arXiv subjects

Samprity Das

Publications and source records attributed to Samprity Das.

3 recordsLinked to original sources

arXiv2026

Evolution of Realistic Neutron star in the framework of f (Q) gravity

This work analyses and evaluates a few realistic compact objects in the presence of a gravitational interaction between two particles with a nonmetricity $Q$. In the $f(Q)$ gravity framework, we have selected the anisotropic equation of motion and have determined $f(Q)$ to be a linear function of nonmetricity $Q$. To evaluate the field equations in our work, we have opted to employ the Krori-Barua metric. We calculated the anisotropic factor for each of the four compact objects and found that the anisotropic component is positive and increases monotonically and interpreted that the nuclear force can oppose the gravitational attraction. At last, the relationship between mass and radius has been determined and illustrated visually. We have noted that the compactness of the pulsars LMC X-4, SMC X-4, Cen X-3, and Vela X-1 is inside the Buchdahl's limit for varying values of $a$. This has led to the interpretation that these pulsars are neutron stars in a modified gravity background of $f(Q)$. In addition, we calculated the model mass and, using thirty distinct choices of $a$, ran the Chi-Square test to see if there was a noticeable difference between the observed and model-generated masses. We have also looked at how the surface redshift has changed over time and whether the compact objects in our model that were previously described are compact.

gr-qc↗

arXiv2026

Compact objects in AdS spacetime with exponential, quadratic and power-law bosonic mass profiles

This paper reports a study on the formation and physical characteristics of compacts stars in AdS spacetime within the framework of Bose-Einstein Condensate. Considering a Bose-Einstein condensate background at zero temperature this study works on total mass, compactness, surface redshift, density, pressure, adiabatic index and energy conditions. The bosonic mass has been taken as three distinct functions of radial coordinate in exponential form, quadratic form, and power law form. Our results reveal that the mass increases monotonically with radius and remains within observational limit for all the observationally motivated compact-star mass scales considered in this study and the compactness for all the cases is within Buchdahl's limit and hence it was confirmed that the configuration correspondence to compact stellar configuration models rather than forming a collapsing model. Both NEC and SEC are satisfied throughout the stellar interior and hence dynamical stability is ensured. Furthermore, the study also confirms the enhanced mass concentration near the outer region in the stellar models under consideration. Hence present study explores the physical properties and stability of compact bosonic configurations in AdS spacetime within a holographically motivated framework. The present analysis is primarily phenomenological and qualitative in nature. The models considered here are intended to explore possible behaviours of self-gravitating bosonic configurations in AdS geometry and are not proposed as fully realistic neutron-star models.

gr-qc↗

arXiv2024

Relativistic model of anisotropic star with Bose-Einstein density depiction in $f(T)$ gravity

This article presents a new model for anisotropic compact stars that are confined to physical dark matter in the background of $f(T)$ teleparallel gravity. The model is based on the equation of state (EoS) of the bag model type and the Bose-Einstein dark matter density profile. The derived solutions meet the energy conditions, the causality conditions, and the required conditions on the stability factor and adiabatic index, indicating that they are physically well-behaved and represent the physical and stable matter configuration. We also determine the maximum mass, surface redshift, and compactness parameter at the surface. Interestingly, all of these numbers fall within the specified range, supporting the physical viability of our proposal. Additionally, the various masses that are derived for varying the model parameter $k$ correspond to five compact, realistic compact objects, including LMC X-4, Her X-1, 4U 1538-52, SAX J1808.4-3658, and Cen X-3. We have also illustrated the radially symmetric profiles of energy density and the moment of inertia for non-rotating stars.

gr-qc↗