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31.
Tarig Abdelgadir 《代数通讯》2013,41(2):636-649
We describe weighted projective lines in the sense of Geigle and Lenzing by a moduli problem on the canonical algebra of Ringel. We then go on to study generators of the derived categories of coherent sheaves on the total spaces of their canonical bundles, and show that they are rarely tilting. We also give a moduli construction for these total spaces for weighted projective lines with three orbifold points. 相似文献
32.
There are only finitely many locally projective regular polytopes of type {5, 3, 5}. They are covered by a locally spherical polytope whose automorphism group is J1×J1×L2(19), where J1 is the first Janko group, of order 175560, and L2(19) is the projective special linear group of order 3420. This polytope is minimal, in the sense that any other polytope that covers all locally projective polytopes of type {5, 3, 5} must in turn cover this one. 相似文献
33.
We can describe higher-dimensional classical spaces by analytical projective geometry, if we embed the d-dimensional real space onto a d + 1-dimensional real projective metric vector space. This method allows an approach to Euclidean, hyperbolic, spherical and
other geometries uniformly [8].
To visualize d-dimensional solids, it is customary to make axonometric projection of them. In our opinion the central projection gives more
information about these objects, and it contains the axonometric projection as well, if the central figure is an ideal point
or an s-dimensional subspace at infinity. We suggest a general method which can project solids into any picture plane (space) from
any central figure, complementary to the projection plane (space). Opposite to most of the other algorithms in the literature,
our algorithm projects higher-dimensional solids directly into the two-dimensional picture plane (especially into the computer
screen), it does not use the three-dimensional space for intermediate step.
Our algorithm provides a general, so-called lexicographic visibility criterion in Definition and Theorem 3.4, so it determines
an extended visibility of the d-dimensional solids by describing the edge framework of the two-dimensional surface in front of us. In addition we can move
the central figure and the image plane of the projection, so we can simulate the moving position of the observer at fixed
objects on the computer screen (see first our figures in reverse order).
Supported by DAAD 2008 Multimedia Technology for Mathematics and Computer Science Education. 相似文献
34.
In this paper, we study the central limit theorem and its weak invariance principle for sums of a stationary sequence of random
variables, via a martingale decomposition. Our conditions involve the conditional expectation of sums of random variables
with respect to the distant past. The results contribute to the clarification of the central limit question for stationary
sequences.
Magda Peligrad is supported in part by a Charles Phelps Taft research support grant at the Univeristy of Cincinnati and the
NSA grant H98230-05-1-0066. 相似文献
35.
L. L. Maksimova 《Algebra and Logic》2006,45(1):49-66
We look at the interplay between the projective Beth property in non-classical logics and interpolation. Previously, we proved
that in positive logics as well as in superintuitionistic and modal ones, the projective Beth property PB2 follows from Craig's interpolation property and implies the restricted interpolation property IPR. Here, we show that IPR and PB2 are equivalent in positive logics, and also in extensions of the superintuitionistic logic KC and of the modal logic Grz.2.
Supported by RFBR grant No. 06-01-00358, by INTAS grant No. 04-77-7080, and by the Council for Grants (under RF President)
and State Aid of Fundamental Science Schools, project NSh-2069.2003.1.
__________
Translated from Algebra i Logika, Vol. 45, No. 1, pp. 85–113, January–February, 2006. 相似文献
36.
Jiří M. Tomáš 《Czechoslovak Mathematical Journal》2006,56(4):1131-1145
37.
任意一个弱分段Koszul模M都被证明存在一个自然的分次子模链0=U0(?)U1(?)U2(?)…(?) Ut=M使得每个商Ui/Ui-1都是分段Koszul模.本文的主要目的是建立M和Ui/Ui-1的极小分次投射解之间的关系.对n≥0,证明了Pn=⊕i=1t Pni,其中P*i→Ui/Ui-1→0和P*→M→0是相应的极小分次投射解,作为其直接推论,有pd(M)=max{pd(Ui/Ui-1)}成立. 相似文献
38.
This article proves the existence of singular directions of value distribution theory for some transcendental holomorphic curves in the n-dimensional complex projective space Pn(C). An example is given to complement these results. 相似文献
39.
Jinjia Li 《Proceedings of the American Mathematical Society》2006,134(5):1271-1275
Let be a finitely generated module over a local complete intersection of characteristic . The property that has finite projective dimension can be characterized by the vanishing of for some and for some .
40.
Khalid KOUFANY 《数学学报(英文版)》2006,22(5):1467-1472
Let Ω be a symmetric cone. In this note, we introduce Hilbert's projective metric on Ω in terms of Jordan algebras and we apply it to prove that, given a linear invertible transformation g such that g(Ω) = Ω and a real number p, |p| 〉 1, there exists a unique element x ∈ Ω satisfying g(x) = x^p. 相似文献