Search results for "Rationality"
showing 10 items of 144 documents
Specialization and herding behavior of trading firms in a financial market
2008
Agent-based models of financial markets usually make assumptions about agent’s preferred stylized strategies. Empirical validations of these assumptions have not been performed so far on a full-market scale. Here we present a comprehensive study of the resulting strategies followed by the firms which are members of the Spanish Stock Exchange. We are able to show that they can be characterized by a resulting strategy and classified in three well- defined groups of firms. Firms of the first group have a change of inventory of the traded stock which is positively correlated with the synchronous stock return whereas firms of the second group show a negative correlation. Firms of the third group…
Teologia w poszukiwaniu kryteriów prawdziwości religii
2020
The aim of the article is to develop criteriology that would enable to evaluate authenticity of particular religions and to distinguish authentic religions from pseudoreligious phenomena. Given the complexity of the problematics, first the historical background of the issue was presented and the attention was paid to its contemporary context. The next step was the analysis of notions crucial for criteriology of religion including “the truth”, “authenticity”, “religion”, and “authenticity of religion”. A major challenge for theology of today is the phenomenon of relativism questioning the existence of universal standards of rationality and consequently contradicting the possibility to develo…
What is new in new materialism for a newcomer?
2018
AbstractHaving recently emerged as an intellectual project, new materialism (NM) is extending to different fields, including sport, exercise and health studies. However, it is still unclear why and how NM is new, which can jeopardise its potential impact in academia and society. The aim of this paper is to discuss the newness of NM and to explore how it plays out in relation to different issues, such as knowledge translation and partisan positions. At the same time, NM is used as a way of understanding my own positionality as a newcomer who is becoming an academic within a field having manifold intellectual debates while being shaped by a neoliberal rationality. Reasons as to why NM has to …
Understanding how the strategy formation process interacts with the management of complex work
2011
PurposeThe purpose of this paper is to analyse how the strategy formation process takes place studying the relevance of the integrative perspective and the use of the variables rationality, implication and vision, and verifying the relationship between an integrative strategy formation process and the management of work and the consequences of this relationship in terms of performance.Design/methodology/approachThe paper adopted a qualitative methodology, specifically a simple case analysis, following a six‐stage process: establishing the research objectives, the theoretical research framework, unit and the level of analysis, selecting the study cases and a pilot case, and ellaborating the …
Unirationality of Hurwitz spaces of coverings of degree <= 5
2011
Let $Y$ be a smooth, projective curve of genus $g\geq 1$ over the complex numbers. Let $H^0_{d,A}(Y)$ be the Hurwitz space which parametrizes coverings $p:X \to Y$ of degree $d$, simply branched in $n=2e$ points, with monodromy group equal to $S_d$, and $det(p_{*}O_X/O_Y)$ isomorphic to a fixed line bundle $A^{-1}$ of degree $-e$. We prove that, when $d=3, 4$ or $5$ and $n$ is sufficiently large (precise bounds are given), these Hurwitz spaces are unirational. If in addition $(e,2)=1$ (when $d=3$), $(e,6)=1$ (when $d=4$) and $(e,10)=1$ (when $d=5$), then these Hurwitz spaces are rational.
Corrigendum: Unirationality of Hurwitz Spaces of Coverings of Degree ≤5
2017
We correct Proposition 3.12 and Lemma 3.13 of the paper published in Vol. 2013, No.13, pp.3006-3052. The corrections do not affect the other statements of the paper. In this note, we correct a flow in the statement of Proposition 3.12 of [1] which also leads to a modification in the statement of Lemma 3.13 of [1]. We recall that in this proposition one considers morphisms of schemes X ?→π Y ?→q S, where q is proper, flat, with equidimensional fibers of dimension n and π is finite, flat and surjective. Imposing certain conditions on the fibers it is claimed that the loci of s € S fulfilling these conditions are open subsets of S. A missing condition should be added and the correct version of…
Rationality and Sylow 2-subgroups
2010
AbstractLet G be a finite group. If G has a cyclic Sylow 2-subgroup, then G has the same number of irreducible rational-valued characters as of rational conjugacy classes. These numbers need not be the same even if G has Klein Sylow 2-subgroups and a normal 2-complement.
Homological Projective Duality for Determinantal Varieties
2016
In this paper we prove Homological Projective Duality for crepant categorical resolutions of several classes of linear determinantal varieties. By this we mean varieties that are cut out by the minors of a given rank of a n x m matrix of linear forms on a given projective space. As applications, we obtain pairs of derived-equivalent Calabi-Yau manifolds, and address a question by A. Bondal asking whether the derived category of any smooth projective variety can be fully faithfully embedded in the derived category of a smooth Fano variety. Moreover we discuss the relation between rationality and categorical representability in codimension two for determinantal varieties.
The Rationality Criterion
2014
In this chapter we explain a remarkable theorem of Miyaoka [32] which asserts that a foliation whose cotangent bundle is not pseudoeffective is a foliation by rational curves. The original Miyaoka’s proof can be thought as a foliated version of Mori’s technique of construction of rational curves by deformations of morphisms in positive characteristic [33].
Hurwitz spaces of quadruple coverings of elliptic curves and the moduli space of abelian threefolds A_3(1,1,4)
2005
We prove that the moduli space A_3(1,1,4) of polarized abelian threefolds with polarization of type (1,1,4) is unirational. By a result of Birkenhake and Lange this implies the unirationality of the isomorphic moduli space A_3(1,4,4). The result is based on the study the Hurwitz space H_{4,n}(Y) of quadruple coverings of an elliptic curve Y simply branched in n points. We prove the unirationality of its codimension one subvariety H^{0}_{4,A}(Y) which parametrizes quadruple coverings ��:X --> Y with Tschirnhausen modules isomorphic to A^{-1}, where A\in Pic^{n/2}Y, and for which ��^*:J(Y)--> J(X) is injective. This is an analog of the result of Arbarello and Cornalba that the Hurwitz s…