This article proposes a measure of preference heterogeneity based on surveys of party elites. We draw on Comparative Candidates Survey (CCS) data from 28 elections in 21 developed democracies to quantify intra-party heterogeneity and validate this measure. The usefulness of the measure is demonstrated by studying the effects of intra-party heterogeneity on issue salience. We find support for the hypothesis that heterogeneity regarding a policy issue tends to be negatively associated with the emphasi…
Dynamically generated resonances from the vector octet-baryon octet interaction
2010
We study the interaction of vector mesons with the octet of stable baryons in the framework of the local hidden gauge formalism using a coupled-channels unitary approach. We examine the scattering amplitudes and their poles, which can be associated to known J(P) = 1/2(-), 3/2(-) baryon resonances, in some cases, or give predictions in other ones. The formalism employed produces doublets of degenerate J(P) = 1/2(-), 3/2(-) states, a pattern which is observed experimentally in several cases. The findings of this work should also be useful to guide present experimental programs searching for new resonances, in particular in the strange sector where the current information is very poor.
Operators intertwining with isometries and Brownian parts of 2-isometries
2016
Abstract For two operators A and T ( A ≥ 0 ) on a Hilbert space H satisfying T ⁎ A T = A and the A-regularity condition A T = A 1 / 2 T A 1 / 2 we study the subspace N ( A − A 2 ) in connection with N ( A T − T A ) , for T belonging to different classes. Our results generalize those due to C. Kubrusly concerning the case when T is a contraction and A = S T is the asymptotic limit of T. Also, the particular case of a 2-isometry in the sense of S. Richter as well as J. Agler and M. Stankus is considered. For such operators, under the same regularity condition we completely describe the reducing Brownian unitary and isometric parts, as well as the invariant Brownian isometric part. Some exampl…
Generalized inverses and similarity to partial isometries
2010
Abstract We obtain some results related to the problems of Badea and Mbekhta (2005) [1] concerning the similarity to partial isometries using the generalized inverses. Especially, we involve the Moore–Penrose inverses. Also a characterization for such a similarity is given in the terms of dilations similar to unitary operators, which leads to a new criterion for the similarity to an isometry and to a quasinormal partial isometry.
The hermeneutics of sport: limits and conditions of possibility of our understandings of sport
2016
AbstractIn this paper, linguistic-analytic philosophy has been identified as the dominant methodology in the philosophy of sport. The hermeneutics of sport is contrasted with linguistic-analytic philosophy by analyzing Heidegger’s view of Truth. In doing so, two views of philosophy are compared: ontology or description. Sport hermeneutics’ task has to do with description. Hermeneutical explanations of sport attempt to describe the facticity of sport. Such a facticity is formed by three moments: embodiment, capabilities, and tradition. They are not components of sport that can be identified as essential components but rather, they are identifiable only for analytic purposes. These three abov…
System-environment correlations and Markovian embedding of quantum non-Markovian dynamics
2018
We study the dynamics of a quantum system whose interaction with an environment is described by a collision model, i.e. the open dynamics is modelled through sequences of unitary interactions between the system and the individual constituents of the environment, termed "ancillas", which are subsequently traced out. In this setting non-Markovianity is introduced by allowing for additional unitary interactions between the ancillas. For this model, we identify the relevant system-environment correlations that lead to a non-Markovian evolution. Through an equivalent picture of the open dynamics, we introduce the notion of "memory depth" where these correlations are established between the syste…
Unitary Approach to Vibrational Spectra of Tetrahedral Molecules: Generalized Infrared Intensity Model.
1997
International audience; In this paper we further extend a previous formalism, the construction of a dipole function adapted to tetrahedral molecules. The extension is based on an algebraic construction of symmetrized tensor operators through unitary algebra and point group symmetry. We prove that this generalization allows us to find the particular formalism that has been established and satisfactorily tested in a previous paper (C. Leroy et al., J. Mol. Spectrosc. 175, 289–295 (1996)).
Two, three, many body systems involving mesons
2011
In this talk we show recent developments on few body systems involving mesons. We report on an approach to Faddeev equations using chiral unitary dynamics, where an explicit cancellation of the two body off shell amplitude with three body forces stemming from the same chiral Lagrangians takes place. This removal of the unphysical off shell part of the amplitudes is most welcome and renders the approach unambiguous, showing that only on shell two body amplitudes need to be used. Within this approach, systems of two mesons and one baryon are studied, reproducing properties of the low lying $1/2^+$ states. On the other hand we also report on multirho and $K^*$ multirho states which can be asso…
Equivalence betweenXYand dimerized models
2010
The spin-$1/2$ chain with $\mathit{XY}$ anisotropic coupling in the plane and the $\mathit{XX}$ isotropic dimerized chain are shown to be equivalent in the bulk. For finite systems, we prove that the equivalence is exact in given parity sectors, after taking care of the precise boundary conditions. The proof is given constructively by finding unitary transformations that map the models onto each other. Moreover, we considerably generalized our mapping and showed that even in the case of fully site-dependent couplings the $\mathit{XY}$ chain can be mapped onto an $\mathit{XX}$ model. This result has potential application in the study of disordered systems.