5,231 research outputs found
Wedge Local Deformations of Charged Fields leading to Anyonic Commutation Relations
The method of deforming free fields by using multiplication operators on Fock
space, introduced by G. Lechner in [11], is generalized to a charged free field
on two- and three-dimensional Minkowski space. In this case the deformation
function can be chosen in such a way that the deformed fields satisfy
generalized commutation relations, i.e. they behave like Anyons instead of
Bosons. The fields are "polarization free" in the sense that they create only
one-particle states from the vacuum and they are localized in wedges (or "paths
of wedges"), which makes it possible to circumvent a No-Go theorem by J. Mund
[12], stating that there are no free Anyons localized in spacelike cones. The
two-particle scattering matrix, however, can be defined and is different from
unity
On the equivalence of two deformation schemes in quantum field theory
Two recent deformation schemes for quantum field theories on the
two-dimensional Minkowski space, making use of deformed field operators and
Longo-Witten endomorphisms, respectively, are shown to be equivalent.Comment: 14 pages, no figure. The final version is available under Open
Access. CC-B
An operator expansion for integrable quantum field theories
A large class of quantum field theories on 1+1 dimensional Minkowski space,
namely, certain integrable models, has recently been constructed rigorously by
Lechner. However, the construction is very abstract and the concrete form of
local observables in these models remains largely unknown. Aiming for more
insight into their structure, we establish a series expansion for observables,
similar but not identical to the well-known form factor expansion. This
expansion will be the basis for a characterization and explicit construction of
local observables, to be discussed elsewhere. Here, we establish the expansion
independent of the localization aspect, and analyze its behavior under
space-time symmetries. We also clarify relations with deformation methods in
quantum field theory, specifically, with the warped convolution in the sense of
Buchholz and Summers.Comment: minor corrections and clarifications, as published in J. Phys A; 24
page
Warped Convolutions, Rieffel Deformations and the Construction of Quantum Field Theories
Warped convolutions of operators were recently introduced in the algebraic
framework of quantum physics as a new constructive tool. It is shown here that
these convolutions provide isometric representations of Rieffel's strict
deformations of C*-dynamical systems with automorphic actions of R^n, whenever
the latter are presented in a covariant representation. Moreover, the device
can be used for the deformation of relativistic quantum field theories by
adjusting the convolutions to the geometry of Minkowski space. The resulting
deformed theories still comply with pertinent physical principles and their
Tomita-Takesaki modular data coincide with those of the undeformed theory; but
they are in general inequivalent to the undeformed theory and exhibit different
physical interpretations.Comment: 34 page
Deformations of Fermionic Quantum Field Theories and Integrable Models
Considering the model of a scalar massive Fermion, it is shown that by means
of deformation techniques it is possible to obtain all integrable quantum field
theoretic models on two-dimensional Minkowski space which have factorizing
S-matrices corresponding to two-particle scattering functions S_2 satisfying
S_2(0) = -1. Among these models there is for example the Sinh-Gordon model. Our
analysis provides a complement to recent developments regarding deformations of
quantum field theories. The deformed model is investigated also in higher
dimensions. In particular, locality and covariance properties are analyzed.Comment: 20 page
IWB: Beiträge zur Wirtschaftspolitik
Die "Beiträge" sind ein Forum zur Diskussion aktueller wirtschaftspolitischer Problemfelder im In- und Ausland. Sie sollen Aspekte der Wirtschaftspolitik beleuchten, die von der Praxis und ihren akademischen Beratern vernachlässigt werden und anfechtbaren Positionen aus Praxis und Wissenschaft begründet entgegentreten
Immunoreactive inhibin in human follicular fluid in an ovarian hyperstimulation proramme for in vitro fertilisation: correlations and different forms
Construction of wedge-local nets of observables through Longo-Witten endomorphisms. II
In the first part, we have constructed several families of interacting
wedge-local nets of von Neumann algebras. In particular, there has been
discovered a family of models based on the endomorphisms of the U(1)-current
algebra of Longo-Witten.
In this second part, we further investigate endomorphisms and interacting
models. The key ingredient is the free massless fermionic net, which contains
the U(1)-current net as the fixed point subnet with respect to the U(1) gauge
action. Through the restriction to the subnet, we construct a new family of
Longo-Witten endomorphisms on the U(1)-current net and accordingly interacting
wedge-local nets in two-dimensional spacetime. The U(1)-current net admits the
structure of particle numbers and the S-matrices of the models constructed here
do mix the spaces with different particle numbers of the bosonic Fock space.Comment: 33 pages, 1 tikz figure. The final version is available under Open
Access. CC-B
Staging Hitler myths
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Title from PDF of title page (University of Missouri--Columbia, viewed on November 18, 2009).Thesis advisor: Dr. Roger Cook.M.A. University of Missouri--Columbia 2009.In my thesis Staging Hitler Myths, I analyze the depiction of Adolf Hitler in the contemporary German movies Der Untergang (2004) and Mein Fuhrer-die wirkliche wahrste Wahrheit uber Adolf Hitler (2007). Both movies have been harshly criticized for offering a personalized depiction of the historical character of Adolf Hitler. A crucial question that came up in the reviews was whether the depiction of Hitler in these films has been "adequate". To me all these depictions circle around the mythology that has been developed around Hitler. Referring to the concept of the French linguist Roland Barthes I would like to expose the correlation of the image, the history and the representation of both for the myth. The depiction of Hitler is never simply a depiction of a historical figure. It includes the interlude between the staging of Hitler himself and the representation of history. This opens up space for interpretation. This interpretation is unable to display any historical accuracy based on fact. Since filmmaking is a selective process it can only provide us with an interpretation of these facts. It tells us more about the purpose of the filmmaker than it does about Hitler.Includes bibliographical references
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