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Mostrando ítems 1-10 de 18
Artículo
The symmetric action on secondary homotopy groups
(The Belgian Mathematical Society, 2008-11)
We show that the symmetric track groups Sym(n), which are extensions of the symmetric groups Sym(n) associated to the second Stiefel-Whitney class, act as crossed modules on the secondary homotopy groups of a pointed space.
Artículo
On the cycling operation in braid groups
(Elsevier, 2008-09-06)
The cycling operation is a special kind of conjugation that can be applied to elements in Artin’s braid groups, in order to reduce their length. It is a key ingredient of the usual solutions to the conjugacy problem in ...
Artículo
The 1-type of a Waldhausen K-theory spectrum
(Elsevier, 2007-12-01)
We give a small functorial algebraic model for the 2-stage Postnikov section of the K-theory spectrum of a Waldhausen category and use our presentation to describe the multiplicative structure with respect to biexact functors.
Artículo
Estimates for singular multiplicative character sums
(Duke University Press, 2005)
We give some estimates for multiplicative character sums on quasiprojective varieties over finite fields depending on the severity of the singularities of the variety at infinity. We also remove the hypothesis of ...
Artículo
Valuations in algebraic field extensions
(Elsevier, 2007-06-15)
Let K → L be an algebraic field extension and ν a valuation of K. The purpose of this paper is to describe the totality of extensions {ν′} of ν to L using a refined version of MacLane’s key polynomials. In the basic case ...
Artículo
Maltsiniotis's first conjecture for K1
(Duke University Press, 2008)
We show that K1(E) of an exact category E agrees with K1(DE) of the associated triangulated derivator DE. More generally we show that K1(W) of a Waldhausen category W with cylinders and a saturated class of weak equivalences ...
Artículo
Triangulated categories without models
(Springer, 2007-11)
We exhibit examples of triangulated categories which are neither the stable category of a Frobenius category nor a full triangulated subcategory of the homotopy category of a stable model category. Even more drastically ...
Artículo
Purity of exponential sums on An
(Kluwer, 2006-03)
We give a purity result for two kinds of exponential sums of the type ∑x∈knψ(f(x)), where k is a finite field of characteristic p and ψ:k→C⋆ is a non-trivial additive character. In the first case, f∈k[x1,…,xn] is a polynomial ...
Artículo
The cyclic sliding operation in Garside groups
(Springer, 2010-05)
We present a new operation to be performed on elements in a Garside group, called cyclic sliding, which is introduced to replace the well known cycling and decycling operations. Cyclic sliding appears to be a more natural ...
Artículo
Solving the conjugacy problem in Garside groups by cyclic sliding
(Elsevier, 2010-06)
We present a solution to the conjugacy decision problem and the conjugacy search problem in Garside groups, which is theoretically simpler than the usual one, with no loss of efficiency. This is done by replacing the well ...