Results 81 to 90 of about 690 (191)

Finite‐Block Polynomial and Volterra Structure in Reservoir Computing

Numerical Linear Algebra with Applications, Volume 33, Issue 4, August 2026.
ABSTRACT Reservoir computing is analyzed through the algebraic structure generated by finite‐width reservoirs on fixed input blocks. For linear and quadratic logistic activations, the induced input‐to‐state map admits an exact finite Volterra representation, yielding an explicit characterization of the associated hypothesis class.
Alfio Borzì
wiley   +1 more source

On new approach to semi-Fredholm theory in unital C^*-algebras

Pracì Mìžnarodnogo Geometričnogo Centru
Axiomatic Fredholm theory in unital C*-algebras was established in [D. Kečkić, Z. Lazović, Acta Sci. Math., 83(3-4):629--655, 2017]. Following the pure algebraic approach by Kečkić and Lazović, in the author's paper [S. Ivković, Banach J. Math. Anal., 17:
Stefan Ivkovic
doaj   +1 more source

Randomized Algorithms for Streaming Low‐Rank Approximation in Tree Tensor Network Format

Numerical Linear Algebra with Applications, Volume 33, Issue 4, August 2026.
ABSTRACT In this work, we present the tree tensor network Nyström (TTNN), an algorithm that extends recent research on streamable tensor approximation, such as for Tucker and tensor‐train formats, to the more general tree tensor network format, enabling a unified treatment of various existing methods.
Alberto Bucci, Gianfranco Verzella
wiley   +1 more source

Hilbert polynomials of the algebras of $SL_ 2$-invariants

Karpatsʹkì Matematičnì Publìkacìï, 2018
We consider one of the fundamental problems of classical invariant theory, the research of Hilbert polynomials for an algebra of invariants of Lie group $SL_2$.
N.B. Ilash
doaj   +1 more source

The Mathematical History Behind the Granger–Johansen Representation Theorem

Oxford Bulletin of Economics and Statistics, Volume 88, Issue 4, Page 587-602, August 2026.
ABSTRACT When can a vector time series that is integrated once (i.e., becomes stationary after taking first differences) be described in error correction form? The answer to this is provided by the Granger–Johansen representation theorem. From a mathematical point of view, the theorem can be viewed as essentially a statement concerning the geometry of ...
Johannes M. Schumacher
wiley   +1 more source

Finiteness of the Hölder–Brascamp–Lieb constant revisited

Bulletin of the London Mathematical Society, Volume 58, Issue 8, August 2026.
Abstract Abstract Hölder–Brascamp–Lieb inequalities have become a ubiquitous tool in Fourier analysis in recent years, due in large part to a theorem of Bennett et al. characterizing finiteness of the Hölder–Brascamp–Lieb constant. Here we provide a new characterization of a substantially different nature involving directed graphs of subspaces.
Philip T. Gressman
wiley   +1 more source

NORMED HILBERT ALGEBRAS

Honam Mathematical Journal, 2007
In this paper, we introduce the notion of a norm in Hilbert algebras, and discuss some properties of Cauchy sequences.
Sun-Shin Ahn, Kyoung-Ja Lee, Keum-Sook So   +2 more
openaire   +1 more source

Fine multidegrees, universal Gröbner bases, and matrix Schubert varieties

Journal of the London Mathematical Society, Volume 114, Issue 2, August 2026.
Abstract We give a criterion for a collection of polynomials to be a universal Gröbner basis for an ideal in terms of the multidegree of the closure of the corresponding affine variety in (P1)N$(\mathbb {P}^1)^N$. This criterion can be used to give simple proofs of several existing results on universal Gröbner bases.
Daoji Huang, Matt Larson
wiley   +1 more source

New elements in Hilbert algebras.

TFSS
In this paper‎, ‎the notion of commutator of elements of a Hilbert algebra are introduced and some properties are given‎. ‎The notions of involution element and Engel element in Hilbert algebras are introduced‎. ‎Many different characterizations of them are given‎.
openaire   +2 more sources

On Birkhoff – James and Roberts orthogonality

Special Matrices, 2018
In this paper we present some recent results on characterizations of the Birkhoff-James and the Roberts orthogonality in C*-algebras and Hilbert C*-modules.
Arambašic Ljiljana, Rajic Rajna
doaj   +1 more source