1,720,994 research outputs found
Classifying Algebras with Graded Involutions or Superinvolutions with Multiplicities of their Cocharacter Bounded by One
Get PDFLet A be superalgebra over a field of characteristic zero and let ∗ be either a graded involution or a superinvolution defined on A. In this paper we characterize the ∗-algebras whose ∗-cocharacter has multiplicities bounded by one, showing a set of ∗-polynomial identities satisfied by such algebras
Varieties of special Jordan algebras of almost polynomial growth
Get PDFLet J be a special Jordan algebra and let cn(J) be its corresponding codimension sequence. The aim of this paper is to prove that in case J is finite dimensional, such a sequence is polynomially bounded if and only if the variety generated by J does not contain UJ2, the special Jordan algebra of 2×2 upper triangular matrices. As an immediate consequence, we prove that UJ2 is the only finite dimensional special Jordan algebra that generates a variety of almost polynomial growth
Central polynomials of graded algebras: Capturing their exponential growth
Get PDFLet G be a finite abelian group and let A be an associative G-graded algebra over a field of characteristic zero. A central G-polynomial is a polynomial of the free associative G-graded algebra that takes central values for all graded substitutions of homogeneous elements of A. We prove the existence and the integrability of two limits called the central G-exponent and the proper central G-exponent that give a quantitative measure of the growth of the central G-polynomials and the proper central G-polynomials, respectively. Moreover, we compare them with the G-exponent of the algebra
The upper triangular matrix algebra and its generalized polynomial identities
Get PDFLet be the algebra of upper triangular matrices over a field of characteristic zero. Here we study the generalized polynomial identities of , i.e., identical relations holding for regarded as -algebra. We determine a set of two generators of the -ideal of generalized polynomial identities of and compute the exact values of the corresponding sequence of generalized codimensions. Moreover, we give a complete description of the space of multilinear generalized identities in variables in the language of Young diagrams through the representation theory of the symmetric group . Finally, we prove that, unlike in the ordinary case, the generalized variety of -algebras generated by has no almost polynomial growth; nevertheless, we exhibit two distinct generalized varieties of almost polynomial growth.12 page
On the colength sequence of G-graded algebras
No full textLet F be a field of characteristic zero and let A be an Falgebra graded by a finite group G of order k . Given a non-negative integer n and a sum n = n1 1 + + nk k of k non-negative integers, we associate a S ( n )-module to A , where S ( n ) := S n 1 x x Snk, n k , and we denote its S ( n )-character by chi ( n ) ( A ). In this paper, for all sum n = n1 1 + +nk, n k , we make explicit the decomposition of chi ( n ) ( A ) for some important G-graded algebras A and we compute the number lG n(A) G n ( A ) of irreducibles appearing in all such decompositions. Our main goal is to classify G-graded algebras A such that the sequence lGn(A) G n ( A ) is bounded by three
On multiplicities of cocharacters for algebras with superinvolution
Get PDFIn this paper we deal with finitely generated superalgebras with superinvolution, satisfying a non-trivial identity, whose multiplicities of the cocharacters are bounded by a constant. Along the way, we prove that the codimension sequence of such algebras is polynomially bounded if and only if their colength sequence is bounded by a constan
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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