2,214 research outputs found
SL(2,R) Chern-Simons Theories with Rational Charges and Two-dimensional Conformal Field Theories
This paper (completed March 1992) is an extensively revised and expanded
version of work which appeared July 1991 on the initial incarnation of the
hepth bulletin board, and which was published in the Proceedings of the
Workshop on String Theory, Trieste, March 1991. Abstract We present a
hamiltonian quantization of the 3-dimensional Chern-Simons theory
with fractional coupling constant on a space manifold with torus
topology in the ``constrain-first'' framework. By generalizing the ``Weyl-odd''
projection to the fractional charge case, we obtain multi-components
holomorphic wave functions whose components are the Kac-Wakimoto characters of
the modular invariant admissible representations of current
algebra with fractional level. The modular representations carried by the
quantum Hilbert space satisfy both Verlinde's and Vafa's constraints coming
from conformal field theory. They are the ``square-roots'' of the
representations associated to the conformal minimal models. Our results
imply that Chern-Simons theory with as gauge group, which describes
-dimensional gravity with negative cosmological constant, has the modular
properties of the Virasoro discrete series. On the way, we show that the
2-dimensional counterparts of Chern-Simons theories with half-integer
charge Comment: 29 pages, GEF-TH-92-
Weak Coupling Expansion of Yang-Mills Theory on Recursive Infinite Genus Surfaces
We analyze the partition function of two dimensional Yang-Mills theory on a
family of surfaces of infinite genus. These surfaces have a recursive
structure, which was used by one of us to compute the partition function that
results in a generalized Migdal formula. In this paper we study the `small
area' (weak coupling) expansion of the partition function, by exploiting the
fact that the generalized Migdal formula is analytic in the (complexification
of the) Euler characteristic. The structure of the perturbative part of the
weak coupling expansion suggests that the moduli space of flat connections (of
the SU(2) and SO(3) theories) on these infinite genus surfaces are well
defined, perhaps in an appropriate regularization.Comment: 1+18 pages, 2 figure
A Functional and Lagrangian Formulation of Two-Dimensional Topological Gravity
We reconsider two-dimensional topological gravity in a functional and
lagrangian framework. We derive its Slavnov-Taylor identities and discuss its
(in)dependence on the background gauge. Correlators of reparamerization
invariant observables are shown to be globally defined forms on moduli space.
The potential obstruction to their gauge-independence is the non-triviality of
the line bundle on moduli space , whose first Chern-class is
associated to the topological invariants of Mumford, Morita and Miller. Based
on talks given at the Fubini Fest, Torino, 24-26 February 1994, and at the
Workshop on String Theory, Trieste, 20-22 April 1994.Comment: 11 pages, harvmac, CERN-TH-7302/94, GEF-Th-6/199
New Supersymmetric Localizations from Topological Gravity
Supersymmetric field theories can be studied exactly on suitable off-shell
supergravity backgrounds. We show that in two dimensions such backgrounds are
identifiable with BRST invariant backgrounds of topological gravity coupled to
an abelian topological gauge multiplet. This latter background is required for
the consistent coupling of the topological `matter' YM theory to topological
gravity. We make use of this topological point of view to obtain, in a simple
and straightforward way, a complete classification of localizing supersymmetric
backgrounds in two dimensions. The BRST invariant topological backgrounds are
parametrized by both Killing vectors and -equivariant cohomology of the
2-dimensional world-sheet. We reconstruct completely the supergravity
backgrounds from the topological data: some of the supergravity fields are
twisted versions of the topological backgrounds, but others are "composite",
i.e. they are non-linear functionals of them. We recover all the known
localizing 2-dimensional backgrounds and (infinitely) many more that have not
been explored so far. We show that the supersymmetric -deformation is
nothing but the background value of the ghost-for-ghost of topological gravity,
a result which holds for other dimensions too. The new localizing backgrounds
are characterized by non-trivial fluxes for both the graviphotons of the
supergravity multiplet.Comment: 45 pages, 2 figures, revised introduction, version published on JHE
Mesothelioma and thymic tumors: Treatment challenges in (outside) a network setting
The management of patients with mesothelioma and thymic malignancy requires continuous multidisciplinary expertise at any step of the disease. A dramatic improvement in our knowledge has occurred in the last few years, through the development of databases, translational research programs, and clinical trials. Access to innovative strategies represents a major challenge, as there is a lack of funding for clinical research in rare cancers and their rarity precludes the design of robust clinical trials that could lead to specific approval of drugs. In this context, patient-centered initiatives, such as the establishment of dedicated networks, are warranted. International societies, such as IMIG (International Mesothelioma Interest Group) and ITMIG (International Thymic Malignancy Interest Group) provide infrastructure for global collaboration, and there are many advantages to having strong regional groups working on the same issues. There may be regional differences in risk factors, susceptibility, management and outcomes. The ability to address questions both regionally as well as globally is ideal to develop a full understanding of mesothelioma and thymic malignancies. In Europe, through the integration of national networks with EURACAN, the collaboration with academic societies and international groups, the development of networks in thoracic oncology provides multiplex integration of clinical care and research, ultimately ensuring equal access to high quality care to all patients, with the opportunity of conducting high level clinical and translational research projects
Chiral QED in Terms of Chiral Boson with a Generalized Fadeevian Regularization
Chiral QED with a generalized Fadeevian regularization is considered.
Imposing a chiral constraint a gauged version of Floranini-Jackiw lagrangian is
constructed. The imposition of the chiral constarint has spoiled t he
manifestly Lorentz covariance of the theory. The phase space structure for this
theory has been det ermined. It is found that spectrum changes drastically but
it is Lorentz invariant. Chiral fermion di sappears from the spectra and the
photon anquire mass as well. Poincare algebra has been calculated to show
physicial Lorentz invariance explicitely.Comment: 11 page
Investigational treatments for neurodegenerative diseases caused by inheritance of gene mutations: lessons from recent clinical trials
: We reviewed recent major clinical trials with investigational drugs for the treatment of subjects with neurodegenerative diseases caused by inheritance of gene mutations or associated with genetic risk factors. Specifically, we discussed randomized clinical trials in subjects with Alzheimer's disease, Huntington's disease and amyotrophic lateral sclerosis bearing pathogenic gene mutations, and glucocerebrosidase-associated Parkinson's disease. Learning potential lessons to improve future therapeutic approaches is the aim of this review. Two long-term, controlled trials on three anti-β-amyloid monoclonal antibodies (solanezumab, gantenerumab and crenezumab) in subjects carrying Alzheimer's disease-linked mutated genes encoding for amyloid precursor protein or presenilin 1 or presenilin 2 failed to show cognitive or functional benefits. A major trial on tominersen, an antisense oligonucleotide designed to reduce the production of the huntingtin protein in subjects with Huntington's disease, was prematurely interrupted because the drug failed to show higher efficacy than placebo and, at highest doses, led to worsened outcomes. A 28-week trial of tofersen, an antisense oligonucleotide for superoxide dismutase 1 in patients with amyotrophic lateral sclerosis with superoxide dismutase 1 gene mutations failed to show significant beneficial effects but the 1-year open label extension of this study indicated better clinical and functional outcomes in the group with early tofersen therapy. A trial of venglustat, a potent and brain-penetrant glucosylceramide synthase inhibitor, in Parkinson's disease subjects with heterozygous glucocerebrosidase gene mutations revealed worsened clinical and cognitive performance of patients on the enzyme inhibitor compared to placebo. We concluded that clinical trials in neurodegenerative diseases with a genetic basis should test monoclonal antibodies, antisense oligonucleotides or gene editing directed against the mutated enzyme or the mutated substrate without dramatically affecting physiological wild-type variants
The Kontsevich Connection on the Moduli Space of FZZT Liouville Branes
We point out that insertions of matrix fields in (connected amputated)
amplitudes of (generalized) Kontsevich models are given by covariant
derivatives with respect to the Kontsevich moduli. This implies that
correlators are sections of symmetric products of the (holomorphic) tangent
bundle on the (complexified) moduli space of FZZT Liouville branes. We discuss
the relation of Kontsevich parametrization of moduli space with that provided
by either the (p,1) or the (1,p) boundary conformal field theories. It turns
out that the Kontsevich connection captures the contribution of contact terms
to open string amplitudes of boundary cosmological constant operators in the
(1,p) minimal string models. The curvature of the connection is of type (1,1)
and has delta-function singularities at the points in moduli space where
Kontsevich kinetic term vanishes. We also outline the extention of our
formalism to the c=1 string at self-dual radius and discuss the problems that
have to be understood to reconciliate first and second quantized approaches in
this case.Comment: 34 pages, 2 eps figures, LaTex; typos corrected (including title);
more typos fixed, including those in Eqs.(72) and (132
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