Results 31 to 40 of about 17,323 (202)
Singular matrices that are products of two idempotents or products of two nilpotents
Special Matrices, 2021 Over commutative domains we characterize the singular 2 × 2 matrices which are products of two idempotents or products of two nilpotents. The relevant casees are the matrices with zero second row and the singular matrices with only nonzero entries.
Călugăreanu Grigore
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Algebraic Quantum Mechanics and Pregeometry [PDF]
, 2006 We discuss the relation between the q-number approach to quantum mechanics suggested by Dirac and the notion of "pregeometry" introduced by Wheeler. By associating the q-numbers with the elements of an algebra and regarding the primitive idempotents as ...
Bohm, D., Davies, Philip, Hiley, B.
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Variety of idempotents in nonassociative algebras
, 2018 In this paper, we study the variety of all nonassociative (NA) algebras from the idempotent point of view. We are interested, in particular, in the spectral properties of idempotents when algebra is generic, i.e. idempotents are in general position.
A Matsuo +14 more
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A method for constructing idempotents in a unital algebra
Учёные записки Казанского университета: Серия Физико-математические наукиA method is proposed for constructing idempotents in a unital algebra 𝒜 using n arbitrary idempotents P1,...,Pn from this algebra. The properties of the resulting idempotents P = P(P1,...,Pn) are investigated; for n = 2 and n = 3, explicit forms of the ...
M. Khadour
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Idempotent 2x2 matrices over linearly ordered abelian groups [PDF]
Categories and General Algebraic Structures with ApplicationsIn this paper we study multiplicative semigroups of $2\times 2$ matrices over a linearly ordered abelian group with an externally added bottom element. The multiplication of such a semigroup is defined by replacing addition and multiplication by join and
Valdis Laan, Marilyn Kutti
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The Relationship between E-Semigroups and R-Semigroups
Journal of Mathematics, 2023 A semigroup is called an E-semigroup (R-semigroup) if the set of all idempotents (the set of all regular elements) forms a subsemigroup. In this paper, we introduce the concept of V-semigroups and establish the relationship between the three classes of ...
Ze Gu
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An inversion formula for the primitive idempotents of the trivial source algebra
, 2018 Formulas for the primitive idempotents of the trivial source algebra, in characteristic zero, have been given by Boltje and Bouc--Th\'{e}venaz. We shall give another formula for those idempotents, expressing them as linear combinations of the elements of
Barker, Laurence
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Intraday Functional PCA Forecasting of Cryptocurrency Returns
Journal of Forecasting, EarlyView.ABSTRACT We study the functional PCA (FPCA) forecasting method in application to functions of intraday returns on Bitcoin. We show that improved interval forecasts of future return functions are obtained when the conditional heteroscedasticity of return functions is taken into account.
Joann Jasiak, Cheng Zhong
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The local geometry of idempotent Schur multipliers
Forum of Mathematics, PiA Schur multiplier is a linear map on matrices which acts on its entries by multiplication with some function, called the symbol. We consider idempotent Schur multipliers, whose symbols are indicator functions of smooth Euclidean domains.
Javier Parcet +2 more
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Journal of Time Series Analysis, EarlyView.ABSTRACT The paper deals with the construction of a synthetic indicator of economic growth, obtained by projecting a quarterly measure of aggregate economic activity, namely gross domestic product (GDP), into the space spanned by a finite number of smooth principal components, representative of the medium‐to‐long‐run component of economic growth of a ...
Alessandro Giovannelli +2 more
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