2,177 research outputs found
On the shape of dark matter halos from MultiDark Planck simulations
The halo shape plays a central role in determining important observational
properties of the haloes such as mass, concentration and lensing
cross-sections. The triaxiality of lensing galaxy clusters has a substantial
impact on the distribution of the largest Einstein radii, while weak lensing
techniques are sensitive to the intrinsic halo ellipticity. In this work, we
provide scaling relations for the shapes of dark matter haloes as a function of
mass (peak height) and redshift over more than four orders of magnitude in halo
masses, namely from to M. We have
analysed four dark matter only simulations from the MultiDark cosmological
simulation suite with more than 56 billion particles within boxes of 4.0, 2.5,
1.0 and 0.4 Gpc size assuming \textit{Planck} cosmology. The dark
matter haloes have been identified in the simulations using the {\sc rockstar}
halo finder, which also determines the axis ratios in terms of the
diagonalization of the inertia tensor. In order to infer the shape for a
hypothetical halo of a given mass at a given redshift, we provide fitting
functions to the minor-to-major and intermediate-to-major axis ratios as a
function of the peak height.Comment: Accepted for publication in MNRAS (14 pages, 13 figures). The
ROCKSTAR outputs used in this paper are available at
https://www.cosmosim.org/cms/simulations/data
El cine y las potencias de lo engañoso. En torno a Die Marquise von O, de Éric Rohmer
En este artículo, reflexiono sobre la naturaleza de la imagen cinematográfica a partir del análisis de una de las películas de Éric Rohmer, Die Marquise von O, y los propios escritos teóricos del cineasta francés. Mi interpretación de la película se enmarca en una ejemplificación de lo que, para Rohmer, son las virtualidades artísticas y el valor estético del cine a partir del reconocimiento de su finalidad profunda: revelar la verdad y obtener conocimiento. Argumento que Die Marquise von O nos presenta, en negativo, una reflexión metacinemática, al establecer un contraste entre los medios propios del cine y los de otras artes, como la literatura, la pintura o el teatro. La trasposición desde la historia de la marquesa hasta la reflexión sobre el cine no es anecdótica: la verdad se desvelará a través del sometimiento a la indiferente objetividad de la cámara. Die Marquise von O trata de la propia condición del cine como revelación de la verdad.This paper provides some thoughts about the nature of the cinematic image taking as a starting point a film by Éric Rohmer, Die Marquise von O, and the critical and theoretical writings of the French director. I read the film as exemplifying what for Rohmer are the artistic potentialities and the aesthetic values of cinema; they are viewed as contributing to a deep aesthetic finality: to reveal the truth and obtain knowledge. I argue that Die Marquise von O offers a metacinematic reflection by drawing a contrast between the medium of cinema and other arts, such as literature, painting and theater. The transposition I propose from the story of the marquise to a reflection on the nature of cinema is not merely incidental, because in both cases truth will be revealed through the indifferent and objective registering of reality by the camera. Die Marquise von O talks about the condition of cinema as revelation of truth
Deleuze and world cinemas. David Martin-Jones. Londres: Continuum International Publishing Group, 2011, 288 páginas
Ferrajoli’s Equity and Aristotle’s Equity: A Critical Comparison
En este trabajo se hace un análisis crítico de la idea de equidad de Ferrajoli. Para discutir la concepción cognoscitivista de la jurisdicción defendida por el teórico italiano y el lugar que la equidad ocupa en ella (como «poder de connotación», junto a los poderes de «denotación», «comprobación fáctica» y «disposición») se propone una comparación crítica con la teoría clásica de la equidad de Aristóteles. Esta comparación contrasta ese modelo positivista con el modelo pragmático de las reglas y de la deliberación judicial como razonamiento práctico que se deriva de la idea aristotélica de «prudencia» y se encuentra en el trasfondo de la tesis de la epieikeia como «corrección de la ley». A partir de aquí se muestran, por un lado, las insuficiencias del planteamiento ferrajoliano de la jurisdicción basado en una idea de «verdad» deudora de la dicotomía positivista hecho-valor, argumentando que su tesis de la equidad como «connotación de lo que la ley denota» y «comprensión de las circunstancias de hecho del caso» mantiene en el fondo la misma posición del formalismo clásico ilustrado. Por otro lado, se destacan las inconsistencias que tal comprensión supone para el proyecto de constitucionalismo positivista de Ferrajoli, subrayando que la función judicial, y particularmente en el Estado constitucional, es indisociable de la idea de verdad como corrección práctica y de la coherencia como ideal metódico.The purpose of this paper is to elaborate a critical approach to Ferrajoli’s conception of equity. Its author undertakes a critical analysis on the cognitivist conception of jurisdiction to be found in the Italian author, particularly on the role played by equity thereof (as «power of connotation» coming along with the «denotation power», «fact finding power» and «ethical-political disposition power» of the judge) using for this purposes Aristotle’s classical theory on equity. In this comparison, Ferrajoli’s positivist model is confronted with Aristotle’s pragmatic model of rules and with judicial deliberation as practical reasoning, this latter derived from his notion of «prudence» underlying the concept of epieikeia as «correction of the law». It is then that the deficiencies of Ferrajoli’s approach to jurisdiction, based on a conception of the notion of truth following the positivist fact-value dichotomy, are observed. The author argues that Ferrajoli’s thesis on equity as «connotation of what is denoted by the law» and «understanding of the factual circumstances of the case» really tantamount to the classical formalist conception on jurisdiction. Moreover it is argued that holding this understanding of jurisdiction turns Ferrajoli’s positivist constitutionalism inconsistent. For the judicial function, especially in the constitutional rule-of-law state, needs to be considered as inseparable from the notion of truth as practical correction and from the methodical ideal of coherence.Este trabajo ha sido realizado en el marco del proyecto de investigación Constitucionalismo y argumentación (DER2010-21032) financiado por el Ministerio de Ciencia e Innovación
Understanding and the value of intellectual autonomy
This research has been funded by the Spanish Ministry of Science and Innovation through a research grant (FFI2017-87395-P
Encoding of arbitrary micrometric complex illumination patterns with reduced speckle
In nonlinear microscopy, phase-only spatial light modulators (SLMs) allow
achieving simultaneous two-photon excitation and fluorescence emission from specific regionof-interests (ROIs). However, as iterative Fourier transform algorithms (IFTAs) can only
approximate the illumination of selected ROIs, both image formation and/or signal acquisition
can be largely affected by the spatial irregularities of the illumination patterns and the speckle
noise. To overcome these limitations, we propose an alternative complex illumination method
(CIM) able to generate simultaneous excitation of large-area ROIs with full control over the
amplitude and phase of light and reduced speckle. As a proof-of-concept we experimentally
demonstrate single-photon and second harmonic generation (SHG) with structured
illumination over large-area ROIs
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