Aspects of Noncommutative Scalar/Tensor Duality

We study the noncommutative massless Kalb-Ramond gauge field coupled to a dynamical U(1) gauge field in the adjoint representation together with a compensating vector field. We derive the Seiberg-Witten map and obtain the corresponding mapped action to first order in $\theta$. The (emergent) gravity structure found in other situations is not present here. The off-shell dual scalar theory is derived and it does not coincide with the Seiberg-Witten mapped scalar theory. Dispersion relations are also discussed. The p-form generalization of the Seiberg-Witten map to order $\theta$ is also derived.Comment: 7 pages, typos corrected, a footnote removed and a sentence added in the tex

Clinical profile of dengue fever in a tertiary care centre in North Kerala

Background: Dengue fever is the most common arboviral disease and fifty percent of world population is at risk. Frequent outbreaks are reported from all states of our country and incidence increases every year. This case study is of 305 patients from Academy of Medical Sciences, which is a tertiary care centre and research Institute in North Kerala. The objective of this study was to study the clinical profile of dengue fever.Methods: Study was prospective observational study conducted during the epidemic for a period of one year. All the cases which fulfilled WHO criteria for diagnosis of dengue fever and those who are positive for IGM antibody detected by enzymelinked immunosorbent assay (IgM ELISA) were only included in this study.Results: There is male preponderance, and those above the age of 30 years affected more. All patients had fever. Gastrointestinal manifestation like nausea and vomiting were commonly observed symptoms. Hepatomegaly, rash and conjuctival suffusion were important physical findings, whereas splenomegaly noted only in 8.2% cases. Thrombocytopenia is noticed in 73.96%.Conclusions: The mortality is 2.6%. Hypotension and thrombocytopenia are the two important determinants of mortality. Dengue Shock syndrome and Dengue Hemorrhagic Fever were relatively less when compared to other epidemics from different regions

Optimal time-domain combination of the two calibrated output quadratures of GEO 600

GEO 600 is an interferometric gravitational wave detector with a 600 m arm-length and which uses a dual-recycled optical configuration to give enhanced sensitivity over certain frequencies in the detection band. Due to the dual-recycling, GEO 600 has two main output signals, both of which potentially contain gravitational wave signals. These two outputs are calibrated to strain using a time-domain method. In order to simplify the analysis of the GEO 600 data set, it is desirable to combine these two calibrated outputs to form a single strain signal that has optimal signal-to-noise ratio across the detection band. This paper describes a time-domain method for doing this combination. The method presented is similar to one developed for optimally combining the outputs of two colocated gravitational wave detectors. In the scheme presented in this paper, some simplifications are made to allow its implementation using time-domain methods

Generative Model for Conceptual Design of Defence Equipment

Requirement study and analysis forms a key component in conceptual design of new products and systems. For complex systems like defence equipment, concept design is very important and should primarily satisfy all user requirements. Brings out a new generative model for concept design of defence systems using principles of systems engineering. A structured model and methodology is presented starting from capturing the user requirements, developing multiple solutions, short listing the candidate solutions and finally selecting one or two feasible designs. The model and process is illustrated with the help of a case study on the development of a torpedo defence system for naval ships.

Physical instrumental vetoes for gravitational-wave burst triggers

We present a robust strategy to \emph{veto} certain classes of instrumental glitches that appear at the output of interferometric gravitational-wave (GW) detectors.This veto method is `physical' in the sense that, in order to veto a burst trigger, we make use of our knowledge of the coupling of different detector subsystems to the main detector output. The main idea behind this method is that the noise in an instrumental channel X can be \emph{transferred} to the detector output (channel H) using the \emph{transfer function} from X to H, provided the noise coupling is \emph{linear} and the transfer function is \emph{unique}. If a non-stationarity in channel H is causally related to one in channel X, the two have to be consistent with the transfer function. We formulate two methods for testing the consistency between the burst triggers in channel X and channel H. One method makes use of the \emph{null-stream} constructed from channel H and the \emph{transferred} channel X, and the second involves cross-correlating the two. We demonstrate the efficiency of the veto by `injecting' instrumental glitches in the hardware of the GEO 600 detector. The \emph{veto safety} is demonstrated by performing GW-like hardware injections. We also show an example application of this method using 5 days of data from the fifth science run of GEO 600. The method is found to have very high veto efficiency with a very low accidental veto rate.Comment: Minor changes, To appear in Phys. Rev.

Dual Linearised Gravity in Arbitrary Dimensions

We construct dual formulation of linearised gravity in first order tetrad formalism in arbitrary dimensions within the path integral framework following the standard duality algorithm making use of the global shift symmetry of the tetrad field. The dual partition function is in terms of the (mixed symmetric) tensor field $\Phi_{[\nu_{1}\nu_{2}...\nu_{d-3}]\nu}$ in {\it frame-like} formulation. We obtain in d-dimensions the dual Lagrangian in a closed form in terms of field strength of the dual frame-like field. Next by coupling a source with the (linear) Riemann tensor in d-dimensions, dual generating functional is obtained. Using this an operator mapping between (linear) Riemann tensor and Riemann tensor corresponding to the dual field is derived and we also discuss the exchange of equations of motion and Bianchi identity.Comment: 14 pages, typos corrected, Published version: Class. Quantum Grav. 22(2005)538