229 research outputs found
Peirce y el lugar de la semiótica
Según Max H. Fisch, mientras el joven Peirce considera la lógica como una parte de la semiótica, en la obra de madurez, la lógica es identificada con la semiótica. En este artículo se ofrece una reconstrucción alternativa de las relaciones entre lógica y semiótica en el pensamiento de Peirce. la primera parte de la tesis de Fisch es sustancialmente correcta: en sus primeros escritos (1865-1866) la lógica es una simbolística objetiva, es decir, una parte de una parte de la ciencia general de todas las representaciones (la semiótica). Parte de la tesis de Fisch debe, en cambio, ser reconsiderada. Para el Peirce maduro (1902-1913), la lógica debe incluir una rama que se ocupe de la clasificación de los signos, es decir, una gramática especulativa.According to Max H. Fisch, while the young Peirce considers logic as a part of semiotics, in his mature writings logic is identified with semiotics. This paper offers an alternative reconstruction of the relations between logic and semiotics in Peirce's thought. The first part of Fisch's thesis is substantially correct: in his earliest writings (1865-1866) logic is objective symbolistic, that is a part of a part of the general science of all representations (semiotics). The second part of Fisch's thesis requires emendation. For the mature Peirce (1902-1913), logic has to include as a proper part a preliminary study of its own boundaries. In other words, logic has to comprise a branch devoted to the classifcation of signs, namely a speculative grammar
Critical Behavior of the Marinari-Parisi Model
We consider the continuum string theory corresponding to the Marinari-Parisi
supersymmetric matrix model. We argue that the world-sheet physics is exotic,
and different from any known supersymmetric string theory. The embedding
superspace coordinates become disordered on the world-sheet, but because of the
noncompactness of the embedding time the disorder becomes complete only at
asymptotic world-sheet scales.Comment: 7 pages, LaTe
Extensions of the N=2 Supersymmetric a=-2 Boussinesq Hierarchy
We present two different Lax operators for a manifestly N=2 supersymmetric
extension of "a=-2" Boussinesq hierarchy . The first is the supersymmetric
generalization of the Lax operator of the Modified KdV equation. The second is
the generalization of the supersymmetric Lax operator of the N=2 supersymmetric
a=-2 KdV system. The gauge transformation of the first Lax operator provide the
Miura link between the "small" N=4 supersymmetric conformal algebra and the
supersymmetric algebra .Comment: LaTex, new references added, minor typos corrected, e-mail:
[email protected]
Integrable Extensions of N=2 Supersymmetric KdV Hierarchy Associated with the Nonuniqueness of the Roots of the Lax operator
We preesent a new supersymmetric integrable extensions of the a=4,N=2 KdV
hierarchy. The root of the supersymmetric Lax operator of the KdV equation is
generalized, by including additional fields. This generalized root generate new
hierarchy of integrable equations, for which we investigate the hamiltonian
structure. In special case our system describes the interaction of the KdV
equation with the two MKdV equations.Comment: 9 pages Latex,e-mail [email protected]
The Supersymmetric Effective Action of the Heterotic String in Ten Dimensions
We construct the supersymmetric completion of quartic -actions in the
ten-dimensional effective action of the heterotic string. Two invariants, of
which the bosonic parts are known from one-loop string amplitude calculations,
are obtained. One of these invariants can be generalized to an
-invariant for supersymmetric Yang-Mills theory coupled to
supergravity.
Supersymmetry requires the presence of -terms, ( for
Yang-Mills) which correspond to counterterms in the Green-Schwarz anomaly
cancellation. Within the context of our calculation the -term from
the tree-level string effective action does not allow supersymmetrization.Comment: 42 pages, UG-9/9
Duality of Type II 7-branes and 8-branes
We present a version of ten-dimensional IIA supergravity containing a 9-form
potential for which the field equations are equivalent to those of the
standard, massless, IIA theory for vanishing 10-form field strength, ,
and to those of the `massive' IIA theory for non-vanishing . We present
a multi 8-brane solution of these equations that generalizes the 8-brane of
Polchinski and Witten. We show that this solution is T-dual to a new multi
7-brane solution of compactified IIB supergravity, and that the latter is
T-dual to the IIA 6-brane. When combined with the U-duality of the
type IIB superstring, the T-duality between type II 7-branes and 8-branes
implies a quantization of the cosmological constant of type IIA superstring
theory. These results are made possible by the construction of a new {\it
massive} N=2 D=9 supergravity theory. We also discuss the 11-dimensional
interpretation of these type II p-branes.Comment: Includes corrections to last section that will appear in the version
to be published in Nuclear Physics B. 36 pp. Phyzz
Some Aspects of Spherical Symmetric Extremal Dyonic Black Holes in 4d N=1 Supergravity
In this paper we study several aspects of extremal spherical symmetric black
hole solutions of four dimensional N=1 supergravity coupled to vector and
chiral multiplets with the scalar potential turned on. In the asymptotic region
the complex scalars are fixed and regular which can be viewed as the critical
points of the black hole and the scalar potentials with vanishing scalar
charges. It follows that the asymptotic geometries are of a constant and
non-zero scalar curvature which are generally not Einstein. These spaces could
also correspond to the near horizon geometries which are the product spaces of
a two anti-de Sitter surface and the two sphere if the value of the scalars in
both regions coincides. In addition, we prove the local existence of
non-trivial radius dependent complex scalar fields which interpolate between
the horizon and the asymptotic region. We finally give some simple
{\lC}^{n}-models with both linear superpotential and gauge couplings.Comment: 17 pages, no figure. Added an author. Major revision: typos and
grammar corrected, some statements modified, added a section about local
existence of scalar fields. Accepted for publication in Int J Mod Phys
Electron states in the quantum wire with periodic serial structure
A model quantum wire embedded in a matrix permeable to electron waves is
investigated in terms of electronic states. The wire is assumed to have a 1D
crystal structure. Through electron waves propagating in its surroundings,
lateral modes are coupled with Bloch waves propagating along the wire axis,
which results in modes splitting into multiplets. The results presented in this
study have been obtained by direct solution of the Schrodinger equation in the
effective mass approximation.Comment: submitted to Physical Review B, (5 pages, 4 figures
Un esbozo de diccionario de verbos en español desde la perspectiva de la estructura argumental. Una reflexión general sobre la naturaleza sintáctica, léxica y semántica de los verbos
Sobre la base de un aprendizaje significativo de la lengua, el objetivo de la investigación, cuyos destinatarios son, fundamentalmente, traductores, correctores, profesores de lengua española y personas interesadas en la problemática de la lengua, fue evaluar la relevancia semántica de los verbos a partir de un cuerpo de datos constituido por 150 verbos extraídos del Diccionario de la RAE (2014). El estudio se realizó desde la perspectiva sintáctico-léxico-semántica, puesto que esta determina las funciones sintácticas necesarias para formar una oración correcta. De cada verbo se consideraron las seis primeras entradas y se excluyeron las locuciones verbales y metafóricas, y se incluyeron únicamente verbos transitivos, intransitivos y pronominales.Se partió de la clasificación de papeles temáticos de V. Demonte (1990:125), quien —sobre la base de la terminología de Vendler-Dowty (1967) — plantea cuatro características inherentes del verbo y añade una taxonomía de rasgos combinatorios mínimos de [actividad / resultado] para cada clase, a saber: REALIZACIONES [+ actividad, + resultado]; ACTIVIDAD [+ actividad, -resultado]; LOGRO [- actividad + resultado] y ESTADOS [-actividad, -resultado].Del análisis surgieron inevitables dudas en cuanto a la determinación de ciertos rasgos, entre ellos el rasgo mínimo que distinguiría la realización del logro. Cotejados varios casos, se decidió desdoblar la estructura eventiva de logro en: logro absoluto y logro relativo. Por ejemplo, en Explotó una bomba, el logro es absoluto, pero en Descubrió una cueva, el logro se obtiene a partir de un proceso, es decir, de una realización. El texto refiere un descubrimiento no esperado. Sin embargo, en Descubrió la/esa cueva, con la presencia de un determinante, se infiere la existencia previa de la cueva y su hallazgo.Por otra parte, se han sumado al análisis los rasgos morfológicos y aspectuales del verbo además de determinantes (artículos y cuantificadores). Por ejemplo, “bailar” es un verbo de actividad que requiere Agente y Tema: Clara baila; Clara baila zambas. En Clara bailó una zamba con verbo en pasado simple o compuesto es verbo de realización, pero en Clara bailó la/esa zamba la presencia de un determinante orienta el rasgo de logro
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