Search results for "DIMENSION"

Actions of complex Lie groups on analytic ?-algebras

1987

On a reduced analytic .ℂ-algebraR there are faithful analytic actions of complex Lie groups of arbitrarily high dimension if and only ifR has Krull dimension ≥2.

On some Translation Planes Admitting a Frobenius Group of Collineations

1983

Publisher Summary This chapter presents some results concerning translation planes of dimension 2 over GF(q), where q = p r . π denotes such a plane. It is assumed that π has a collineation group F of order q 2 (q-1) satisfying the condition: there exists a point V e l ∞ such that F fixes V and acts (faithfully) as a Frobenius group on l ∞ – {V}.

Topology, Matter, and Space, I: Topological Notions in 19th-Century Natural Philosophy

1998

L'A. montre l'impact de la topologie dans le developpement de la theorie dynamique des phenomenes physiques ainsi que les speculations de la structure topologique de l'espace

Symmetric Surfaces with Many Singularities

2004

Abstract Let G ⊂ SO(4) denote a finite subgroup containing the Heisenberg group. In this paper we classify all such groups, we find the dimension of the spaces of G-invariant polynomials and we give equations for the generators whenever the space has dimension two. Then we complete the study of the corresponding G-invariant pencils of surfaces in ℙ3 which we started in Sarti [Sarti, A. (2000). Pencils of symmetric surfaces in ℙ3(C). J. Algebra 246:429–452]. It turns out that we have five more pencils, two of them containing surfaces with nodes.

Codimension growth of special simple Jordan algebras

2009

Let $R$ be a special simple Jordan algebra over a field of characteristic zero. We exhibit a noncommutative Jordan polynomial $f$ multialternating on disjoint sets of variables which is not a polynomial identity of $R$. We then study the growth of the polynomial identities of the Jordan algebra $R$ through an analysis of its sequence of Jordan codimensions. By exploiting the basic properties of the polynomials $f$, we are able to compute the exponential rate of growth of the sequence of Jordan codimensions of $R$ and prove that it equals the dimension of the Jordan algebra over its center. We also show that for any finite dimensional special Jordan algebra, such exponential rate of growth c…

Perron type integral on compact zero-dimensional Abelian groups

2008

Perron and Henstock type integrals defined directly on a compact zero-dimensional Abelian group are studied. It is proved that the considered Perron type integral defined by continuous majorants and minorants is equivalent to the integral defined in the same way, but without assumption on continuity of majorants and minorants.

Gibbs measures in a markovian context and dimension

2001

On many-sorted algebraic closure operators

2004

A theorem of Birkhoff-Frink asserts that every algebraic closure operator on an ordinary set arises, from some algebraic structure on the set, as the corresponding generated subalgebra operator. However, for many-sorted sets, i.e., indexed families of sets, such a theorem is not longer true without qualification. We characterize the corresponding many-sorted closure operators as precisely the uniform algebraic operators. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Mixed Valence Materials: Prussian Blue Analogues of Reduced Dimensionality (Small 16/2012)

2012

Gradient-echo and CRAZED imaging for minute detection of Alzheimer plaques in an APPV717I x ADAM10-dn mouse model.

2007

Different strategies to visualize amyloid plaques with MRI at 17.6 Tesla were investigated in a novel mouse model of Alzheimer's disease (AD). Large iron-containing plaques were observed in the thalamus, but cortical plaques did not show iron deposits. Plaques in the thalamus were visualized in vivo with the use of low-resolution, 3D gradient-echo (GRE) imaging in 82 s, and with 94-microm resolution in 34 min. The feasibility of obtaining bright contrast from plaques using the COSY revamped with asymmetric z-GRE detection (CRAZED) technique was investigated in experiments on fixed brains. The original CRAZED approach provided reduced signal near the plaques (similarly to GRE imaging) and ad…