Browsing by Author "Gheondea, Aurelian"
Now showing items 1-12 of 12
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Bifurcation in the evolution of certainty in a small decision-making group by consensus
(2021-07-06)In a previous paper, the evolution of certainty measured during a consensus-based small-group decision process was shown to oscillate to an equilibrium value for about two-thirds of the participants in the experiment. ... -
The classical SIR model in epidemiology
(Romanian Mathematical Society, 2020)This is a survey note in which we describe the classical SIR model in mathematical epidemiology, a bit of qualitative analysis, its Euler discretisation, and some simulations. -
Corrigendum to “representations of ⁎-semigroups associated to invariant kernels with values adjointable operators” [Linear Algebra Appl. 486 (2015) 361–388]
(2020)We correct a lemma by adding the assumption that the ordered ⁎-space is Archimedean and show by counter-examples and examples that this is needed. -
Editorial Preface
(The Theta Foundation, 2003) -
Interpolation for completely positive maps: Numerical solutions
(Societatea de Stiinte Matematice din Romania, 2018)We present a few techniques to find completely positive maps between full matrix algebras taking prescribed values on given data, based on semidefinite programming, convex minimization supported by a numerical example, as ... -
Invariant weakly positive semidefinite kernels with values in topologically ordered ∗-spaces
(Instytut Matematyczny PAN, 2019)We consider weakly positive semidefinite kernels valued in ordered ∗-spaces with or without certain topological properties, and investigate their linearisations (Kolmogorov decompositions) as well as their reproducing ... -
Kreǐn spaces induced by symmetric operators
(Academia Romana * Institutul de Matematica, 2009)We introduce the notion of Kreǐn space induced by a densely defined symmetric operator in a Hilbert space, as an abstract notion of indefinite energy spaces. Characterizations of existence and uniqueness, as well as certain ... -
On generalised triplets of Hilbert spaces
(Editura Academiei Romane, 2020)We compare the concept of triplet of closely embedded Hilbert spaces with that of generalised triplet of Hilbert spaces in the sense of Berezanskii by showing when they coincide, when they are different, and when starting ... -
Probability error bounds for approximation of functions in reproducing kernel Hilbert spaces
(Hindawi Limited, 2021-05-03)We find probability error bounds for approximations of functions f in a separable reproducing kernel Hilbert space H with reproducing kernel K on a base space X, firstly in terms of finite linear combinations of functions ... -
Reproducing kernel kreĭn spaces
(Springer Basel, 2015)This chapter is an introduction to reproducing kernel Kre?in spaces and their interplay with operator valued Hermitian kernels. Existence and uniqueness properties are carefully reviewed. The approach used in this survey ... -
The spectral theorem for locally normal operators
(AGH University of Science and Technology, 2018)We prove the spectral theorem for locally normal operators in terms of a locally spectral measure. In order to do this, we first obtain some characterisations of local projections and we single out and investigate the ... -
Symmetries versus conservation laws in dynamical quantum systems: a unifying approach through propagation of fixed points
(Birkhauser Verlag AG, 2018)We unify recent Noether-type theorems on the equivalence of symmetries with conservation laws for dynamical systems of Markov processes, of quantum operations, and of quantum stochastic maps, by means of some abstract ...
