105 research outputs found
Reflexive representability and stable metrics
It is well-known that a topological group can be represented as a group of
isometries of a reflexive Banach space if and only if its topology is induced
by weakly almost periodic functions (see
\cite{Shtern:CompactSemitopologicalSemigroups},
\cite{Megrelishvili:OperatorTopologies} and
\cite{Megrelishvili:TopologicalTransformations}). We show that for a metrisable
group this is equivalent to the property that its metric is uniformly
equivalent to a stable metric in the sense of Krivine and Maurey (see
\cite{Krivine-Maurey:EspacesDeBanachStables}). This result is used to give a
partial negative answer to a problem of Megrelishvili
Generalized Bloch analysis and propagators on Riemannian manifolds with a discrete symmetry
We consider an invariant quantum Hamiltonian in the
space based on a Riemannian manifold with a countable
discrete symmetry group . Typically, is the universal
covering space of a multiply connected Riemannian manifold and is
the fundamental group of . On the one hand, following the basic step of the
Bloch analysis, one decomposes the space over into a direct
integral of Hilbert spaces formed by equivariant functions on . The
Hamiltonian decomposes correspondingly, with each component
being defined by a quasi-periodic boundary condition. The quasi-periodic
boundary conditions are in turn determined by irreducible unitary
representations of . On the other hand, fixing a
quasi-periodic boundary condition (i.e., a unitary representation of
) one can express the corresponding propagator in terms of the
propagator associated to the Hamiltonian . We discuss these procedures in
detail and show that in a sense they are mutually inverse
SOME ABSTRACT PROPERTIES OF SEMIGROUPS APPEARING IN SUPERCONFORMAL THEORIES
A new type of semigroups which appears while dealing with
superconformal symmetry in superstring theories is considered. The ideal series
having unusual abstract properties is constructed. Various idealisers are
introduced and studied. The ideal quasicharacter is defined. Green's relations
are found and their connection with the ideal quasicharacter is established.Comment: 11 page
Towards Urban Geopolitics of Encounter: Spatial Mixing in Contested Jerusalem
The extent to which 'geographies of encounter' facilitate tolerance of diversity and difference has long been a source of debate in urban studies and human geography scholarship. However, to date this contestation has focused primarily on hyper-diverse cities in the global north-west. Adapting this debate to the volatile conditions of the nationally-contested city, this paper explores intergroup encounters between Israelis and Palestinians in Jerusalem. The paper suggests that in the context of hyper-polarisation of the nationally-contested urban space, the study of encounter should focus on macro-scale structural forces. In Jerusalem, we stress the role of ethnonationality and neoliberalism as key producers of its asymmetric and volatile yet highly resilient geography of intergroup encounters. In broader sense, as many cities worldwide experience a resurgence of ethnonationalism, illuminating the structural production of encounter may demarcate a broader function for reading contemporary urban geopolitics
Recommended from our members
Report of the Joint Working Group on Telemammography/Teleradiology and Information Management
- …