1,049 research outputs found
The Regularity Problem for Lie Groups with Asymptotic Estimate Lie Algebras
We solve the regularity problem for Milnor's infinite dimensional Lie groups
in the asymptotic estimate context. Specifically, let be a Lie group with
asymptotic estimate Lie algebra , and denote its evolution map by
, i.e., . We show that
is -continuous on if and only if is
-continuous on . We furthermore
show that is k-confined for
if is constricted. (The latter condition is slightly less restrictive than
to be asymptotic estimate.) Results obtained in a previous paper then imply
that an asymptotic estimate Lie group is -regular if and only if
it is Mackey complete, locally -convex, and has Mackey complete Lie
algebra - In this case, is -regular for each (with ``smoothness restrictions'' for
), as well as -regular if is even sequentially
complete with integral complete Lie algebra.Comment: 27 pages. Version as published at Indagationes Mathematicae (title
refined; presentation improved; proof of Lemma 9 revised
A Characterization of Invariant Connections
Given a principal fibre bundle with structure group , and a fibre
transitive Lie group of automorphisms thereon, Wang's theorem identifies
the invariant connections with certain linear maps . In the present paper, we prove an
extension of this theorem which applies to the general situation where acts
non-transitively on the base manifold. We consider several special cases of the
general theorem, including the result of Harnad, Shnider and Vinet which
applies to the situation where admits only one orbit type. Along the way,
we give applications to loop quantum gravity
Regularity of Lie Groups
We solve the regularity problem for Milnor's infinite dimensional Lie groups
in the -topological context, and provide necessary and sufficient
regularity conditions for the standard setting (-topology). We prove that
the evolution map is -continuous on its domain
the Lie group is locally -convex. We furthermore show that if the
evolution map is defined on all smooth curves, then is Mackey complete -
This is a completeness condition formulated in terms of the Lie group
operations that generalizes Mackey completeness as defined for locally convex
vector spaces. Then, under the presumption that is locally -convex, we
show that each -curve, for , is integrable (contained in the domain of the
evolution map) is Mackey complete and
-confined. The latter condition states that each -curve in the
Lie algebra of can be uniformly approximated by a special
type of sequence consisting of piecewise integrable curves - A similar result
is proven for the case ; and we provide several mild conditions that
ensure that is -confined for each . We finally discuss the
differentiation of parameter-dependent integrals in the standard topological
context. In particular, we show that if the evolution map is well defined and
continuous on for ,
then it is smooth thereon is
Mackey complete for
integral complete for . This result is
obtained by calculating the directional derivatives explicitly - recovering the
standard formulas that hold in the Banach case.Comment: 72 pages. Revised version: notations simplified; oversights
corrected; example added to Sect. 3.5.2; Lemma 40 (now Lemma 13) shifted into
Sect. 3.5.4; Lipschitz case added to Lemma 23 (now Lemma 24); proof of Lemma
25 (now Lemma 26) revised; Proposition 6 correcte
Decompositions of Analytic 1-Manifolds
In a previous paper, connected analytic 1-dimensional submanifolds with
boundary have been classified w.r.t. their symmetry under a given regular Lie
group action on an analytic manifold. It was shown that each such submanifold
is either free or analytically diffeomorphic to the unit circle or some
interval via the exponential map. In this paper, we show that each free
connected analytic 1-submanifold naturally splits into symmetry free segments,
mutually and uniquely related by the group action. This is proven under the
assumption that the action is non-contractive, which is even less restrictive
than regularity.Comment: 25 page
Heterogeneity and Evolutionary Change - Empirical Conception, Findings and Unresolved Issues
In this position paper we deal with the conception of heterogeneity as both the force and the result of evolutionary change. We ask, how this heterogeneity can be measured empirically and how we can get a measure which allows to get a broad comparable empirical account especially on several levels of aggregation. Based on this discussion we suggest that for several questions the measures of total factor productivity (TFP) and local changes of TFP seem to be acceptable candidates for measuring heterogeneity and its dynamics. Examples out of a number of empirical investigations applying this measures show how interesting empirical facts about evolutionary change on several levels of aggregation can be detected. The paper concludes by raising a number of unresolved issues mainly related to the question about the relationship between evolutionary dynamics on several levels of aggregation.
Recent Trends in the Research on National Innovation Systems
In this paper, we give an overview on recent developments in the research on national innovation systems (NIS). Essentially, we identify three development lines of the concept. These are policy-oriented studies that frequently combine the NIS approach with the terminology of corporate benchmarking, contributions to formalize the concept of NIS through descriptive or analytical models, and NIS studies of countries beyond the group of highly industrialized economies. It follows from the analysis of these research trends that the concept has developed in distinctive directions. In international comparisons of innovation systems, heterogeneity in the structure of the systems is only marginally taken into account, an aspect that may reduce the explanatory power of such system-level comparisons. Contrary to this, historically grown organizational and institutional structures are extensively described and considered in NIS studies of industrializing countries, a characteristic which ties up with early studies of national innovation systems.innovation, national innovation systems, comparative studies
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