This manuscript explores the compact geometries by employing Karmarkar condition with the charged anisotropic source of matter distribution. For this purpose, we consider an explicit model by indulging <math><msub><mrow><mi>g</mi></mrow><mrow><mi>r</mi><mi>r</mi></mrow></msub></math> metric potential obeying the Karmarkar condition. Moreover, we ansatz the time metric co-efficient following the approach by Adler [1]. The crucial aspect of present investigation is the implication of the Bardeen model as an outer spacetime [2]. Implementation of Bardeen approach turns out to be very interesting as this corresponds to the magnetic mono-pole gravitational remnants emerging from some particular non-linear electrodynamics. Detailed analysis supported by their corresponding plots of the profiles of the pressure profiles, energy density, charged density, anisotropy function, electric field attributes, energy bounds, redshift function, compactness parameter, stability and adiabatic index has been provided. It is important to mention here that our obtained solutions are physically viable and are well stable.

Pakistan

M. Farasat Shamir

China

G. Mustafa

Mushtaq Ahmad

Charged anisotropic Finch-Skea-Bardeen spheres

This work suggests a new model for anisotropic compact stars with quintessence in   $f(T)$   gravity by using the off-diagonal tetrad and the power-law as   $f(T)$  , where T is the scalar torsion and   $f(T)$   and n are real constants. The acquired field equations incorporating the anisotropic matter source along with the quintessence field, in   $f(T)$   gravity, are investigated by making use of the specific character of the scalar torsion T for the observed stars   $f(T)$  ,   $f(T)$  ,   $f(T)$  ,   $f(T)$  , and   $f(T)$  . It is suggested that all the stellar structures under examination are advantageously independent of any central singularity and are stable. Comprehensive graphical analysis shows that various physical features which are crucially important for the emergence of the stellar structures are conferred.

Allah Ditta

Ibrar Hussain

Anisotropic stellar structures in the Theory of Gravity With Quintessence via Embedding Approach

The possible emergence of compact stars has been investigated in the recently introduced modified Gauss–Bonnet $$f(\mathcal {G},T)$$ <math><mrow><mi>f</mi><mo>(</mo><mi>G</mi><mo>,</mo><mi>T</mi><mo>)</mo></mrow></math>  gravity, where $$\mathcal {G}$$ <math><mi>G</mi></math>  is the Gauss–Bonnet term and T is the trace of the energy-momentum tensor (Sharif and Ikram, Eur Phys J C 76:640, 2016). Specifically, for this modified $$f(\mathcal {G}, T)$$ <math><mrow><mi>f</mi><mo>(</mo><mi>G</mi><mo>,</mo><mi>T</mi><mo>)</mo></mrow></math>  theory, the analytic solutions of Krori and Barua have been applied to an anisotropic matter distribution. To determine the unknown constants appearing in the Krori and Barua metric, the well-known three models of the compact stars, namely 4U1820-30, Her X-I, and SAX J 1808.4-3658 have been used. The analysis of the physical behaviour of the compact stars has been presented and the physical features like energy density and pressure, energy conditions, static equilibrium, stability, measure of anisotropy, and regularity of the compact stars, have been discussed.

M. Shamir

Emerging anisotropic compact stars in $$f(\mathcal {G},T)$$ <math><mrow><mi>f</mi><mo>(</mo><mi>G</mi><mo>,</mo><mi>T</mi><mo>)</mo></mrow></math>  gravity

We explore the recently introduced modified Gauss–Bonnet gravity (Sharif and Ikram in Eur Phys J C 76:640, 2016 ), f(G,T) pragmatic with G , the Gauss–Bonnet term, and T , the trace of the energy-momentum tensor. Noether symmetry approach has been used to develop some cosmologically viable f(G,T) gravity models. The Noether equations of modified gravity are reported for flat FRW universe. Two specific models have been studied to determine the conserved quantities and exact solutions. In particular, the well known deSitter solution is reconstructed for some specific choice of f(G,T) gravity model.