Browsing Institutt for matematiske fag by Author "Tapia, Nikolas"
Now showing items 1-5 of 5
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Hopf-algebraic Deformations of Products and Wick Polynomials
Ebrahimi-Fard, Kurusch; Patras, Frederic; Tapia, Nikolas; Zambotti, Lorenzo (Journal article; Peer reviewed, 2018)We present an approach to cumulant–moment relations and Wick polynomials based on extensive use of convolution products of linear functionals on a coalgebra. This allows, in particular, to understand the construction of ... -
Shifted Substitution in Non-Commutative Multivariate Power Series with a View Toward Free Probability
Ebrahimi-Fard, Kurusch; Patra, Frédéric; Zambotti, Lorenzo; Tapia, Nikolas (Peer reviewed; Journal article, 2023)We study a particular group law on formal power series in non-commuting variables induced by their interpretation as linear forms on a suitable graded connected word Hopf algebra. This group law is left-linear and is ... -
Signatures in Shape analysis: An efficient approach to motion identification
Celledoni, Elena; Lystad, Pål Erik; Tapia, Nikolas (Peer reviewed; Journal article, 2019)Signatures provide a succinct description of certain features of paths in a reparametrization invariant way. We propose a method for classifying shapes based on signatures, and compare it to current approaches based on the ... -
Tropical time series, iterated-sums signatures and quasisymmetric functions
Ebrahimi-Fard, Kurusch; Tapia, Nikolas; Diehl, Joscha (Journal article; Peer reviewed, 2022) -
Wick polynomials in non-commutative probability: A group-theoretical approach
Ebrahimi-Fard, Kurusch; Patras, Frédéric; Tapia, Nikolas; Zambotti, Lorenzo (Journal article; Peer reviewed, 2021)