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  • d−α Radiative capture process by effective field theory
    New Astron. (IF 1.162) Pub Date : 2020-05-23
    S. Nahidinezhad; H. Sadeghi; H. Khalili

    Two of the main components of nuclear fusion processes which occur in stars are the radiative capture of deuteron-alpha and its inverse reaction during which helium transforms into larger elements. One of the reactions occuring is the production of 6Li through the d(α, γ)6Li reaction that is supported by the Big Bang model. The process of radiation in the energy region 0.07 MeV ≤ Ecm ≤ 0.41 MeV has

  • Redshift Drift in f(R, T) Gravity
    New Astron. (IF 1.162) Pub Date : 2020-05-23
    Snehasish Bhattacharjee; P.K. Sahoo

    Redshift drift refers to the phenomena that redshift of cosmic objects is a function of time. Measurement of redshift drift is of fundamental importance in physical cosmology and can be utilized to distinguish different cosmological models. Redshift drift can be expressed in two distinct methods. The first method is related to cosmography, where the Redshift drift is given as a series expansion of

  • Relativistic parametric embedding class I solutions of cold stars in Karmarkar space-time continuum
    New Astron. (IF 1.162) Pub Date : 2020-05-19
    Jaya Upreti; Satyanarayana Gedela; Neeraj Pant; R.P. Pant

    The aim of this paper is to explore a new parametric class of relativistic solutions to the Einstein field equations describing a spherically symmetric, static distribution of anisotropic fluid spheres to study the behavior of some of the cold stars in the setting of Karmarkar space-time continuum. We develop models of stellar objects for a range of parameter values of n and analyze their behavior

  • Holographic Dark Energy Cosmological Models in f(G) Theory
    New Astron. (IF 1.162) Pub Date : 2020-05-17
    A.Y. Shaikh; S.V. Gore; S.D. Katore

    In this paper, Locally Rotationally Symmetric (LRS) Bianchi type-I models with holographic dark energy within the framework of f(G) theory of gravitation are thought about. So as to get determinate solutions, volumetric exponential expansion, power law expansion and hybrid expansion law are mentioned. The physical interpretations of the solution have been studied by using some physical quantizes. Additionally

  • A robust determination of halo environment in the cosmic field
    New Astron. (IF 1.162) Pub Date : 2020-05-15
    Peng Wang; Xi Kang; Noam I. Libeskind; Quan Guo; Stefan Gottlöber; Wei Wang

    A number of methods for studying the large-scale cosmic matter distribution exist in the literature. One particularly common method employed to define the cosmic web is to examine the density, velocity or potential field. Such methods are advantageous since a Hessian matrix can be constructed whose eigenvectors (and eigenvalues) indicate the principal directions (and strength) of local collapse or

  • A photometric study of HAT 141-03513: another twin of the V361 Lyr system
    New Astron. (IF 1.162) Pub Date : 2020-05-15
    M. Wolf; H. Kučáková

    The BVRI light curves were measured for the eclipsing binary HAT 141-03513 as a part of our long-term observational project for studying low-mass eclipsing binaries with a short orbital period. The asymmetric light curve and the difference in brightness in maxima, are probably the result of presence of a hot region on the surface of one component. The light curve solution in Phoebe results to the semidetached

  • Statefinder diagnostic for the Re´nyi holographic dark energy
    New Astron. (IF 1.162) Pub Date : 2020-05-13
    Umesh Kumar Sharma; Vipin Chandra Dubey

    In this paper, we have examined the Re´nyi holographic dark energy (RHDE) model in the framework of flat FRW universe by considering different values of non - extensive parameter δ. The deceleration parameter (q) of RHDE model justifies the recent phase transition of cosmos because of q changes sign from +ve to −ve i.e. deceleration to accelerated phase. We calculated and plotted the trajectories of

  • Wormhole model with a hybrid shape function in f(R, T) gravity
    New Astron. (IF 1.162) Pub Date : 2020-05-12
    Parbati Sahoo; Sanjay Mandal; P.K. Sahoo

    In the present article we propose a new hybrid shape function for wormhole (WH)s in the modified f(R, T) gravity. The proposed shape function satisfied the conditions of WH geometry. Geometrical behavior of WH solutions are discussed in both anisotropic and isotropic cases respectively. Also, the stability of this model is obtained by determining the equilibrium condition. The radial null energy condition

  • Random fragmentation of turbulent molecular clouds lying in the central region of giant galaxies
    New Astron. (IF 1.162) Pub Date : 2020-05-12
    Suman Paul; Tanuka Chattopadhyay

    A stochastic model of fragmentation of molecular clouds has been developed for studying the resulting Initial Mass Function (IMF) where the number of fragments, inter-occurrence time of fragmentation, masses and velocities of the fragments are random variables. Here two turbulent patterns of the velocities of the fragments have been considered, namely, Gaussian and Gamma distributions. It is found

  • Some Bianchi Type Cosmological Models in f(R, ϕ) Gravity
    New Astron. (IF 1.162) Pub Date : 2020-05-12
    Adnan Malik; Shahzad Ahmed; Saqib Mahmood

    In this paper, we study three different Bianchi type line elements, like Bianchi type-I (BT-I), Bianchi type-III (BT-III) and Kantowski Sachs space-time in the framework of f(R, ϕ) theory of gravity, where R and ϕ represent the Ricci scalar and the scalar potential function respectively. We find the exact solution of vacuum field equations of f(R, ϕ) theory by taking valuable assumption that the expansion

  • The study of Gödel type solutions in f(R, ϕ) gravity
    New Astron. (IF 1.162) Pub Date : 2020-05-12
    Adnan Malik; M. Farasat Shamir

    The aim of this paper is to study the Gödel type universe in modified f(R, ϕ) theory of gravity, where R stands for Ricci scalar and ϕ be the scalar potential. We investigate the modified field equations by using anisotropic and perfect fluid distributions. In particular, we consider two proposed models with some fixed values of parameters and investigate the exact solutions. The behaviour of energy

  • Age and Metallicity of galaxies in different environments of the Coma supercluster
    New Astron. (IF 1.162) Pub Date : 2020-05-11
    Juhi Tiwari; Smriti Mahajan; Kulinder Pal Singh

    We analyse luminosity-weighted ages and metallicity (Z) of galaxies in a continuous range of environments, i.e. clusters, filaments and voids prevalent in the Coma supercluster (∼100h−1 Mpc). Specifically, we employ two absorption line indices, Hβ and ⟨Fe⟩ as tracers of age and metallicity of galaxies. We find that the stellar-phase metallicity of galaxies declines with increasing age as a function

  • First study of a low-amplitude eclipsing binary KIC11496078
    New Astron. (IF 1.162) Pub Date : 2020-05-06
    S. Soomandar; A. Abedi

    We investigate a low-amplitude W UMa binary KIC 11496078 based on Kepler photometric data, and the diagrams of OC maxima and minima of light curves are plotted. The anti-correlated nature of the curves indicates that KIC 11496078 is a binary. We use short cadence mode (SC) data for analyzing the light curve. By performing some analyses, the parameters of the system are determined. The results show

  • New CCD photometry and light curve analysis of two WUMaBinaries: 1SWASP J133417.80+394314.4 and V2790 Orion
    New Astron. (IF 1.162) Pub Date : 2020-05-04
    A. Shokry; I.Z. Zead; M.H. El-Depsey; M.S. Darwish; I.A. Hassan; A.M.K. Shaltout; M.S. Saad; M.I. Nouh

    We present a new multicolor CCD photometry and light curve analysis of two eclipsing binary systems, 1SWASP J133417.80 + 394314.4 and V2790 Orion. The photometric solutions for both binaries were carried out using the updated version of the Wilson– Devinney code. The results showed that first systems is A- type W UMa with mass ratios q = 0.158 while the second system is W- type with q = 3.2. The systems

  • Crossing the phantom divide line in universal extra dimensions
    New Astron. (IF 1.162) Pub Date : 2020-05-01
    Nasr Ahmed; Anirudh Pradhan

    We investigate the cosmic acceleration and the evolution of dark energy across the cosmological constant boundary in universal extra dimensions UED. We adopt an empirical approach to solve the higher-dimensional cosmological equations so that the deceleration parameter q is consistent with observations. The expressions for the jerk and deceleration parameters are independent of the number of dimensions

  • Multiwavelength study of the radio galaxy NGC 1275 with TACTIC, Fermi and Swift during December, 2016 – February, 2017
    New Astron. (IF 1.162) Pub Date : 2020-04-28
    B. Ghosal; A. Tolamatti; K.K. Singh; K.K. Yadav; R.C. Rannot; A.K. Tickoo; P. Chandra; A. Goyal; N. Kumar; P. Marandi; N.K. Agarwal; M. Kothari; K.K. Gaur; N. Chouhan; C. Borwankar; V.K. Dhar; M.K. Koul; K. Venugopal; M. Sharma

    Located in the Perseus galaxy cluster, NGC 1275 (z=0.0179), is the brightest radio galaxy detected in both high energy (HE ; E > 100 MeV) and very high energy (VHE ; E > 100 GeV) regimes. Here we present the results from the observations of NGC 1275 with TACTIC for 37.1 h between December, 2016 and February, 2017. In the absence of a statistically significant VHE γ-ray detection from the TACTIC observations

  • First photometric investigation of two short-period eclipsing binaries NSVS 7377756 and for UCAC3 276-106147
    New Astron. (IF 1.162) Pub Date : 2020-04-28
    Carlo Barani; Massimiliano Martignoni; Francesco Acerbi

    We present the first CCD sets of complete light curves for two W Ursae Majoris Systems, UCAC3 276-106147 and NSVS 7377756. These light curves are here analyzed and modelled using the latest version of the Wilson-Devinney Code. We found that UCAC3 276-106147 is a W-subtype shallow-contact eclipsing binary (fill-out factor 7.5%), with a mass ratio of q = 2.88 (1/q = 0.347), a small temperature difference

  • Traversable wormholes in f(R) gravity with constant and variable redshift functions
    New Astron. (IF 1.162) Pub Date : 2020-04-15
    Nisha Godani; Gauranga C. Samanta

    The present paper is aimed at the study of traversable wormholes in f(R) gravity with a viable f(R) function defined as f(R)=R−μRc(RRc)p, where R is scalar curvature, μ, Rc and p are constants with μ, Rc > 0 and 0 < p < 1 (Amendola et al., 2007a). The metric of wormhole is dependent on shape function b(r) and redshift function ϕ(r), which characterize its properties, so the shape function and redshift

  • Elliptic Sitnikov five-body problem under radiation pressure
    New Astron. (IF 1.162) Pub Date : 2020-04-17
    M. Shahbaz Ullah; M. Javed Idrisi; Vinay Kumar

    We consider the square configuration of photo-gravitational elliptic restricted five-body problem and study the Sitnikov motions. The four radiating primaries are of equal mass placed at the vertices of square and the fifth body having negligible mass performs oscillations along a straight line perpendicular to the orbital plane of the primaries. The motion of the fifth body is called vertical periodic

  • Effects of electromagnetic field on the stability of locally isotropic gravastars
    New Astron. (IF 1.162) Pub Date : 2020-04-22
    K. Majeed; Z. Yousaf; G. Abbas

    We have studied a new solution of charged gravastars with isotropic matter configuration in the framework of f(R, T) theory of gravity. For this purpose, we have assumed the electric charge as a constant. This stellar structure divided into three different regions: The preliminary part shows the interior charged region in which pressure equals to the negative density, second is the intermediate charged

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