Search results for " space"
showing 10 items of 4562 documents
Weak commutation relations of unbounded operators and applications
2011
Four possible definitions of the commutation relation $[S,T]=\Id$ of two closable unbounded operators $S,T$ are compared. The {\em weak} sense of this commutator is given in terms of the inner product of the Hilbert space $\H$ where the operators act. Some consequences on the existence of eigenvectors of two number-like operators are derived and the partial O*-algebra generated by $S,T$ is studied. Some applications are also considered.
About Compactness of Faddeev Integral Equations for Three Charged Particles
1999
Momentum space three-body integral equations of the Faddeev type can not be used for Coulomb-like potentials, for energies above the breakup threshold. The reason is the occurrence of singularities in their kernels which destroy the compactness properties known to exist for purely short-range interactions. Using the rigorously equivalent formulation in terms of an effective-two- body theory, we prove that the nondiagonal kernels occurring therein possess on and off the energy shell only integrable singularities, provided all three particles have charges of the same sign (ie., only repulsive Coulomb interactions). In contrast, if some of the charges have opposite signs the nondiagonal kernel…
A comparison theorem for the mean exit time from a domain in a K�hler manifold
1992
Let M be a Kahler manifold with Ricci and antiholomorphic Ricci curvature bounded from below. Let ω be a domain in M with some bounds on the mean and JN-mean curvatures of its boundary ∂ω. The main result of this paper is a comparison theorem between the Mean Exit Time function defined on ω and the Mean Exit Time from a geodesic ball of the complex projective space ℂℙ n (λ) which involves a characterization of the geodesic balls among the domain ω. In order to achieve this, we prove a comparison theorem for the mean curvatures of hypersurfaces parallel to the boundary of ω, using the Index Lemma for Submanifolds.
Quantum like modelling of decision making: quantifying uncertainty with the aid of the Heisenberg-Robertson inequality
2018
This paper contributes to quantum-like modeling of decision making (DM) under uncertainty through application of Heisenberg’s uncertainty principle (in the form of the Robertson inequality). In this paper we apply this instrument to quantify uncertainty in DM performed by quantum-like agents. As an example, we apply the Heisenberg uncertainty principle to the determination of mutual interrelation of uncertainties for “incompatible questions” used to be asked in political opinion pools. We also consider the problem of representation of decision problems, e.g., in the form of questions, by Hermitian operators, commuting and noncommuting, corresponding to compatible and incompatible questions …
Competencias profesionales y empleo en el futuro periodista: el caso de los estudiantes de Periodismo de la Universidad Cardenal Herrera-CEU
2010
Presentamos un trabajo de investigacion cientifica enfocado en dos aspectos: la adquisicion de competencias profesionales en los alumnos de la licenciatura de Periodismo de la Universidad Cardenal Herrera-CEU y la importancia que otorgan a diferentes aspectos de un empleo. Este ultimo aspecto, partiendo del Informe Reflex de ANECA “El profesional flexible en la Sociedad del Conocimiento” establecemos una comparativa entre los resultados alli obtenidos y el caso particular de los alumnos de Periodismo de la Cardenal Herrera-CEU. Para descubrir estos aspectos presentamos un trabajo empirico para conocer en que medida los alumnos de ultimo curso de la licenciatura de la Universidad Cardenal He…
Spatial Competition in Quality
2011
We develop a model of vertical innovation in which firms incur a market entry cost and position themselves in the quality space. Once established, firms compete monopolistically, selling to consumers with heterogeneous tastes for quality. We establish the general existence and conditional uniqueness of the pricing game in such vertically differentiated markets with a potentially large number of active firms. Turning to firms’ entry decisions, exogenously growing productivities induce firms to enter the market sequentially at the top end of the quality spectrum. We spell out the conditions under which the entry problem is replicated over time so that each new entrant improves incumbent quali…
A note on Fréchet and approximate subdifferentials of composite functions
1994
The aim of this note is to present in the reflexive Banach space setting a natural and simple proof of the formula of the approximate subdifferential of a composite function.
Comment on: A critical analysis of the internal logic in the Life-Space Assessment (LSA) composite score and suggested solutions
2016
Background:An individual’s ability to live independently is commonly measured in health research interested in identifying risk factors associated with disablement processes. In order to inform clinical practice, population research has attempted to identify the contraction of “lived-space” by using various survey instruments.Problem:Studies assessing habitual movements over the environment with the Life-Space Assessment (LSA) survey instrument should carefully consider how the LSA Composite Score (LSA-CS) is computed. Until now, no publication has carefully delineated the assumptions guiding the internal logic used in the computation of the LSA-CS.Core argument:Because the internal logic o…
Una mañana en Oporto : apuntes de un viaje en la arquitectura de Álvaro Siza
2023
Per un architetto il viaggio è una impareggiabile occasione di studio, poiché permette di compiere una reale esperienza dello spazio, consente di valutare con i propri sensi ciò che altrimenti sarebbe sempre mediato dal disegno, dalla fotografia, dai testi o da altre rappresentazioni. La visita ad alcune architetture di Álvaro Siza, diviene occasione per una analisi critica e consente di estrarre alcune lezioni sul rapporto con i luoghi, sui caratteri dello spazio, sulla materialità, sull’impiego della luce, sul valore del dettaglio.
Creativity in Conceptual Spaces
2014
The main aim of this paper is contributing to what in the last few years has been known as computational creativity. This will be done by showing the relevance of a particular mathematical representation of G"ardenfors's conceptual spaces to the problem of modelling a phenomenon which plays a central role in producing novel and fruitful representations of perceptual patterns: analogy.