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941.
It is shown that all Banach space operators which have Fourier
type p(1 < p 2) with respect to a second countable
locally compact abelian group G also have
Fourier type p with
respect to every closed discrete subgroup H
of G. The same
statement holds for any closed subgroup H
of G when p = 2.
Also shown as a corollary is that Fourier type 2 operators have
Walsh type 2.
Received: 10 June 2002 相似文献
942.
We classify (up to Morita equivalence) all tame weakly symmetric finite
dimensional algebras over an algebraically closed field having simply connected
Galois coverings, nonsingular Cartan matrices and the stable Auslander-Reiten
quivers consisting only of tubes. In particular, we prove that these algebras
have at most four simple modules.Received: 25 February 2002 相似文献
943.
A procedure is described for constructing branch groups on the binary tree, which
yields in particular finitely generated branch groups with non-cyclic free subgroups. 相似文献
944.
Fix a smooth very ample curve C on a K3 or abelian surface X. Let $ \mathcal{M} $ denote the
moduli space of pairs of the form (F, s), where F is a stable sheaf over X whose Hilbert polynomial
coincides with that of the direct image, by the inclusion map of C in X, of a line bundle of degree d
over C, and s is a nonzero section of F. Assume d to be sufficiently large such that F has a nonzero
section. The pullback of the Mukai symplectic form on moduli spaces of stable sheaves over X is
a holomorphic 2-form on $ \mathcal{M} $. On the other hand, $ \mathcal{M} $ has a map to a Hilbert scheme parametrizing
0-dimensional subschemes of X that sends (F, s) to the divisor, defined by s, on the curve defined
by the support of F. We prove that the above 2-form on $ \mathcal{M} $ coincides with the pullback of the
symplectic form on the Hilbert scheme. 相似文献
945.
We give a simple proof of a theorem, due to Birkenmeier,
Kim and Park, which states that if $R[x, x^{-1}]$ or $R[[x, x^{-1}]]$ is
a quasi-Baer ring then R is a quasi-Baer ring.
Received: 8 April 2002 相似文献
946.
Further investigation into the properties of the Peirce-one space J1
corresponding to a weak*-closed inner ideal J in a JBW*-triple
A is carried out, and, in particular, it is shown that J1 contains
no non-trivial weak*-closed ideals.Received: 12 June 2002 相似文献
947.
948.
Igor Dolinka 《Algebra Universalis》2003,50(3-4):325-340
We give an equational characterization of (varieties of) semigroups having a
pn-sequence bounded above
by a polynomial function of n. This is achieved by studying
the syntactical connections between certain semigroup identities and their equational consequences. 相似文献
949.
J. N.?BarbosaEmail author A.?Brasil Jr.Email author é. A.?Costa I. C.?Lázaro 《Archiv der Mathematik》2003,81(3):335-341
In this paper we prove that a compact oriented hypersurface of a Euclidean
sphere with nonnegative Ricci curvature and infinite fundamental group is isometric
to an H(r)-torus
with constant mean curvature. Furthermore, we generalize, whithout any
hypothesis about the mean curvature, a characterization of Clifford torus due to
Hasanis and Vlachos.
Received: 19 March 2002 相似文献
950.
We characterize the Banach spaces enjoying polynomial lifting
properties, and the spaces that admit compact extensions of
polynomials.Received: 20 June 2002 相似文献