Results 61 to 70 of about 43,216 (196)

The Moore–Penrose Inverse and Product Decomposition of Idempotent Operators on Hilbert C*-Modules

Axioms
We study the Moore–Penrose inverse of idempotent operators on Hilbert C*-modules. First, we extend the computation of the Moore–Penrose inverse of an idempotent operator and its difference from the range projection to this setting.
Wei Luo
doaj   +1 more source

Threads without idempotents [PDF]

Proceedings of the American Mathematical Society, 1961
If a thread S has no idempotents and if S2 = S, then S is iseomorphic with the real interval (0, 1) under ordinary multiplication [2, Corollary 5.6]. Although the result is not nearly as pleasing as the special case just quoted, we shall give here a description of any thread without idempotents.
openaire   +1 more source

On cohomology of locally profinite sets

Proceedings of the London Mathematical Society, Volume 132, Issue 5, May 2026.
Abstract We construct a locally profinite set of cardinality ℵω$\aleph _{\omega }$ with infinitely many first cohomology classes of which any distinct finite product does not vanish. Building on this, we construct the first example of a nondescendable faithfully flat map between commutative rings of cardinality ℵω$\aleph _{\omega }$ within Zermelo ...
Ko Aoki
wiley   +1 more source

Idempotent Elements of Weak Projection Generalized Hypersubstitutions

Discussiones Mathematicae - General Algebra and Applications, 2018
A generalized hypersubstitution of type τ = (ni)i∈I is a mapping σ which maps every operation symbol fi to the term σ (fi) and may not preserve arity.
Lekkoksung Nareupanat, Jampachon Prakit
doaj   +1 more source

Idempotent Noether lattices [PDF]

Proceedings of the American Mathematical Society, 1969
In his paper, Abstract commutative ideal theory [2 ], Dilworth proved that a Noether lattice on which the multiplication is the meet operation is a finite Boolean algebra. This note proves that if the multiplication in a Noether lattice is idempotent (A2= A for all A in the lattice), then the lattice is a finite Boolean algebra.
openaire   +2 more sources

Recursive and Cyclic Constructions for Double‐Change Covering Designs

Journal of Combinatorial Designs, Volume 34, Issue 4, Page 198-209, April 2026.
ABSTRACT A double‐change covering design (DCCD) is a v‐set V and an ordered list L of b blocks of size k where every pair from V must occur in at least one block and each pair of consecutive blocks differs by exactly two elements. It is minimal if it has the fewest blocks possible and circular when the first and last blocks also differ by two elements.
Amanda Lynn Chafee, Brett Stevens
wiley   +1 more source

Pentagonal quasigroups, their translatability and parastrophes

Open Mathematics, 2021
Any pentagonal quasigroup QQ is proved to have the product xy=φ(x)+y−φ(y)xy=\varphi \left(x)+y-\varphi (y), where (Q,+)\left(Q,+) is an Abelian group, φ\varphi is its regular automorphism satisfying φ4−φ3+φ2−φ+ε=0{\varphi }^{4}-{\varphi }^{3}+{\varphi }^
Dudek Wieslaw A., Monzo Robert A. R.
doaj   +1 more source

On the existence of idempotent liftings [PDF]

Proceedings of the American Mathematical Society, 1989
An existence theorem for idempotent liftings is proved. This implies that every compact measure space with full support and separable measure algebra admits an idempotent lifting.
openaire   +2 more sources

Tessellation Groups, Harmonic Analysis on Non‐Compact Symmetric Spaces and the Heat Kernel in View of Cartan Convolutional Neural networks

Fortschritte der Physik, Volume 74, Issue 4, April 2026.
ABSTRACT In this paper, we continue the development of the Cartan neural networks programme, launched with three previous publications, by focusing on some mathematical foundational aspects that we deem necessary for our next steps forward. The mathematical and conceptual results are diverse and span various mathematical fields, but the inspiring ...
Pietro Fré, Federico Milanesio, Marcelo Oyarzo, Matteo Santoro, Mario Trigiante   +4 more
wiley   +1 more source

THE TRIPLE IDEMPOTENT GRAPH OF THE RING Z_n

Barekeng
Let  be a commutative ring, and  denote the set of all idempotent elements of . The triple idempotent graph of , denoted by , is defined as an undirected simple graph whose vertex set .
Vika Yugi Kurniawan, Bayu Purboutomo, Nughthoh Arfawi Kurdhi   +2 more
doaj   +1 more source