152 research outputs found
Moves towards Authentic Freedom. Church and State in Switzerland, and Beyond
Many of the Swiss Cantons have regulated the relations between church and state by establishing, in their public law, corporations at the levels of the municipality and of the canton. The role and the rights of these corporations, especially obligatory membership in them, is the object of ongoing political and legal debate. Both on the side of the courts and of the church, the present system has come under scrutiny, while the corporation representatives and also a majority of the population seem intent on maintaining it. This paper explains and examines the presently valid church-state relations, focusing on the Canton of Zurich, and looks at the suggestions for reform elaborated by an experts’ commission instituted by the Conference of Swiss Bishops. In conclusion, it presents some more general reflections on the challenges to individual and corporative religious freedom today, in Switzerland and beyond
From Frazier-Jawerth characterizations of Besov spaces to Wavelets and Decomposition spaces
This article describes how the ideas promoted by the fundamental papers
published by M. Frazier and B. Jawerth in the eighties have influenced
subsequent developments related to the theory of atomic decompositions and
Banach frames for function spaces such as the modulation spaces and
Besov-Triebel-Lizorkin spaces.
Both of these classes of spaces arise as special cases of two different,
general constructions of function spaces: coorbit spaces and decomposition
spaces. Coorbit spaces are defined by imposing certain decay conditions on the
so-called voice transform of the function/distribution under consideration. As
a concrete example, one might think of the wavelet transform, leading to the
theory of Besov-Triebel-Lizorkin spaces.
Decomposition spaces, on the other hand, are defined using certain
decompositions in the Fourier domain. For Besov-Triebel-Lizorkin spaces, one
uses a dyadic decomposition, while a uniform decomposition yields modulation
spaces.
Only recently, the second author has established a fruitful connection
between modern variants of wavelet theory with respect to general dilation
groups (which can be treated in the context of coorbit theory) and a particular
family of decomposition spaces. In this way, optimal inclusion results and
invariance properties for a variety of smoothness spaces can be established. We
will present an outline of these connections and comment on the basic results
arising in this context
The inner kernel theorem for a certain Segal algebra
The Segal algebra is well defined for arbitrary locally
compact Abelian Hausdorff (LCA) groups . Despite the fact that it is a
Banach space it is possible to derive a kernel theorem similar to the Schwartz
kernel theorem, of course without making use of the Schwartz kernel theorem.
First we characterize the bounded linear operators from
to by distributions in . We call this the "outer kernel theorem". The "inner kernel theorem" is
concerned with the characterization of those linear operators which have
kernels in the subspace , the main subject of
this manuscript. We provide a description of such operators as regularizing
operators in our context, mapping into test functions
in , in a -to norm continuous manner. The
presentation provides a detailed functional analytic treatment of the situation
and applies to the case of general LCA groups, without recurrence to the use of
so-called Wilson bases, which have been used for the case of elementary LCA
groups. The approach is then used in order to describe natural laws of
composition which imitate the composition of linear mappings via matrix
multiplications, now in a continuous setting. We use here that in a suitable
(weak) form these operators approximate general operators. We also provide an
explanation and mathematical justification used by engineers explaining in
which sense pure frequencies "integrate" to a Dirac delta distribution
Compactness Criteria in Function Spaces
The classical criterion for compactness in Banach spaces of functions can be
reformulated into a simple tightness condition in the time-frequency domain.
This description preserves more explicitly the symmetry between time and
frequency than the classical conditions. The result is first stated and proved
for L^2(R^d), and then generalized to coorbit spaces. As special cases, we
obtain new characterizations of compactness in Besov-Triebel-Lizorkin spaces,
modulation spaces and Bargmann-Fock spaces
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