503 research outputs found
Transgender Genealogy in Tristan de Nanteuil
This article proposes the use of transgender theory within medieval studies as both a productive and a politically significant optic. The article employs transgender theory to effect a new reading of the miraculous transformation of the character of Blanchandin/e, in the fourteenth-century French chanson de geste, Tristan de Nanteuil, from female to male. First, the often-overlooked importance of Judith Butler’s analysis of sex and gender for the understanding of transgender and non-normatively-gendered identities is addressed. Next, using theoretical work by Deleuze, and by Deleuze and Guattari, the article demonstrates how the rhizomatic and folding structures that a transgender reading of Blanchandin/e’s transformation brings to light cohere with the series of rhizomes and folds which structure the genealogical logic of the text as a whole. The family tree of Tristan de Nanteuil is shown to answer to queer, rhizomatic, and folding imperatives. In this way, the article demonstrates that the text’s transgender genealogy contradicts the anti-generative model of queerness proposed by queer theory’s antisocial turn
Coarse distance from dynamically convex to convex
Chaidez and Edtmair have recently found the first example of dynamically
convex domains in that are not symplectomorphic to convex domains
(called symplectically convex domains), answering a long-standing open
question. In this paper, we discover new examples of such domains without
referring to Chaidez-Edtmair's criterion. We also show that these domains are
arbitrarily far from the set of symplectically convex domains in
with respect to the coarse symplectic Banach-Mazur distance by using an
explicit numerical criterion for symplectic non-convexity.Comment: 18 pages, 7 figure
Methyl group dynamics in a confined glass
We present a neutron scattering investigation on methyl group dynamics in
glassy toluene confined in mesoporous silicates of different pore sizes. The
experimental results have been analysed in terms of a barrier distribution
model, such a distribution following from the structural disorder in the glassy
state. Confinement results in a strong decreasing of the average rotational
barrier in comparison to the bulk state. We have roughly separated the
distribution for the confined state in a bulk-like and a surface-like
contribution, corresponding to rotors at a distance from the pore wall
respectively larger and smaller than the spatial range of the interactions
which contribute to the rotational potential for the methyl groups. We have
estimated a distance of 7 Amstrong as a lower limit of the interaction range,
beyond the typical nearest-neighbour distance between centers-of-mass (4.7
Amstrong).Comment: 5 pages, 3 figures. To be published in European Physical Journal E
Direct. Proceedings of the 2nd International Workshop on Dynamics in
Confinemen
Classification of Invariant Star Products up to Equivariant Morita Equivalence on Symplectic Manifolds
In this paper we investigate equivariant Morita theory for algebras with
momentum maps and compute the equivariant Picard groupoid in terms of the
Picard groupoid explicitly. We consider three types of Morita theory:
ring-theoretic equivalence, *-equivalence and strong equivalence. Then we apply
these general considerations to star product algebras over symplectic manifolds
with a Lie algebra symmetry. We obtain the full classification up to
equivariant Morita equivalence.Comment: 28 pages. Minor update, fixed typos
Traces for star products on the dual of a Lie algebra
In this paper, we describe all traces for the BCH star-product on the dual of
a Lie algebra. First we show by an elementary argument that the BCH as well as
the Kontsevich star-product are strongly closed if and only if the Lie algebra
is unimodular. In a next step we show that the traces of the BCH star-product
are given by the \ad-invariant functionals. Particular examples are the
integration over coadjoint orbits. We show that for a compact Lie group and a
regular orbit one can even achieve that this integration becomes a positive
trace functional. In this case we explicitly describe the corresponding GNS
representation. Finally we discuss how invariant deformations on a group can be
used to induce deformations of spaces where the group acts on.Comment: 18 pages, LaTeX2e. Updated reference
Closedness of star products and cohomologies
We first review the introduction of star products in connection with
deformations of Poisson brackets and the various cohomologies that are related
to them. Then we concentrate on what we have called ``closed star products" and
their relations with cyclic cohomology and index theorems. Finally we shall
explain how quantum groups, especially in their recent topological form, are in
essence examples of star products.Comment: 16 page
On Gammelgaard's formula for a star product with separation of variables
We show that Gammelgaard's formula expressing a star product with separation
of variables on a pseudo-Kaehler manifold in terms of directed graphs without
cycles is equivalent to an inversion formula for an operator on a formal Fock
space. We prove this inversion formula directly and thus offer an alternative
approach to Gammelgaard's formula which gives more insight into the question
why the directed graphs in his formula have no cycles.Comment: 29 pages, changes made in the last two section
Infinitesimal deformations of a formal symplectic groupoid
Given a formal symplectic groupoid over a Poisson manifold ,
we define a new object, an infinitesimal deformation of , which can be
thought of as a formal symplectic groupoid over the manifold equipped with
an infinitesimal deformation of the Poisson bivector
field . The source and target mappings of a deformation of are
deformations of the source and target mappings of . To any pair of natural
star products having the same formal symplectic groupoid
we relate an infinitesimal deformation of . We call it the deformation
groupoid of the pair . We give explicit formulas for the
source and target mappings of the deformation groupoid of a pair of star
products with separation of variables on a Kaehler- Poisson manifold. Finally,
we give an algorithm for calculating the principal symbols of the components of
the logarithm of a formal Berezin transform of a star product with separation
of variables. This algorithm is based upon some deformation groupoid.Comment: 22 pages, the paper is reworked, new proofs are adde
The Stability of Bredigite and Other Ca-Mg Silicates
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65844/1/j.1151-2916.1980.tb10213.x.pd
Phase Space Reduction for Star-Products: An Explicit Construction for CP^n
We derive a closed formula for a star-product on complex projective space and
on the domain using a completely elementary
construction: Starting from the standard star-product of Wick type on and performing a quantum analogue of Marsden-Weinstein
reduction, we can give an easy algebraic description of this star-product.
Moreover, going over to a modified star-product on ,
obtained by an equivalence transformation, this description can be even further
simplified, allowing the explicit computation of a closed formula for the
star-product on \CP^n which can easily transferred to the domain
.Comment: LaTeX, 17 page
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