共查询到20条相似文献,搜索用时 13 毫秒
1.
Frank Sottile Thorsten Theobald 《Proceedings of the American Mathematical Society》2005,133(10):2835-2844
Let and denote the dimension and the degree of the Grassmannian , respectively. For each there are (a priori complex) -planes in tangent to general quadratic hypersurfaces in . We show that this class of enumerative problems is fully real, i.e., for there exists a configuration of real quadrics in (affine) real space so that all the mutually tangent -flats are real.
2.
Suppose that is a smooth -action on a closed smooth -dimensional manifold such that all Stiefel-Whitney classes of the tangent bundle to each connected component of the fixed point set vanish in positive dimension. This paper shows that if 2^k\dim F$"> and each -dimensional part possesses the linear independence property, then bounds equivariantly, and in particular, is the best possible upper bound of if is nonbounding.
3.
D. A. Redett 《Proceedings of the American Mathematical Society》2005,133(5):1459-1461
In this note, we give a new proof of the characterization of the -invariant subspaces of for in using ideas from approximation theory. 相似文献
4.
M. M. Popov 《Proceedings of the American Mathematical Society》2005,133(7):2023-2028
Let p_1 > p_2 > \cdots > 1$">. We construct an easily determined -symmetric basic sequence in , which spans a hereditarily subspace without the Schur property. An immediate consequence is the existence of hereditarily subspaces of without the Schur property.
5.
H. H. Edwards P. Mikusinski M. D. Taylor 《Proceedings of the American Mathematical Society》2005,133(5):1505-1513
A measure, , on is said to be -invariant if its value for any Borel set is invariant with respect to the symmetries of the unit square. A function, , generated in a certain way by a measure, , on is shown to be a measure of concordance if and only if the generating measure is positive, regular, -invariant, and satisfies certain inequalities. The construction examined here includes Blomqvist's beta as a special case.
6.
N. Anghel 《Proceedings of the American Mathematical Society》2005,133(8):2461-2467
We use separation of variables for generalized Dirac operators on rotationally symmetric Riemannian manifolds to recover a theorem of Dodziuk regarding the spaces of -harmonic forms on such manifolds.
7.
Alex N. Dranishnikov Yuli B. Rudyak 《Proceedings of the American Mathematical Society》2005,133(5):1557-1561
We construct closed -connected manifolds of dimensions that possess non-trivial rational Massey triple products. We also construct examples of manifolds such that all the cup-products of elements of vanish, while the group is generated by Massey products: such examples are useful for the theory of systols.
8.
Ian M. Aberbach 《Proceedings of the American Mathematical Society》2005,133(1):27-29
Let be an excellent local ring of positive prime characteristic. We show that if , then is regular. This improves a result of Schoutens, in which the additional hypothesis that was an isolated singularity was required for the proof.
9.
Brandt Kronholm 《Proceedings of the American Mathematical Society》2005,133(10):2891-2895
In the late 19th century, Sylvester and Cayley investigated the properties of the partition function . This function enumerates the partitions of a non-negative integer into exactly parts. Here we investigate the congruence properties of such functions and we obtain several infinite classes of Ramanujan-type congruences.
10.
D. A. Redett 《Proceedings of the American Mathematical Society》2005,133(9):2689-2695
In this note, we characterize certain algebraic subspaces of extending D. Singh's result.
11.
D. A. Redett 《Proceedings of the American Mathematical Society》2005,133(4):1151-1156
In this note we extend the ``Beurling type' characterizations of subspaces of and to and , respectively.
12.
T. S. S. R. K. Rao 《Proceedings of the American Mathematical Society》2005,133(9):2729-2732
In this paper we study the structure of local isometries on . We show that when is first countable and is uniformly convex and the group of isometries of is algebraically reflexive, the range of a local isometry contains all compact operators. When is also uniformly smooth and the group of isometries of is algebraically reflexive, we show that a local isometry whose adjoint preserves extreme points is a -module map.
13.
Michal Misiurewicz Ana Rodrigues 《Proceedings of the American Mathematical Society》2005,133(4):1109-1118
The famous problem involves applying two maps: and to positive integers. If is even, one applies , if it is odd, one applies . The conjecture states that each trajectory of the system arrives to the periodic orbit . In this paper, instead of choosing each time which map to apply, we allow ourselves more freedom and apply both and independently of . That is, we consider the action of the free semigroup with generators and on the space of positive real numbers. We prove that this action is minimal (each trajectory is dense) and that the periodic points are dense. Moreover, we give a full characterization of the group of transformations of the real line generated by and .
14.
We prove that for Hilbert space operators and , it follows that
where . Using the concept of -Gateaux derivative, we apply this result to characterize orthogonality in the sense of James in , and to give an easy proof of the characterization of smooth points in .
,\end{displaymath}">
where . Using the concept of -Gateaux derivative, we apply this result to characterize orthogonality in the sense of James in , and to give an easy proof of the characterization of smooth points in .
15.
Robert Fefferman Jill Pipher 《Proceedings of the American Mathematical Society》2005,133(11):3235-3241
We prove a covering lemma for rectangles in which has connections to a problem of Zygmund and its solution in three dimensions by Cordoba.
16.
Siu-Hung Ng 《Proceedings of the American Mathematical Society》2005,133(8):2237-2242
Let be a finite-dimensional Hopf algebra over an algebraically closed field of characteristic 0. If is not semisimple and for some odd integer , then or is not unimodular. Using this result, we prove that if for some odd prime , then is semisimple. This completes the classification of Hopf algebras of dimension .
17.
Masaharu Kusuda 《Proceedings of the American Mathematical Society》2005,133(11):3341-3344
Let and be -algebras and let be an --imprimitivity bimodule. Then it is shown that if the spectrum of (resp. of ) is discrete, then every closed --submodule of is orthogonally closed in , and conversely that if (resp. ) is a -space and if every closed --submodule of is orthogonally closed in , then (resp. ) is discrete.
18.
Gabriel Navarro Geoffrey R. Robinson 《Proceedings of the American Mathematical Society》2005,133(10):2845-2851
Let be a -block of a finite group . If is a -power for all , then is nilpotent.
19.
M. Raja 《Proceedings of the American Mathematical Society》2005,133(8):2395-2400
Let be a compact Hausdorff space and let be a lower semicontinuous metric on it. We prove that is fragmented by if, and only if, contains no copy of made up of Lipschitz functions with respect to . As applications we obtain a characterization of Asplund Banach spaces and Radon-Nikodým compacta.
20.
E. Batzies 《Proceedings of the American Mathematical Society》2007,135(10):3341-3347
We establish a homeomorphism between the moduli space of ordered -tuples of 2-dimensional linear subspaces (mod ) and the quotient by simultaneous conjugation of a certain open subset . For , this leads to an explicit computation of the moduli space of central 2-arrangements in mod and its subspace of those classes that contain a complex hyperplane arrangement.