BFFT quantization with nonlinear constraints

We consider the method due to Batalin, Fradkin, Fradkina, and Tyutin (BFFT) that makes the conversion of second-class constraints into first-class ones for the case of nonlinear theories. We first present a general analysis of an attempt to simplify the method, showing the conditions that must be fulfilled in order to have first-class constraints for nonlinear theories but that are linear in the auxiliary variables. There are cases where this simplification cannot be done and the full BFFT method has to be used. However, in the way the method is formulated, we show with details that it is not practicable to be done. Finally, we speculate on a solution for these problems.Comment: 19 pages, Late

Hamiltonian embedding of the massive noncommutative U(1) theory

We show that the massive noncommutative U(1) can be embedded in a gauge theory by using the BFFT Hamiltonian formalism. By virtue of the peculiar non-Abelian algebraic structure of the noncommutative massive U(1) theory, several specific identities involving Moyal commutators had to be used in order to make the embedding possible. This leads to an infinite number of steps in the iterative process of obtaining first-class constraints. We also shown that the involutive Hamiltonian can be constructed.Comment: 8 pages, Revtex (multicol

Quantum complex scalar fields and noncommutativity

In this work we analyze complex scalar fields using a new framework where the object of noncommutativity $\theta^{\mu\nu}$ represents independent degrees of freedom. In a first quantized formalism, $\theta^{\mu\nu}$ and its canonical momentum $\pi_{\mu\nu}$ are seen as operators living in some Hilbert space. This structure is compatible with the minimal canonical extension of the Doplicher-Fredenhagen-Roberts (DFR) algebra and is invariant under an extended Poincar\'e group of symmetry. In a second quantized formalism perspective, we present an explicit form for the extended Poincar\'e generators and the same algebra is generated via generalized Heisenberg relations. We also introduce a source term and construct the general solution for the complex scalar fields using the Green's function technique.Comment: 13 pages. Latex. Final version to appear in Physical Review

The Hamiltonian BRST quantization of a noncommutative nonabelian gauge theory and its Seiberg-Witten map

We consider the Hamiltonian BRST quantization of a noncommutative non abelian gauge theory. The Seiberg-Witten map of all phase-space variables, including multipliers, ghosts and their momenta, is given in first order in the noncommutative parameter $\theta$. We show that there exists a complete consistence between the gauge structures of the original and of the mapped theories, derived in a canonical way, once we appropriately choose the map solutions.Comment: 10 pages, Latex. Address adde

Noncommutative Particles in Curved Spaces

We present a formulation in a curved background of noncommutative mechanics, where the object of noncommutativity $\theta^{\mu\nu}$ is considered as an independent quantity having a canonical conjugate momentum. We introduced a noncommutative first-order action in D=10 curved spacetime and the covariant equations of motions were computed. This model, invariant under diffeomorphism, generalizes recent relativistic results.Comment: 1+15 pages. Latex. New comments and results adde

A Novel Variant of DeSanto-Shinawi Syndrome with Joint Manifestations

variable degrees of developmental delay and intellectual disability that were recently delineated as DeSanto- Shinawi syndrome (OMIM 616708). We describe a patient with DeSanto-Shinawi syndrome caused by a novel frameshift variant in WAC gene (NM_016628.4(WAC):c.1689del (p.Phe563Leufs*6)). As noted in cases previously reported, our patient phenotype included facial dysmorphism, intellectual disability, behavioral problems, feeding difficulties, hirsutism, constipation and astigmatism. She also had limited range of motion of joints since birth and Juvenile Idiopathic Arthritis diagnosed at eleven years old. Although in the last years some additional features were reported in DeSanto-Shinawi syndrome, joint manifestations have not been previously described. As limited range of motion of joints was reported since birth with no correlation with arthritis onset, it could be a new clinical feature. Polyarthritis in this patient can be only a coincidence, since there is a first degree relative with psoriasis, or might be related to WAC mutation. Indeed, WAC encodes a protein that plays a vital role in autophagy. It has already been demonstrated that WAC haploinsufficiency leads to increased autophagy and, according to different authors, increased autophagy may display a pathogenic role in several autoimmune disorders such as Rheumatoid Arthritis and Juvenile Idiopathic Arthritis. Thus, WAC haploinsufficiency may have contributed to autoimmune disorder in this patient.info:eu-repo/semantics/publishedVersio

Axial Anomaly from the BPHZ regularized BV master equation

A BPHZ renormalized form for the master equation of the field antifiled (or BV) quantization has recently been proposed by De Jonghe, Paris and Troost. This framework was shown to be very powerful in calculating gauge anomalies. We show here that this equation can also be applied in order to calculate a global anomaly (anomalous divergence of a classically conserved Noether current), considering the case of QED. This way, the fundamental result about the anomalous contribution to the Axial Ward identity in standard QED (where there is no gauge anomaly) is reproduced in this BPHZ regularized BV framework.Comment: 10 pages, Latex, minor changes in the reference

HERA-B Framework for Online Calibration and Alignment

This paper describes the architecture and implementation of the HERA-B framework for online calibration and alignment. At HERA-B the performance of all trigger levels, including the online reconstruction, strongly depends on using the appropriate calibration and alignment constants, which might change during data taking. A system to monitor, recompute and distribute those constants to online processes has been integrated in the data acquisition and trigger systems.Comment: Submitted to NIM A. 4 figures, 15 page

Clustering stability and ground truth: numerical experiments

Stability has been considered an important property for evaluating clustering solutions. Nevertheless, there are no conclusive studies on the relationship between this property and the capacity to recover clusters inherent to data (“ground truth”). This study focuses on this relationship, resorting to experiments on synthetic data generated under diverse scenarios (controlling relevant factors) and experiments on real data sets. Stability is evaluated using a weighted cross-validation procedure. Indices of agreement (corrected for agreement by chance) are used both to assess stability and external validity. The results obtained reveal a new perspective so far not mentioned in the literature. Despite the clear relationship between stability and external validity when a broad range of scenarios is considered, the within-scenarios conclusions deserve our special attention: faced with a specific clustering problem (as we do in practice), there is no significant relationship between clustering stability and the ability to recover data clustersinfo:eu-repo/semantics/publishedVersio

Tensor Coordinates in Noncommutative Mechanics

A consistent classical mechanics formulation is presented in such a way that, under quantization, it gives a noncommutative quantum theory with interesting new features. The Dirac formalism for constrained Hamiltonian systems is strongly used, and the object of noncommutativity ${\mathbf \theta}^{ij}$ plays a fundamental rule as an independent quantity. The presented classical theory, as its quantum counterpart, is naturally invariant under the rotation group $SO(D)$.Comment: 12 pages, Late