77 research outputs found
A Note on Representations of N=2 SW-Algebras
We investigate the representation theory of some recently constructed N=2
super W-algebras with two generators. Except for the central charges in the
unitary minimal series of the N=2 super Virasoro algebra we find no new
rational models. However, from our results it is possible to arrange all known
N=2 super W-algebras with two generators and vanishing self-coupling constant
into four classes. For the algebras existing for c >= 3 which can be understood
by the spectral flow of the N=2 super Virasoro algebra we find that the
representations have quantized U(1) charge.Comment: 11 pages + 7 figures (postscript); plain TeX, psfig.tex;
BONN-TH-94-0
Coset Realization of Unifying W-Algebras
We construct several quantum coset W-algebras, e.g. sl(2,R)/U(1) and
sl(2,R)+sl(2,R) / sl(2,R), and argue that they are finitely nonfreely
generated. Furthermore, we discuss in detail their role as unifying W-algebras
of Casimir W-algebras. We show that it is possible to give coset realizations
of various types of unifying W-algebras, e.g. the diagonal cosets based on the
symplectic Lie algebras sp(2n) realize the unifying W-algebras which have
previously been introduced as `WD_{-n}'. In addition, minimal models of WD_{-n}
are studied. The coset realizations provide a generalization of
level-rank-duality of dual coset pairs. As further examples of finitely
nonfreely generated quantum W-algebras we discuss orbifolding of W-algebras
which on the quantum level has different properties than in the classical case.
We demonstrate in some examples that the classical limit according to Bowcock
and Watts of these nonfreely finitely generated quantum W-algebras probably
yields infinitely nonfreely generated classical W-algebras.Comment: 60 pages (plain TeX) (final version to appear in Int. J. Mod. Phys.
A; several minor improvements and corrections - for details see beginning of
file
New N=1 Extended Superconformal Algebras with Two and Three Generators
In this paper we consider extensions of the super Virasoro algebra by one and
two super primary fields. Using a non-explicitly covariant approach we compute
all SW-algebras with one generator of dimension up to 7 in addition to the
super Virasoro field. In complete analogy to W-algebras with two generators
most results can be classified using the representation theory of the super
Virasoro algebra. Furthermore, we find that the SW(3/2, 11/2)-algebra can be
realized as a subalgebra of SW(3/2, 5/2) at c = 10/7. We also construct some
new SW-algebras with three generators, namely SW(3/2, 3/2, 5/2), SW(3/2, 2, 2)
and SW(3/2, 2, 5/2).Comment: 30 pages (Plain TeX), BONN-HE-92-0
On the electronic structure of electron doped LaOFeAs as seen by X-ray absorption spectroscopy
We investigated the recently found superconductor LaO_{1-x}F_xFeAs by X-ray
absorption spectroscopy (XAS). From a comparison of the O K-edge with LDA
calculations we find good agreement and are able to explain the structure and
changes of the spectra with electron doping. An important result from this edge
is a limitation of the Hubbard U to values not significantly larger than 1 eV.
From experimental Fe L_2,3-edge spectra and charge transfer multiplet
calculations we gain further information on important physical values such as
hopping parameters, the charge transfer energy Delta, and the on-site Hubbard
U. Furthermore we find the system to be very covalent with a large amount of
ligand holes. A shift in the chemical potential is visible in the O K- and Fe
L_2,3-edge spectra which emphasizes the importance of band effects in these
compounds.Comment: 4 pages, 2 figure
Translating genome-wide association findings into new therapeutics for psychiatry
Genome-wide association studies (GWAS) in psychiatry, once they reach sufficient sample size and power, have been enormously successful. The Psychiatric Genomics Consortium (PGC) aims for mega-analyses with sample sizes that will grow to (cumulatively) >1 million individuals in the next 5 years. This should lead to hundreds of new findings for common genetic variants across nine psychiatric disorders studied by the PGC. The new targets discovered by GWAS have the potential to restart largely stalled psychiatric drug development pipelines, and the translation of GWAS findings into the clinic is a key aim of the recently funded phase 3 of the PGC. This is not without considerable technical challenges. These approaches complement the other main aim of GWAS studies on risk prediction approaches for improving detection, differential diagnosis, and clinical trial design. This paper outlines the motivations, technical and analytical issues, and the plans for translating PGC3 findings into new therapeutics
Collective and noncollective states in (120)Te
High-spin states in (120)Te were populated in the reaction (80)Se((48)Ca, alpha 4n)(120)Te at a beam energy of 207 MeV and gamma-ray coincidences were measured using the Gammasphere spectrometer. The previously known level scheme is extended to higher spin and new interband transitions and side-feeding branches are established. Five highly deformed rotational bands, extending up to almost I = 50, are observed for the first time. The bands are compared with similar structures found recently in neighboring nuclei. The experimental results are interpreted within the framework of the cranked Nilsson-Strutinsky model. Configuration assignments to several terminating states and to the high-spin bands are discussed
Darstellungstheorie von W- und Super-W-Algebren
SIGLEAvailable from TIB Hannover: RN 4852(92-11) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
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