12,981 research outputs found
Equivariant Moore spaces and the Dade group
Let be a finite -group and be a field of characteristic . A
topological space is called an -Moore space if its reduced homology is
nonzero only in dimension . We call a -CW-complex an
-Moore -space over if for every subgroup of , the
fixed point set is an -Moore space with coefficients in
, where is a function of . We show that if is a
finite -Moore -space, then the reduced homology module of
is an endo-permutation -module generated by relative syzygies. A
-module is an endo-permutation module if is a permutation -module. We consider the Grothendieck group of
finite Moore -spaces , with addition given by the join
operation, and relate this group to the Dade group generated by relative
syzygies.Comment: 22 page
Existence of Equilibrium in Incomplete Markets with Non-Ordered Preferences
In this paper we extend the results of recent studies on the existence of equilibrium in finite dimensional asset markets for both bounded and unbounded economies. We do not assume that the individual's preferences are complete or transitive. Our existence theorems for asset markets allow for short selling. We shall also show that the equilibrium achieves a constrained core within the same framework.Equilibrium Existence, Incomplete Preferences, Incomplete Markets, Constrained Core
Constructing homologically trivial actions on products of spheres
We prove that if a finite group has a representation with fixity ,
then it acts freely and homologically trivially on a finite CW-complex homotopy
equivalent to a product of spheres. This shows, in particular, that every
finite group acts freely and homologically trivially on some finite CW-complex
homotopy equivalent to a product of spheres
Linear colorings of simplicial complexes and collapsing
A vertex coloring of a simplicial complex is called a linear
coloring if it satisfies the property that for every pair of facets of , there exists no pair of vertices with the same
color such that and . We
show that every simplicial complex which is linearly colored with
colors includes a subcomplex with vertices such that is
a strong deformation retract of . We also prove that this deformation
is a nonevasive reduction, in particular, a collapsing.Comment: 18 page
The proximity-concentration trade-off in a dynamic framework
This paper presents a dynamic framework which implements risk as a continuous variable into the proximity-concentration trade-of concept. Additionally firms have the possibility to postpone their investment decision which gives them the possibility to collect further information about the volatile variable over time. On the basis of the real option theory (Dixit and Pindyck, 1994) an investment plan under uncertainty is derived. In contrast to static models firms postpone their investment decision although positive returns can be achieved. For specific risk values the model predicts, in the presence of a foreign direct investment choice, the export strategy can be rejected although it is dominating the FDI project and although it is worthier than its option value. The results of the model undermine empirical findings which analyze the impact of continuous variables on export and FDI patterns. --export,FDI,uncertainty,real option approach
Homotopy Representations over the Orbit Category
Let G be a finite group. The unit sphere in a finite-dimensional orthogonal
G-representation motivates the definition of homotopy representations, due to
tom Dieck. We introduce an algebraic analogue, and establish its basic
properties including the Borel-Smith conditions and realization by finite
G-CW-complexes.Comment: 24 pages (revised for improved exposition). To appear in "Homology,
Homotopy and Applications". The sequel to this preprint is "Group actions on
spheres with rank one isotropy" (arXiv: 1302.0507
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