共查询到20条相似文献,搜索用时 15 毫秒
1.
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$"> and each -dimensional part possesses the linear independence property, then bounds equivariantly, and in particular, is the best possible upper bound of if is nonbounding.
2.
Margherita Barile Gennady Lyubeznik 《Proceedings of the American Mathematical Society》2005,133(11):3199-3209
We describe a class of toric varieties which are set-theoretic complete intersections only over fields of one positive characteristic .
3.
Frank Sottile Thorsten Theobald 《Proceedings of the American Mathematical Society》2005,133(10):2835-2844
Let and denote the dimension and the degree of the Grassmannian , respectively. For each there are (a priori complex) -planes in tangent to general quadratic hypersurfaces in . We show that this class of enumerative problems is fully real, i.e., for there exists a configuration of real quadrics in (affine) real space so that all the mutually tangent -flats are real.
4.
In this paper, we give a weak classification of locally linear pseudofree actions of the cyclic group of order on a surface, and prove the existence of such an action which cannot be realized as a smooth action on the standard smooth surface.
5.
D. A. Redett 《Proceedings of the American Mathematical Society》2005,133(5):1459-1461
In this note, we give a new proof of the characterization of the -invariant subspaces of for in using ideas from approximation theory. 相似文献
6.
M. M. Popov 《Proceedings of the American Mathematical Society》2005,133(7):2023-2028
Let p_1 > p_2 > \cdots > 1$">. 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.
7.
John Erik Fornæ ss Nils Ø vrelid Sophia Vassiliadou 《Proceedings of the American Mathematical Society》2005,133(8):2377-2386
We obtain some -results for the operator on forms that vanish to high order on the singular set of a complex space.
8.
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.
9.
Florian Enescu 《Proceedings of the American Mathematical Society》2003,131(11):3379-3386
The notion of stability of the highest local cohomology module with respect to the Frobenius functor originates in the work of R. Hartshorne and R. Speiser. R. Fedder and K.-i. Watanabe examined this concept for isolated singularities by relating it to -rationality. The purpose of this note is to study what happens in the case of non-isolated singularities and to show how this stability concept encapsulates a few of the subtleties of tight closure theory. Our study can be seen as a generalization of the work by Fedder and Watanabe. We introduce two new ring invariants, the -stability number and the set of -stable primes. We associate to every ideal generated by a system of parameters and an ideal of multipliers denoted and obtain a family of ideals . The set is independent of and consists of finitely many prime ideals. It also equals prime ideal such that is -stable. The maximal height of such primes defines the -stability number.
10.
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.
11.
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.
12.
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.
13.
Peter Milley 《Proceedings of the American Mathematical Society》2005,133(10):3115-3120
If is a hyperbolic manifold and is a simple closed geodesic, then lifts to a collection of lines in acted upon by . In this paper we show that such a collection of lines cannot contain a particular type of subset (called a bad triple) unless has orientation-reversing elements. This fact allows us to extend certain lower bounds on hyperbolic volume to the non-orientable case.
14.
Jerzy Kakol Stephen A. Saxon Aaron R. Todd 《Proceedings of the American Mathematical Society》2004,132(6):1703-1712
Let be a completely regular Hausdorff space, and let be the space of continuous real-valued functions on endowed with the compact-open topology. We find various equivalent conditions for to be a -space, resolving an old question of Jarchow and consolidating work by Jarchow, Mazon, McCoy and Todd. Included are analytic characterizations of pseudocompactness and an example that shows that, for , Grothendieck's -spaces do not coincide with Jarchow's -spaces. Any such example necessarily answers a thirty-year-old question on weak barrelledness properties for , our original motivation.
15.
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.
16.
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 .
17.
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 .
18.
Grigory Mikhalkin 《Journal of the American Mathematical Society》2005,18(2):313-377
The paper establishes a formula for enumeration of curves of arbitrary genus in toric surfaces. It turns out that such curves can be counted by means of certain lattice paths in the Newton polygon. The formula was announced earlier in Counting curves via lattice paths in polygons, C. R. Math. Acad. Sci. Paris 336 (2003), no. 8, 629-634.
The result is established with the help of the so-called tropical algebraic geometry. This geometry allows one to replace complex toric varieties with the real space and holomorphic curves with certain piecewise-linear graphs there.
19.
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 .
20.
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.