Hamiltonian vs Lagrangian Embedding of a Massive Spin-one Theory Involving 2-form Field

We consider the Hamiltonian and Lagrangian embedding of a first-order, massive spin-one, gauge non-invariant theory involving anti-symmetric tensor field. We apply the BFV-BRST generalised canonical approach to convert the model to a first class system and construct nil-potent BFV-BRST charge and an unitarising Hamiltonian. The canonical analysis of the St\"uckelberg formulation of this model is presented. We bring out the contrasting feature in the constraint structure, specifically with respect to the reducibility aspect, of the Hamiltonian and the Lagrangian embedded model. We show that to obtain manifestly covariant St\"uckelberg Lagrangian from the BFV embedded Hamiltonian, phase space has to be further enlarged and show how the reducible gauge structure emerges in the embedded model.Comment: Revtex, 13 pages, no figure, to appear in Int. J. Mod. Phys.

Orographic effect on tropical rain physics in the Asian monsoon region

Effect of orography on tropical rain drop size distribution (DSD), which was not well known, is evidenced through the present study. DSD is the number of raindrops/unit volume/diameter interval, which tells about the underlying physics of rainfall process. Rain DSD was studied, using a Joss-Waldvogel disdrometer, at three coastal and a hill station in the Tropics. The variation in the characteristics of three physically significant parameters derived from the DSD with rain rate clearly unraveled the effect of orography on rain physics. The orographic rain appears to have larger drops compared with nonorographic rains when rain rate is high

On the equivalence between topologically and non-topologically massive abelian gauge theories

We analyse the equivalence between topologically massive gauge theory (TMGT) and different formulations of non-topologically massive gauge theories (NTMGTs) in the canonical approach. The different NTMGTs studied are St\"uckelberg formulation of (A) a first order formulation involving one and two form fields, (B) Proca theory, and (C) massive Kalb-Ramond theory. We first quantise these reducible gauge systems by using the phase space extension procedure and using it, identify the phase space variables of NTMGTs which are equivalent to the canonical variables of TMGT and show that under this the Hamiltonian also get mapped. Interestingly it is found that the different NTMGTs are equivalent to different formulations of TMGTs which differ only by a total divergence term. We also provide covariant mappings between the fields in TMGT to NTMGTs at the level of correlation function.Comment: One reference added and a typos corrected. 15 pages, To appear in Mod. Phys. Lett.

State-recycling and time-resolved imaging in topological photonic lattices

Photonic lattices - arrays of optical waveguides - are powerful platforms for simulating a range of phenomena, including topological phases. While probing dynamics is possible in these systems, by reinterpreting the propagation direction as "time," accessing long timescales constitutes a severe experimental challenge. Here, we overcome this limitation by placing the photonic lattice in a cavity, which allows the optical state to evolve through the lattice multiple times. The accompanying detection method, which exploits a multi-pixel single-photon detector array, offers quasi-real time-resolved measurements after each round trip. We apply the state-recycling scheme to intriguing photonic lattices emulating Dirac fermions and Floquet topological phases. In this new platform, we also realise a synthetic pulsed electric field, which can be used to drive transport within photonic lattices. This work opens a new route towards the detection of long timescale effects in engineered photonic lattices and the realization of hybrid analogue-digital simulators.Comment: Comments are welcom

Duality of massive gauge invariant theories in arbitrary space-time dimension

We show that dualization of Stueckelberg-like massive gauge theories and $B\wedge F$ models, follows form a general p-dualization of interacting theories in d spacetime dimensions. This is achieved by a particular choice of the external current.Comment: ReVTeX 7pages, no figures, accepted for publ. in Phys.Rev.

PERFORMANCE ANALYSIS USING CODE CONVERTER APPROACH AND THE APPLICATION OF APPROXIMATE ENTROPY AS POST CLASSIFIER FOR THE CLASSIFICATION OF EPILEPSY RISK LEVELS FROM EEG SIGNALS

ABSTRACTObjective: The electroencephalogram (EEG) is actually a measure of the cumulative firing of neurons in various parts of the brain. The EEG containsthe information with regard to the changes in the electrical potential of the brain which is obtained from a set of recording electrodes. The aim of thispaper is to give a performance analysis by considering the advantage of Code Converter technique and Approximated Entropy (ApEn) is used as a postclassifier for the classification of the epilepsy risk levels obtained from EEG signals.Methods: The Data Acquisition of EEG signals are done initially from the hospital. Then the code converter approach is presented, as working ondefinite alphabets is much easier when compared to that of working on numericals. Finally, ApEn is used as a Post Classifier for the classification ofepilepsy risk levels from EEG signals.Results: The Performance Index and Quality Values are the two important parameters that are used to assess the performance of the Code Convertersand the Classifier. The Perfect Classification rate of 83.94% is achieved along with an Accuracy of 91.97% and a Quality Value of 18.5.Conclusion: The computation of this procedure seems to be very simple and versatile. Future works may use different Dimensionality Reductiontechniques to analyze its performance with Approximated Entropy as Post Classifier.Keywords: Electroencephalogram signals, Code converter, Performance index, Quality values

Role of oxygen transients in the facile scission of C–O bonds of alcohols on Zn surfaces

The alkoxy species produced by the interaction of alcohols with Zn surfaces undergoes C–O bond scission at 150 K giving hydrocarbon species, but this transformation occurs even at 80 K when alcohol–oxygen mixtures are coadsorbed, due to the oxygen transients

Massive Gauge Axion Fields

A gauge invariant formulation for the massive axion is considered. The axion acquires mass through a topological term which couples a (pseudo)scalar and a third rank antisymmetric tensor. Duality, local and canonical equivalences with the non-gauge invariant proposal are established. The supersymmetric version of the gauge invariant model is constructed.Comment: Final version. New references adde