共查询到20条相似文献,搜索用时 46 毫秒
1.
David A. Jorgensen 《Proceedings of the American Mathematical Society》1999,127(6):1575-1582
Let be a commutative Noetherian local ring, and let where is a non-zerodivisor of contained in . Then a finitely generated -module is said to lift to if there exists a finitely generated -module such that is -regular and . In this paper we give a general construction of finitely generated -modules of finite projective dimension over which fail to lift to provided and the depth of is at least 2.
2.
Nobuhiko Fujii Akihiro Nakamura Ray Redheffer 《Proceedings of the American Mathematical Society》1999,127(6):1815-1818
For let be complex numbers such that is bounded. For define , where . Then the excesses in the sense of Paley and Wiener satisfy .
3.
We study real algebraic morphisms from nonsingular real algebraic varieties with into nonsingular real algebraic curves . We show, among other things, that the set of real algebraic morphisms from into is never dense in the space of all maps from into , unless is biregularly isomorphic to a Zariski open subset of the unit circle.
4.
Franklin Mendivil 《Proceedings of the American Mathematical Society》1999,127(6):1863-1871
We provide some conditions as to when for two locally compact spaces and (where is the lattice of all Hausdorff compactifications of ). More specifically, we prove that if and only if . Using this result, we prove several extensions to the case where is embedded as a sub-lattice of and to where and are not locally compact.
One major contribution is in the use of function algebra techniques. The use of these techniques makes the extensions simple and clean and brings new tools to the subject.
5.
William G. Dwyer Emmanuel Dror Farjoun Douglas C. Ravenel 《Proceedings of the American Mathematical Society》1999,127(6):1855-1861
Let be a finitely generated nilpotent group. The object of this paper is to identify the Bousfield localization of the classifying space with respect to a multiplicative complex oriented homology theory . We show that is the same as the localization of with respect to the ordinary homology theory determined by the ring .
6.
For a nowhere constant continuous function on a real interval and for a Borel measure on , we give simple necessary and sufficient conditions guaranteeing, for any Borel function on , the existence of a continuous function on such that the derivative of with respect to is, almost everywhere, equal to .
7.
Greg Hjorth 《Proceedings of the American Mathematical Society》1999,127(1):271-278
Let be a Polish group, a Polish topology on a space , acting continuously on , with -invariant and in the Borel algebra generated by . Then there is a larger Polish topology on so that is open with respect to , still acts continuously on , and has a basis consisting of sets that are of the same Borel rank as relative to .
8.
T. Lachand-Robert M. A. Peletier 《Proceedings of the American Mathematical Society》1999,127(6):1723-1727
We investigate the extremal points of a functional , for a convex or concave function . The admissible functions are convex themselves and satisfy a condition . We show that the extremal points are exactly and if these functions are convex and coincide on the boundary . No explicit regularity condition is imposed on , , or . Subsequently we discuss a number of extensions, such as the case when or are non-convex or do not coincide on the boundary, when the function also depends on , etc.
9.
Mahan Mitra 《Proceedings of the American Mathematical Society》1999,127(6):1625-1631
Let be an exact sequence of hyperbolic groups induced by an automorphism of the free group . Let be a finitely generated distorted subgroup of . Then there exist and a free factor of such that the conjugacy class of is preserved by and contains a finite index subgroup of a conjugate of . This is an analog of a theorem of Scott and Swarup for surfaces in hyperbolic 3-manifolds.
10.
Let be a non-trivial finite Galois extension of a field . In this paper we investigate the role that valuation-theoretic properties of play in determining the non-triviality of the relative Brauer group, , of over . In particular, we show that when is finitely generated of transcendence degree 1 over a -adic field and is a prime dividing , then the following conditions are equivalent: (i) the -primary component, , is non-trivial, (ii) is infinite, and (iii) there exists a valuation of trivial on such that divides the order of the decomposition group of at .
11.
L. Mattner 《Proceedings of the American Mathematical Society》1999,127(6):1847-1854
There exists an asymmetric probability measure on the real line with for every . can be chosen absolutely continuous and can be chosen to be concentrated on the integers. In both cases, can be chosen to have moments of every order, but cannot be determined by its moments.
12.
Nathan S. Feldman 《Proceedings of the American Mathematical Society》1999,127(9):2685-2695
We shall use a -algebra approach to study operators of the form where is subnormal and is normal. We shall determine the spectral properties for these operators, and find the minimal normal extension and the dual operator. We also give a necessary condition for to contain a compact operator and a sufficient condition for the algebraic equivalence of and .
We also consider the existence of a homomorphism satisfying . We shall characterize the operators such that exists for every operator .
The problem of when is unitarily equivalent to is considered. Complete results are given when and are positive operators with finite multiplicity functions and has compact self-commutator. Some examples are also given.
13.
Y. Bahturin A. Giambruno M. Zaicev 《Proceedings of the American Mathematical Society》1999,127(1):63-69
Let be an algebra over a field and a finite group of automorphisms and anti-automorphisms of . We prove that if satisfies an essential -polynomial identity of degree , then the -codimensions of are exponentially bounded and satisfies a polynomial identity whose degree is bounded by an explicit function of . As a consequence we show that if is an algebra with involution satisfying a -polynomial identity of degree , then the -codimensions of are exponentially bounded; this gives a new proof of a theorem of Amitsur stating that in this case must satisfy a polynomial identity and we can now give an upper bound on the degree of this identity.
14.
D. W. B. Somerset 《Proceedings of the American Mathematical Society》1999,127(5):1379-1385
Let be a TAF-algebra, the centre of the ideal lattice of , and the space of meet-irreducible elements of , equipped with the hull-kernel topology. It is shown that is a compact, locally compact, second countable, -space, that is an algebraic lattice isomorphic to the lattice of open subsets of , and that is isomorphic to the algebra of continuous, complex functions on . If is semisimple, then is isomorphic to the algebra of continuous, complex functions on , the primitive ideal space of . If is strongly maximal, then the sum of two closed ideals of is closed.
15.
Yuan-chung Sheu 《Proceedings of the American Mathematical Society》1999,127(12):3721-3728
Consider an -superdiffusion on , where is an uniformly elliptic differential operator in , and . The -polar sets for are subsets of which have no intersection with the graph of , and they are related to the removable singularities for a corresponding nonlinear parabolic partial differential equation. Dynkin characterized the -polarity of a general analytic set in term of the Bessel capacity of , and Sheu in term of the restricted Hausdorff dimension. In this paper we study in particular the -polarity of sets of the form , where and are two Borel subsets of and respectively. We establish a relationship between the restricted Hausdorff dimension of and the usual Hausdorff dimensions of and . As an application, we obtain a criterion for -polarity of in terms of the Hausdorff dimensions of and , which also gives an answer to a problem proposed by Dynkin in the 1991 Wald Memorial Lectures.
16.
Zhi-Wei Sun 《Proceedings of the American Mathematical Society》1999,127(5):1293-1300
Let be a system of arithmetic sequences which forms an -cover of (i.e. every integer belongs at least to members of ). In this paper we show the following surprising properties of : (a) For each there exist at least subsets of with such that . (b) If forms a minimal -cover of , then for any there is an such that for every there exists an for which and
17.
E. Ballico R. M. Miró -Roig 《Proceedings of the American Mathematical Society》1999,127(9):2557-2560
Fix a smooth projective 3-fold , , with ample, and . Assume the existence of integers with such that is numerically equivalent to . Let be the moduli scheme of -stable rank 2 vector bundles, , on with and . Let be the number ofits irreducible components. Then .
18.
Victor Tan 《Proceedings of the American Mathematical Society》1999,127(10):2811-2820
Let and be the pair of unitary groups over a global field and an irreducible cuspidal representation of which satisfies a certain -function condition. By using a regularized Siegel-Weil formula, we can show that the global theta lifting of in is non-trivial if every local factor of has a local theta lifting (Howe lifting) in .
19.
Yakov Berkovich 《Proceedings of the American Mathematical Society》1999,127(9):2505-2509
For a prime divisor of the order of a finite group , we present the set of -subgroups generating . In particular, we present the set of primary subgroups of generating the last member of the lower central series of . The proof is based on the Frobenius Normal -Complement Theorem and basic properties of minimal nonnilpotent groups. Let be a group and a group-theoretic property inherited by subgroups and epimorphic images such that all minimal non--subgroups (-subgroups) of are not nilpotent. Then (see the lemma), if is generated by all -subgroups of it follows that is a -group.
20.
Abdelaziz Maouche 《Proceedings of the American Mathematical Society》1999,127(11):3187-3190
Given two semisimple complex Jordan-Banach algebras with identity and , we say that is a spectrum preserving linear mapping from to if is surjective and we have , for all . We prove that if is a scattered Jordan-Banach algebra, then is a Jordan isomorphism.