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111.
In this article we extend the Miyashita–Ulbrich action for weak H-Galois extensions associated to a weak bialgebra H. Also, if H is a weak Hopf algebra, we prove that this action induces a monoidal connection with the category of right-right Yetter–Drinfeld modules over H. 相似文献
112.
Ákos Császár 《Acta Mathematica Hungarica》2005,108(4):351-354
Summary In the paper [5], several operations on generalized topologies are considered. They are not monotone in general, but an old result on monotonicity may be sharpened. 相似文献
113.
Daniel Girela José Ángel Peláez Fernando Pérez-González Jouni Rättyä 《Integral Equations and Operator Theory》2008,61(4):511-547
In this paper we study the positive Borel measures μ on the unit disc in for which the Bloch space is continuously included in , 0 < p < ∞. We call such measures p-Bloch-Carleson measures. We give two conditions on a measure μ in terms of certain logarithmic integrals one of which is a necessary condition and the other a sufficient condition for μ being a p-Bloch-Carleson measure. We also give a complete characterization of the p-Bloch-Carleson measures within certain special classes of measures. It is also shown that, for p > 1, the p-Bloch-Carleson measures are exactly those for which the Toeplitz operator , defined by , maps continuously into the Bergman space A
1, . Furthermore, we prove that if p > 1, α >-1 and ω is a weight which satisfies the Bekollé-Bonami -condition, then the measure defined by is a p-Bloch-Carleson-measure.
We also consider the Banach space of those functions f which are analytic in and satisfy , as . The Bloch space is contained in . We describe the p-Carleson measures for and study weighted composition operators and a class of integration operators acting in this space. We determine which of
these operators map continuously to the weighted Bergman space and show that they are automatically compact.
This research is partially supported by several grants from “the Ministerio de Educación y Ciencia, Spain” (MTM2005-07347,
MTM2007-60854, MTM2006-26627-E, MTM2007-30904-E and Ingenio Mathematica (i-MATH) No. CSD2006-00032); from “La Junta de Andalucía”
(FQM210 and P06-FQM01504); from “the Academy of Finland” (210245) and from the European Networking Programme “HCAA” of the
European Science Foundation. 相似文献
114.
We show that the complementary error function, $\text{erfc} (z)= \frac{2}{\sqrt{\pi}}\int_z^{\infty}{e^{-s^2} \text{d}s}$ , has no zeros in $\text{D}= \left\{ z : \frac{3}{4} \ \pi \le Arg z \le\frac{5}{4} \ \pi \right\}$ . 相似文献
115.
Given a basis for 2‐cocycles over a group G of order , we describe a nonlinear system of 4t‐1 equations and k indeterminates over , whose solutions determine the whole set of cocyclic Hadamard matrices over G, in the sense that ( ) is a solution of the system if and only if the 2‐cocycle gives rise to a cocyclic Hadamard matrix . Furthermore, the study of any isolated equation of the system provides upper and lower bounds on the number of coboundary generators in which have to be combined to form a cocyclic Hadamard matrix coming from a special class of cocycles. We include some results on the families of groups and . A deeper study of the system provides some more nice properties. For instance, in the case of dihedral groups , we have found that it suffices to check t instead of the 4t rows of , to decide the Hadamard character of the matrix (for a special class of cocycles f). © 2008 Wiley Periodicals, Inc. J Combin Designs 16: 276–290, 2008 相似文献
116.
Given a bipartite graph \(G = (A \cup B,E)\) with strict preference lists and given an edge \(e^* \in E\), we ask if there exists a popular matching in G that contains \(e^*\). We call this the popular edge problem. A matching M is popular if there is no matching \(M'\) such that the vertices that prefer \(M'\) to M outnumber those that prefer M to \(M'\). It is known that every stable matching is popular; however G may have no stable matching with the edge \(e^*\). In this paper we identify another natural subclass of popular matchings called “dominant matchings” and show that if there is a popular matching that contains the edge \(e^*\), then there is either a stable matching that contains \(e^*\) or a dominant matching that contains \(e^*\). This allows us to design a linear time algorithm for identifying the set of popular edges. When preference lists are complete, we show an \(O(n^3)\) algorithm to find a popular matching containing a given set of edges or report that none exists, where \(n = |A| + |B|\). 相似文献
117.
Álvaro Meseguer 《Theoretical and Computational Fluid Dynamics》2002,16(1):71-77
This work is devoted to the study of transient growth of perturbations in the Taylor–Couette problem due to linear nonnormal
mechanisms. The study is carried out for a particular small gap case and is mostly focused on the linearly stable regime of
counter-rotation. The exploration covers a wide range of inner and outer angular speeds as well as axial and azimuthal modes.
Significant transient growth is found in the regime of stable counter-rotation. The numerical results are in agreement with
former analyses based on energy methods and other independent numerical studies. The optimal energy transient growth factor
appears to be consistent with experimental observations. This study might shed some light on the subcritical transition to
turbulence which is found experimentally in Taylor–Couette flow when the cylinders rotate in opposite directions.
Received 13 February 2001 and accepted 29 March 2002 Published online: 2 October 2002
RID="*"
ID="*" This work was supported by the UK EPSRC under Grant GR/M30890. The author thanks Nick Trefethen for fruitful discussions.
RID="*"
ID="*" Present address: Departament de Fisica Aplicada, Univ. Politecnica de Catalunya, 08034 Barcelona, Spain (alvar@fa.upc.es)
Communicated by H.J.S. Fernando 相似文献
118.
JOSEF MÁLEK JINDŘICH NEČAS K. R. RAJAGOPAL 《Archive for Rational Mechanics and Analysis》2002,165(3):243-269
To describe the flows of fluids over a wide range of pressures, it is necessary to take into account the fact that the viscosity
of the fluid depends on the pressure. That the viscosity depends on the pressure has been verified by numerous careful experiments.
While the existence of solutions local-in-time to the equations governing the flows of such fluids are available for small,
special data and rather unrealistic dependence of the viscosity on the pressure, no global existence results are in place.
Our interest here is to establish the existence of weak solutions for spatially periodic three-dimensional flows that are
global in time, for a large class of physically meaningful viscosity-pressure relationships.
(Accepted May 1, 2002) Published online November 15, 2002
Communicated by S. S. ANTMAN 相似文献
119.
To illustrate vertical and horizontal equidistributions of Kloosterman sums, we prove two relevant central limit theorems by some analytic and combinatorial properties of Chebyshev polynomials and independence of monodromy groups of Kloosterman sheaves. The first one supports a short interval version of Katz’s vertical Sato–Tate distribution theorem, and the second one coincides with the horizontal conjecture of Katz in the statistical sense. 相似文献
120.
Auer Peter Dósa György Dulai Tibor Fügenschuh Armin Näser Peggy Ortner Ronald Werner-Stark Ágnes 《Central European Journal of Operations Research》2021,29(3):1079-1113
Central European Journal of Operations Research - We deal with a very complex and hard scheduling problem. Two types of products are processed by a heterogeneous resource set, where resources have... 相似文献