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1.
We construct a self-avoiding process taking values in the finite Sierpinski gasket, and study its properties. We then study continuum limit processes that are suggested by the statistical mechanics of self-avoiding paths on the pre-Sierpinski gasket. We prove that there are three types of continuum limit processes according to the parameters defining the statistical mechanics of self-avoiding paths:
(i)  the self-avoiding process we construct in this paper;
(ii)  a deterministic motion along a Peano curve on the finite Sierpinski gasket;
(iii)  a deterministic motion along a line segment.
  相似文献   

2.
Following our approach to metric Lie algebras developed in a previous paper we propose a way of understanding pseudo-Riemannian symmetric spaces which are not semisimple. We introduce cohomology sets (called quadratic cohomology) associated with orthogonal modules of Lie algebras with involution. Then we construct a functorial assignment which sends a pseudo-Riemannian symmetric space M to a triple consisting of:
  (i) a Lie algebra with involution (of dimension much smaller than the dimension of the transvection group of M);
  (ii) a semisimple orthogonal module of the Lie algebra with involution; and
  (iii) a quadratic cohomology class of this module.
That leads to a classification scheme of indecomposable nonsimple pseudo-Riemannian symmetric spaces. In addition, we obtain a full classification of symmetric spaces of index 2 (thereby completing and correcting in part earlier classification results due to Cahen and Parker and to Neukirchner).  相似文献   

3.
We study several kinds of distributivity for concept lattices of contexts. In particular, we find necessary and sufficient conditions for a concept lattice to be
(1)  distributive,
(2)  a frame (locale, complete Heyting algebra),
(3)  isomorphic to a topology,
(4)  completely distributive,
(5)  superalgebraic (i.e., algebraic and completely distributive).
In cases (2), (4) and (5), our criteria are first order statements on objects and attributes of the given context. Several applications are obtained by considering the completion by cuts and the completion by lower ends of a quasiordered set as special types of concept lattices. Various degrees of distributivity for concept lattices are expressed by certain separation axioms for the underlying contexts. Passing to complementary contexts makes some statements and proofs more elegant. For example, it leads to a one-to-one correspondence between completely distributive lattices and so-called Cantor lattices, and it establishes an equivalence between partially ordered sets and doubly founded reduced contexts with distributive concept lattices.  相似文献   

4.
LetF(X, Y) be a two dimensional polynomial map overC. We show how to use the notion of induced resultants in order to give short and elementary proofs to the following three theorems:
1.  If the Jacobian of F is a non-zero constant, then the image of F contains all of C2 except for a finite set.
2.  If F is invertible, then the inverse map is determined by the free terms of the induced resultants.
3.  If F is invertible, then the degree of F equals the degree of its inverse.
  相似文献   

5.
Rings over which every nonzero right module has a maximal submodule are calledright Bass rings. For a ringA module-finite over its centerC, the equivalence of the following conditions is proved:
(1)  A is a tight Bass ring;
(2)  A is a left Bass ring;
(3)  A/J(A) is a regular ring, andJ(A) is a right and leftt-nilpotent ideal.
Translated fromMatematicheskie Zametki, Vol. 64, No. 1, pp. 136–142, July, 1998.This research was partially supported by the Russian Foundation for Basic Research under grant No. 96-01-00627.  相似文献   

6.
We have generalized the theory of Shannon's games in [10]. In this paper, we treat a game on a graph with an action of elementary abelian group but our decision of the winner is more general. Our theory can be applied for non-negative integersn andr, to the two games on a graph withn + 1 distinguished terminals whose rules are as follows:
(1)  the players Short and Cut play alternately to choose an edge,
(2)  the former contracts it and the later deletes it
(3)  the former if and only if he connects the terminals into at mostn – r + 1 ones.
Dedicated to Professor Sin Hitotumatu for his 60'th birthday  相似文献   

7.
We consider games in coalition function form on a, generally infinite, algebra of coalitions. For finite algebras the additive part mappingv E(v ¦) is the usual. The concern here is the analogue for infinite algebras. The useful construction is the finitely additive stochastic process of additive parts of the game on the filtration f of finite subalgebras of.It is shown that is an isomorphism between:
a)  Additive games and martingales
b)  Superadditive games and supermartingales
c)  Shapley's games of bounded deviationBD() in his (1953) dissertation and bounded F-processes of Armstrong (1983)
d)  Gilboa's spaceBS() (1989) and bounded processes of Armstrong (1983)
  相似文献   

8.
In this paper, we discuss the representation-finite selfinjective artin algebras of classB n andC n and obtain the following main results: For any fieldk, let Λ be a representation-finite selfinjective artin algebras of classB n orC n overk.
(a)  We give the configuration ofZB n andZC n.
(b)  We show that Λ is standard.
(c)  Under the condition ofk being a perfect field, we describe Λ by boundenk-species and show that Λ is a finite covering of the trivial extension of some tilted algebra of typeB n orC n.
  相似文献   

9.
We develop the theory of “branch algebras”, which are infinite-dimensional associative algebras that are isomorphic, up to taking subrings of finite codimension, to a matrix ring over themselves. The main examples come from groups acting on trees. In particular, for every field % MathType!End!2!1! we contruct a % MathType!End!2!1! which
–  • is finitely generated and infinite-dimensional, but has only finitedimensional quotients;
–  • has a subalgebra of finite codimension, isomorphic toM 2(k);
–  • is prime;
–  • has quadratic growth, and therefore Gelfand-Kirillov dimension 2;
–  • is recursively presented;
–  • satisfies no identity;
–  • contains a transcendental, invertible element;
–  • is semiprimitive if % MathType!End!2!1! has characteristic ≠2;
–  • is graded if % MathType!End!2!1! has characteristic 2;
–  • is primitive if % MathType!End!2!1! is a non-algebraic extension of % MathType!End!2!1!;
–  • is graded nil and Jacobson radical if % MathType!End!2!1! is an algebraic extension of % MathType!End!2!1!.
The author acknowledges support from TU Graz and UC Berkeley, where part of this research was conducted.  相似文献   

10.
We show that all projective resolutions over a monomial relations algebra Λ simplify drastically at the stage of the second syzygy; more precisely, we show that the kernel of any homomorphism between two projective left Λ-modules is isomorphic to a direct sum of principal left ideals generated by paths. As consequences, we obtain:
(a)  a tight approximation of the finitistic dimensions of Λ in terms of the (very accessible) projective dimensions of the principal left ideals generated by paths;
(b)  a basis for comparison of the ‘big’ and ‘little’ finitistic dimensions of Λ, yielding in particular that these two invariants cannot differ by more than 1 and that they are equal in ‘most’ cases;
(c)  manageable algorithms for computation of finitistic dimensions.
This research was partially supported by a grant from the National Science Foundation.  相似文献   

11.
Continuing earlier work on construction of harmonic spaces from translation invariant Dirichlet spaces defined on locally compact abelian groups, it is shown that the potential kernel for a non-symmetric translation invariant Dirichlet form on a locally compact abelian group under the extra assumptions that
(i)  the potential kernel is absolutely continuous and the canonical l.s.c. density is continuous in the complement of the neutral element.
(ii)  the theory is of local type.
(iii)  the underlying group is not discrete, can be interpreted as the potential kernel for a translation invariant axiomatic theory of harmonic functions, in which (among other properties) the domination axiom is fulfilled.
  相似文献   

12.
We consider smooth non-degenerate surfaces in ℙ4, and prove that there is a finite number of such surfaces which are:
(a)  sectionally non-special, i.e.h1(O C(1))=0, where C is a general hyperplane section of S; or
(b)  not of general type and non-special (i.e. h1(O C(1))=0.
A complete list is given in both cases.  相似文献   

13.
We discuss three scalarizations of the multiobjectie optimization from the point of view of the parametric optimization. We analyze three important aspects:
i)  What kind of singularities may appear in the different parametrizations
ii)  Regularizations in the sense of Jongen, Jonker and Twilt, and in the sense of Kojima and Hirabayashi.
iii)  The Mangasarian-Fromovitz Constraint Qualification for the first parametrization.
This paper is a short version of the thesis of the author at the University of Havanna, Department of Mathematics Havanna, Cuba.  相似文献   

14.
We present a new pivot-based algorithm which can be used with minor modification for the enumeration of the facets of the convex hull of a set of points, or for the enumeration of the vertices of an arrangement or of a convex polyhedron, in arbitrary dimension. The algorithm has the following properties:
(a)  Virtually no additional storage is required beyond the input data.
(b)  The output list produced is free of duplicates.
(c)  The algorithm is extremely simple, requires no data structures, and handles all degenerate cases.
(d)  The running time is output sensitive for nondegenerate inputs.
(e)  The algorithm is easy to parallelize efficiently.
For example, the algorithm finds thev vertices of a polyhedron inR d defined by a nondegenerate system ofn inequalities (or, dually, thev facets of the convex hull ofn points inR d, where each facet contains exactlyd given points) in timeO(ndv) andO(nd) space. Thev vertices in a simple arrangement ofn hyperplanes inR d can be found inO(n 2 dv) time andO(nd) space complexity. The algorithm is based on inverting finite pivot algorithms for linear programming.  相似文献   

15.
The star unfolding of a convex polytope with respect to a pointx on its surface is obtained by cutting the surface along the shortest paths fromx to every vertex, and flattening the surface on the plane. We establish two main properties of the star unfolding:
1.  It does not self-overlap: it is a simple polygon.
2.  The ridge tree in the unfolding, which is the locus of points with more than one shortest path fromx, is precisely the Voronoi diagram of the images ofx, restricted to the unfolding.
These two properties permit conceptual simplification of several algorithms concerned with shortest paths on polytopes, and sometimes a worst-case complexity improvement as well:
•  The construction of the ridge tree (in preparation for shortest-path queries, for instance) can be achieved by an especially simpleO(n 2) algorithm. This is no worst-case complexity improvement, but a considerable simplification nonetheless.
•  The exact set of all shortest-path “edge sequences” on a polytope can be found by an algorithm considerably simpler than was known previously, with a time improvement of roughly a factor ofn over the old bound ofO(n 7 logn).
•  The geodesic diameter of a polygon can be found inO(n 9 logn) time, an improvement of the previous bestO(n 10) algorithm.
  相似文献   

16.
Let X be a weakly Lindel?f determined Banach space. We prove that the following two statements are equivalent:
(i)  Every Radon probability measure on (BX*, w*) has separable support.
(ii)  Every countably additive X*-valued measure with σ-finite variation has norm separable range.
Some applications and related examples are given. Received: 11 January 2006; Revised: 24 May 2006  相似文献   

17.
Let (G, τ) be a commutative Hausdorff locally solid lattice group. In this paper we prove the following:
(1)  If (G, τ) has the A(iii)-property, then its completion is an order-complete locally solid lattice group.
(2)  If G is order-complete and τ has the Fatou property, then the order intervals of G are τ-complete.
(3)  If (G, τ) has the Fatou property, then G is order-dense in Ĝ and has the Fatou property.
(4)  The order-bound topology on any commutative lattice group is the finest locally solid topology on it.
As an application, a version of the Nikodym boundedness theorem for set functions with values in a class of locally solid topological groups is established.  相似文献   

18.
A family of complementarity problems is defined as extensions of the well-known linear complementarity problem (LCP). These are:
(i)  second linear complementarity problem (SLCP), which is an LCP extended by introducing further equality restrictions and unrestricted variables;
(ii)  minimum linear complementarity problem (MLCP), which is an LCP with additional variables not required to be complementary and with a linear objective function which is to be minimized;
(iii)  second minimum linear complementarity problem (SMLCP), which is an MLCP, but the nonnegative restriction on one of each pair of complementary variables is relaxed so that it is allowed to be unrestricted in value.
A number of well-known mathematical programming problems [namely, quadratic programming (convex, nonconvex, pseudoconvex, nonconvex), linear variational inequalities, bilinear programming, game theory, zero-one integer programming, fixed-charge problem, absolute value programming, variable separable programming] are reformulated as members of this family of four complementarity problems. A brief discussion of the main algorithms for these four problems is presented, together with some computational experience.  相似文献   

19.
For the Azimi-Hagler spaces more geometric and topological properties are investigated. Any constructed space is denoted by X α,p . We show
(i)  The subspace [(e nk )] generated by a subsequence (e nk ) of (e n ) is complemented.
(ii)  The identity operator from X α,p to X α,p when p > q is unbounded.
(iii)  Every bounded linear operator on some subspace of X α,p is compact. It is known that if any X α,p is a dual space, then
(iv)  duals of X α,1 spaces contain isometric copies of and their preduals contain asymptotically isometric copies of c 0.
(v)  We investigate the properties of the operators from X α,p spaces to their predual.
  相似文献   

20.
The paper deals with three related issues.
1.  It introduces a measure of partial subgame perfection for equilibria of repeated games.
2.  It illustrates that the folk-theorem discontinuity generated by small complexity costs, as exhibited by Abreu and Rubinstein, does not exist in the presence of any level of perfection.
3.  It shows that reactive strategy equilibria, such as tit-for-tat, cannot be subgame perfect, even partially so. As a corollary, this shows a need to use full automata rather than exact automata when studying complexity and perfection in repeated games.
This work was done while this author was visiting at the Department of Managerial Economics and Decision Sciences, J. L. Kellogg Graduate School of Management, Northwestern University.  相似文献   

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