Displaying 701 – 720 of 1070

Showing per page

On the suspension homomorphism

S. Dragotti, G. Magro, L. Parlato (2002)

Bollettino dell'Unione Matematica Italiana

In this paper we investigate the conditions for the suspension homomorphism s : Θ r - 1 F S n - 1 , x 0 Θ r F S n , x 0 is onto or an isomorphism.

On weak i -homotopy equivalences of modules

Zheng-Xu He (1984)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

Si definisce il gruppo di i —omotopia di un singolo modulo e si introduce la nozione di equivalenza i -omotopica debole. Sotto determinate condizioni per l'anello di base Λ oppure per i moduli considerati, le equivalenze i -omotopiche deboli coincidono con le equivalenze i -omotopiche (forti).

Opérades cellulaires et espaces de lacets itérés

Clemens Berger (1996)

Annales de l'institut Fourier

L’espace des configurations de p points distincts de R admet une filtration naturelle qui est induite par les inclusions des R n dans R . Nous caractérisons le type d’homotopie de cette filtration par les propriétés combinatoires d’une structure cellulaire sous-jacente, étroitement liée à la théorie des E n -opérades de May. Cela donne une approche unifiée des différents modèles combinatoires d’espaces de lacets itérés et redémontre les théorèmes d’approximation de Milgram, Smith et Kashiwabara.

Operads for n -ary algebras – calculations and conjectures

Martin Markl, Elisabeth Remm (2011)

Archivum Mathematicum

In [8] we studied Koszulity of a family t 𝒜 𝑠𝑠 d n of operads depending on a natural number n and on the degree d of the generating operation. While we proved that, for n 7 , the operad t 𝒜 𝑠𝑠 d n is Koszul if and only if d is even, and while it follows from [4] that t 𝒜 𝑠𝑠 d n is Koszul for d even and arbitrary n , the (non)Koszulity of t 𝒜 𝑠𝑠 d n for d odd and n 8 remains an open problem. In this note we describe some related numerical experiments, and formulate a conjecture suggested by the results of these computations.

Order complex of ideals in a commutative ring with identity

Nela Milošević, Zoran Z. Petrović (2015)

Czechoslovak Mathematical Journal

Order complex is an important object associated to a partially ordered set. Following a suggestion from V. A. Vassiliev (1994), we investigate an order complex associated to the partially ordered set of nontrivial ideals in a commutative ring with identity. We determine the homotopy type of the geometric realization for the order complex associated to a general commutative ring with identity. We show that this complex is contractible except for semilocal rings with trivial Jacobson radical when...

Currently displaying 701 – 720 of 1070