Distance, reddening and three dimensional structure of the SMC - I: Using RRab stars

We present a study of simultaneous determination of mean distance and reddening to the Small Magellanic Cloud (SMC) using the two photometric band RR Lyrae data. Currently available largest number of highly accurate and precise light curve data of the fundamental mode RR Lyrae stars (RRab) with better areal coverage released by the Optical Gravitational Lensing Experiment (OGLE)-IV project observed in the two photometric bands $(V,I)$ were utilised simultaneously in order to determine true distance and reddening independently for each of the individual RRab stars. Different empirical and theoretical calibrations leading to the determination of absolute magnitudes of RRab stars in the two bands, $V$ and $I$ along with their mean magnitudes were utilised to calculate the apparent distance moduli of each of these RRab stars in these two bands. Decomposing the apparent distance moduli into true distance modulus and reddening in each of these two bands, individual RRab distance and reddening were estimated solving the two apparent distance moduli equations. Modeling the observed distributions of the true distance moduli and reddenings of the SMC RRab stars as Gaussian, the true mean distance modulus and mean reddening value to the SMC were found to be {\bf $\mu_{0}=18.909\pm0.148$ mag and $E(B-V)=0.066\pm0.036$ mag, respectively. This corresponds to a distance of $D = 60.506\pm 4.126$~kpc to the SMC. The three dimensional distribution of the SMC RRab stars was approximated as ellipsoid. Then using the principal axes transformation method \citep{deb14} we find the axes ratios of the SMC: $1.000\pm0.001,1.113\pm 0.002, 2.986\pm0.023$ with $i=3^{\circ}.156\pm0^{\circ}.188$ and $\theta_{\text{lon}}=38^{\circ}.027\pm0.577$.} These results are in agreement with other recent independent previous studies using different tracers and methodologies.Comment: 20 pages, 15 figures, Revised version resubmitted to MNRAS Main Journal on October 22, 201

A Hybrid Profile-Gradient Approach for the Estimation of Surface Fluxes

The Monin--Obukhov similarity theory-based wind speed and potential temperature profiles are inherently coupled to each other. We have developed hybrid approaches to disentangle them, and as a direct consequence, the estimation of Obukhov length (and associated turbulent fluxes) from either wind-speed or temperature measurements becomes an effortless task. Additionally, our approaches give rise to two easily measurable indices of atmospheric stability. We compare these approaches with the traditional gradient and profile methods that require both wind-speed and temperature profile data. Using Monte-Carlo-type numerical experiments we demonstrate that, if the input profiles are free of any random errors, the performance of the proposed hybrid approaches is almost equivalent to the profile method and better than the gradient method. However, the proposed hybrid approaches are less competitive in comparison to their traditional counterparts in the presence of random errors

Pseudo Fuzzy Set

Here a novel idea to handle imprecise or vague set viz. Pseudo fuzzy set has been proposed. Pseudo fuzzy set is a triplet of element and its two membership functions. Both the membership functions may or may not be dependent. The hypothesis is that every positive sense has some negative sense. So, one membership function has been considered as positive and another as negative. Considering this concept, here the development of Pseudo fuzzy set and its property along with Pseudo fuzzy numbers has been discussed

Finite Temperature Effects and Axion Cosmology

We investigate the impact of finite temperature effects on axions in the context of cosmology. The temperature dependence of the decay constant is modeled analogous to pions. For the two interesting cases considered here, we find that the temperature effects do lead to changes relevant for detailed and precise abundance and rate calculations. We also find that the axion decoupling temperature starts showing large deviations for larger values of the axion decay constant.Comment: 9 pages, 2 figure

Quantum aspects of antisymmetric tensor field with spontaneous Lorentz violation

We study the quantization of a simple model of antisymmetric tensor field with spontaneous Lorentz violation in curved spacetime. We evaluate the 1-loop corrections at first order of metric perturbation, using a general covariant effective action approach. We revisit the issue of quantum equivalence, and find that it holds for non-Lorentz-violating modes but breaks down for Lorentz violating modes.Comment: 20 pages; minor corrections, text improvements, references added; published versio

Preparations for detecting and characterizing gravitational-wave signals from binary black hole coalescences

We evaluate how well EOBNR waveforms, obtained from the effective one-body formalism, perform in detecting gravitational wave (GW) signals from binary black hole (BBH) coalescences modelled by numerical relativity (NR) groups participating in the second edition of the numerical injection analysis (NINJA-2). In this study, NINJA-2 NR-based signals that are available in the public domain were injected in simulated Gaussian, stationary data prepared for three LIGO-Virgo detectors with early Advanced LIGO sensitivities. Here we studied only non-spinning BBH signals. A total of 2000 such signals from 20 NR-based signal families were injected in a two-month long data set. The all-sky, all-time compact binary coalescence (CBC) search pipeline was run along with an added coherent stage to search for those signals. We find that the EOBNR templates are only slightly less efficient (by a few percent) in detecting non-spinning NR-based signals than in detecting EOBNR injections. On the other hand, the coherent stage improves the signal detectability by a few percent over a coincident search

On Number Conservation of Non-uniform Cellular Automata

This paper studies the number conservation property of 1-dimensional non-uniform cellular automata (CAs). In a non-uniform cellular automaton (CA), different cells may follow different rules. The present work considers that the cells follow Wolfram's CAs rules. A characterization tool, named Reachability tree is used to discover the number conservation property of non-uniform CAs. Then a decision algorithm is reported to conclude whether a given non-uniform CA with $n$ cells is number conserving or not. Finally, a synthesis scheme is developed to get an $n$-cell number conserving non-uniform CA

Numerical Solution of Fuzzy Stochastic Differential Equation

In this paper an alternative approach to solve uncertain Stochastic Differential Equation (SDE) is proposed. This uncertainty occurs due to the involved parameters in system and these are considered as Triangular Fuzzy Numbers (TFN). Here the proposed fuzzy arithmetic in [2] is used as a tool to handle Fuzzy Stochastic Differential Equation (FSDE). In particular, a system of Ito stochastic differential equations is analysed with fuzzy parameters. Further exact and Euler Maruyama approximation methods with fuzzy values are demonstrated and solved some standard SDE

Probing Low-x QCD With Very High Energy Prompt Muons

We explore the possibility of utilizing the prompt muon fluxes at very high energies in order to discriminate various models/parametrizations of low-x QCD behaviour of hadronic cross-sections relevant at such energies. We find that the pair meter technique for measuring high energy prompt muons can be very efficient in such an endeavor. As a by product, it allows to cleanly probe the change in composition of the primary cosmic rays expected at high energies.Comment: 5 pages, 2 figure

Reversibility of d-State Finite Cellular Automata

This paper investigates reversibility properties of 1-dimensional 3-neighborhood d-state finite cellular automata (CAs) of length n under periodic boundary condition. A tool named reachability tree has been developed from de Bruijn graph which represents all possible reachable configurations of an n-cell CA. This tool has been used to test reversibility of CAs. We have identified a large set of reversible CAs using this tool by following some greedy strategies.Comment: Copyright of Old City Publishin