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Mostrando ítems 11-19 de 19
Artículo
On the singular braid monoid of an orientable surface
(American Mathematical Society, 2004)
In this paper we show that the singular braid monoid of an orientable surface can be embedded in a group. The proof is purely topological, making no use of the monoid presentation.
Artículo
A class of nilpotent lie algebras
(Taylor and Francis, 2000)
A p-filiform Lie algebra g is a nilpotent Lie algebra for which Goze’s invariant is (n–p,1,…,1). These Lie algebras are well known for P ≥ n-4n = dim(g). In this paper we describe the p-filiform Lie algebras, for p = n-5 ...
Artículo
Naturally graded quasi-filiform Leibniz algebras
(Elsevier, 2009)
The classification of naturally graded quasi-filiform Lie algebras is known; they have the characteristic sequence .n - 2; 1; 1/ where n is the dimension of the algebra. In the present paper we deal with naturally graded ...
Artículo
Heisenberg superalgebras
(Taylor and Francis, 2009)
Heisenberg algebras are the only Lie algebras (g, [, ]) which verify [g, g] = Z(g) and dim(Z(g)) = 1, where Z denotes the center of the algebra. We classify nilpotent Lie superalgebras that verify the same algebraic ...
Artículo
Quasi-free divisors and duality
(Elsevier, 2004)
We prove a duality theorem for some logarithmic D-modules associated with a class of divisors. We also give some results for the locally quasi-homogeneous case.
Artículo
Homomorphisms and polynomial invariants of graphs
(Elsevier, 2009)
This paper initiates a general study of the connection between graph homomorphisms and the Tutte polynomial. This connection can be extended to other polynomial invariants of graphs related to the Tutte polynomial such ...
Artículo
Zero-sum balanced binary sequences
(University of West Georgia, 2007)
F whic or h ev is ery p balanced, ositive in i.e., teger whose n ≡ 0 asso mod ciated 4, we Steinhaus construct a triangle zero-sum contains {±1} as man -sequence y +1’s of as length 1’s. n This ...
Artículo
Algebra Structures on the Twisted Eilenberg–Zilber Theorem
(Taylor and Francis, 2007)
Let G, G′, and G ×τ G′ be three simplicial groups (not necessarily abelian) and C N (G) ⊗ t C N (G′) be the “twisted” tensor product associated to C N (G ×τ G′) by the twisted Eilenberg–Zilber theorem. Here we prove that ...
Artículo
HPT and cocyclic operations
(International Press, 2005)
We reinterpret the classical theory of cocyclic operations in terms of permutations and homotopy equivalences of explicit chains. The essential tools we use are Homological Perturbation Theory and Eilenberg–Zilber ...