50 research outputs found
The effective action and quantum gauge transformations
The local symmetry transformations of the quantum effective action for
general gauge theory are found. Additional symmetries arise under consideration
of background gauges. Together with "trivial" gauge transformations, vanishing
on mass shell, they can be used for construction simple gauge generators. For
example, for the Yang-Mills theory the classically invariant effective action
is obtained, reproducing DeWitt's result. For rank one theories a natural
generalization is proposed.Comment: Revtex, 11 pages; added reference
Symmetries and dynamics in constrained systems
We review in detail the Hamiltonian dynamics for constrained systems.
Emphasis is put on the total Hamiltonian system rather than on the extended
Hamiltonian system. We provide a systematic analysis of (global and local)
symmetries in total Hamiltonian systems. In particular, in analogue to total
Hamiltonians, we introduce the notion of total Noether charges. Grassmannian
degrees of freedom are also addressed in details.Comment: 1+97 pages, No figure, Expanded version of a lecture note by J.-H.
Park at Sogang University, Seoul during 2007-2008. Accepted for publication
in the European Physical Journal C as a review article; Reference adde
Parent formulation at the Lagrangian level
The recently proposed first-order parent formalism at the level of equations
of motion is specialized to the case of Lagrangian systems. It is shown that
for diffeomorphism-invariant theories the parent formulation takes the form of
an AKSZ-type sigma model. The proposed formulation can be also seen as a
Lagrangian version of the BV-BRST extension of the Vasiliev unfolded approach.
We also discuss its possible interpretation as a multidimensional
generalization of the Hamiltonian BFV--BRST formalism. The general construction
is illustrated by examples of (parametrized) mechanics, relativistic particle,
Yang--Mills theory, and gravity.Comment: 26 pages, discussion of the truncation extended, typos corrected,
references adde
First order parent formulation for generic gauge field theories
We show how a generic gauge field theory described by a BRST differential can
systematically be reformulated as a first order parent system whose spacetime
part is determined by the de Rham differential. In the spirit of Vasiliev's
unfolded approach, this is done by extending the original space of fields so as
to include their derivatives as new independent fields together with associated
form fields. Through the inclusion of the antifield dependent part of the BRST
differential, the parent formulation can be used both for on and off-shell
formulations. For diffeomorphism invariant models, the parent formulation can
be reformulated as an AKSZ-type sigma model. Several examples, such as the
relativistic particle, parametrized theories, Yang-Mills theory, general
relativity and the two dimensional sigma model are worked out in details.Comment: 36 pages, additional sections and minor correction
Covariant Quantization of the Brink-Schwarz Superparticle
The quantization of the Brink-Schwarz-Casalbuoni superparticle is performed
in an explicitly covariant way using the antibracket formalism. Since an
infinite number of ghost fields are required, within a suitable off-shell
twistor-like formalism, we are able to fix the gauge of each ghost sector
without modifying the physical content of the theory. The computation reveals
that the antibracket cohomology contains only the physical degrees of freedom.Comment: 24 page
A SUCCESSFUL COLLABORATION BETWEEN ADULT AND PEDIATRIC INTENSIVISTS: VENO-VENOUS EXTRACORPOREAL MEMBRANE OXYGENATION FOR A PEDIATRIC PATIENT WITH LIFE-THREATENING TRACHEAL OBSTRUCTION
peer reviewe
Differential impact of drugs on the outcome of ETV6-RUNX1 positive childhood B-cell precursor acute lymphoblastic leukaemia : results of the EORTC CLG 58881 and 58951 trials
info:eu-repo/semantics/publishe
Extensions of Mitral Valve Repair Techniques: Surgery for Endocarditis and Valvular Tumors
peer reviewedMitral valve repair has demonstrated its superiority over valve replacement. Mitral valve repair constitutes the optimal therapeutic option in case of degenerative dystrophic, rheumatic, congenital or ischemic mitral valve disease. These surgical techniques can also be successfully and advantageously applied in case of bacterial endocarditis or tumoral valvular disease. We report a case of staphylococcal endocarditis and another case of posterior leaflet fibroelastoma to show the place of conservative mitral surgery in these unusual indications
Translocation (16;17)(Q22;P13) Is a Recurrent Anomaly of Aneurysmal Bone Cysts
Recently, Panoutsakopoulos et al. (1999) reported 2 cases of aneurysmal bone cysts with a recurrent (16;17)(q22;p13) translocation. We present here two additional cases harboring the same translocation as well as additional chromosomal changes