1,108 research outputs found
The regularized BRST Jacobian of pure Yang-Mills theory
The Jacobian for infinitesimal BRST transformations of path integrals for
pure Yang-Mills theory, viewed as a matrix \unity +\Delta J in the space of
Yang-Mills fields and (anti)ghosts, contains off-diagonal terms. Naively, the
trace of vanishes, being proportional to the trace of the structure
constants. However, the consistent regulator \cR, constructed from a general
method, also contains off-diagonal terms. An explicit computation demonstrates
that the regularized Jacobian Tr\ \Delta J\exp -\cR /M^2 for is the variation of a local counterterm, which we give. This is a
direct proof at the level of path integrals that there is no BRST anomaly.Comment: 12 pages, latex, CERN-TH.6541/92, KUL-TF-92/2
Nonsense mutations in alpha-II spectrin in three families with juvenile onset hereditary motor neuropathy
Distal hereditary motor neuropathies are a rare subgroup of inherited peripheral neuropathies hallmarked by a length-dependent axonal degeneration of lower motor neurons without significant involvement of sensory neurons. We identified patients with heterozygous nonsense mutations in the alpha II-spectrin gene, SPTAN1, in three separate dominant hereditary motor neuropathy families via next-generation sequencing. Variable penetrance was noted for these mutations in two of three families, and phenotype severity differs greatly between patients. The mutant mRNA containing nonsense mutations is broken down by nonsense-mediated decay and leads to reduced protein levels in patient cells. Previously, dominant-negative alpha II-spectrin gene mutations were described as causal in a spectrum of epilepsy phenotypes
Multisystem proteinopathy due to a homozygous p.Arg159His VCP mutation : a tale of the unexpected
ObjectiveTo assess the clinical, radiologic, myopathologic, and proteomic findings in a patient manifesting a multisystem proteinopathy due to a homozygous valosin-containing protein gene (VCP) mutation previously reported to be pathogenic in the heterozygous state.MethodsWe studied a 36-year-old male index patient and his father, both presenting with progressive limb-girdle weakness. Muscle involvement was assessed by MRI and muscle biopsies. We performed whole-exome sequencing and Sanger sequencing for segregation analysis of the identified p.Arg159His VCP mutation. To dissect biological disease signatures, we applied state-of-the-art quantitative proteomics on muscle tissue of the index case, his father, 3 additional patients with VCP-related myopathy, and 3 control individuals.ResultsThe index patient, homozygous for the known p.Arg159His mutation in VCP, manifested a typical VCP-related myopathy phenotype, although with a markedly high creatine kinase value and a relatively early disease onset, and Paget disease of bone. The father exhibited a myopathy phenotype and discrete parkinsonism, and multiple deceased family members on the maternal side of the pedigree displayed a dementia, parkinsonism, or myopathy phenotype. Bioinformatic analysis of quantitative proteomic data revealed the degenerative nature of the disease, with evidence suggesting selective failure of muscle regeneration and stress granule dyshomeostasis.ConclusionWe report a patient showing a multisystem proteinopathy due to a homozygous VCP mutation. The patient manifests a severe phenotype, yet fundamental disease characteristics are preserved. Proteomic findings provide further insights into VCP-related pathomechanisms
Superspace formulation of general massive gauge theories and geometric interpretation of mass-dependent BRST symmetries
A superspace formulation is proposed for the osp(1,2)-covariant Lagrangian
quantization of general massive gauge theories. The superalgebra os0(1,2) is
considered as subalgebra of sl(1,2); the latter may be considered as the
algebra of generators of the conformal group in a superspace with two
anticommuting coordinates. The mass-dependent (anti)BRST symmetries of proper
solutions of the quantum master equations in the osp(1,2)-covariant formalism
are realized in that superspace as invariance under translations combined with
mass-dependent special conformal transformations. The Sp(2) symmetry - in
particular the ghost number conservation - and the "new ghost number"
conservation are realized as invariance under symplectic rotations and
dilatations, respectively. The transformations of the gauge fields - and of the
full set of necessarily required (anti)ghost and auxiliary fields - under the
superalgebra sl(1,2) are determined both for irreducible and first-stage
reducible theories with closed gauge algebra.Comment: 35 pages, AMSTEX, precision of reference
Simplifications in Lagrangian BV quantization exemplified by the anomalies of chiral gravity
The Batalin--Vilkovisky (BV) formalism is a useful framework to study gauge
theories. We summarize a simple procedure to find a a gauge--fixed action in
this language and a way to obtain one--loop anomalies. Calculations involving
the antifields can be greatly simplified by using a theorem on the antibracket
cohomology. The latter is based on properties of a `Koszul--Tate differential',
namely its acyclicity and nilpotency. We present a new proof for this
acyclicity, respecting locality and covariance of the theory. This theorem then
implies that consistent higher ghost terms in various expressions exist, and it
avoids tedious calculations.
This is illustrated in chiral gravity. We compute the one--loop anomaly
without terms of negative ghost number. Then the mentioned theorem and the
consistency condition imply that the full anomaly is determined up to local
counterterms. Finally we show how to implement background charges into the BV
language in order to cancel the anomaly with the appropriate counterterms.
Again we use the theorem to simplify the calculations, which agree with
previous results.Comment: 45 page
EXCEPTIONAL ACCUMULATIONS OF STATOLITHS IN ASSOCIATION WITH THE CHRISTIAN MALFORD LAGERSTA¨ TTE (CALLOVIAN, JURASSIC) IN WILTSHIRE, UNITED KINGDOM
Regularisation, the BV method, and the antibracket cohomology
We review the Lagrangian Batalin--Vilkovisky method for gauge theories. This
includes gauge fixing, quantisation and regularisation. We emphasize the role
of cohomology of the antibracket operation. Our main example is gravity,
for which we also discuss the solutions for the cohomology in the space of
local integrals. This leads to the most general form for the action, for
anomalies and for background charges.Comment: 12 pages, LaTeX, Preprint-KUL-TF-94/2
Integrable Schr\"odinger operators with magnetic fields: factorisation method on curved surfaces
The factorisation method for Schr\"odinger operators with magnetic fields on
a two-dimensional surface with non-trivial metric is investigated. This
leads to the new integrable examples of such operators and brings a new look at
some classical problems such as Dirac magnetic monopole and Landau problem. The
global geometric aspects and related spectral properties of the operators from
the factorisation chains are discussed in details. We also consider the Laplace
transformations on a curved surface and extend the class of Schr\"odinger
operators with two integrable levels introduced in the flat case by S.P.Novikov
and one of the authors.Comment: 20 page
Comments on the Covariant Sp(2)-Symmetric Lagrangian BRST Formalism
We give a simple geometrical picture of the basic structures of the covariant
symmetric quantization formalism -- triplectic quantization -- recently
suggested by Batalin, Marnelius and Semikhatov. In particular, we show that the
appearance of an even Poisson bracket is not a particular property of
triplectic quantization. Rather, any solution of the classical master equation
generates on a Lagrangian surface of the antibracket an even Poisson bracket.
Also other features of triplectic quantization can be identified with aspects
of conventional Lagrangian BRST quantization without extended BRST symmetry.Comment: 9 pages, LaTe
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