Publications
Group highlights
At the end of this page, you can find the full list of publications. All papers are also available on Google Scholar.
In this work, we explored the influence of WIMPs dark matter on neutron stars and universal relations. Investigating the interactions of trapped neutralinos with hadronic matter via Higgs boson exchange within the Next-to-Minimal Supersymmetric Standard Model, the study found that dark matter softened the equation of state, causing shifts in posterior and mass-radius curves. It also maintained C–Λ universality relations, potentially classifying HESS J1731−347 as a dark matter-admixed neutron star.
Pinku Routaray, Abdul Quddus, Kabir Chakravarti, and Bharat Kumar
In our study of dark matter-admixed neutron stars within the relativistic mean-field model, we employ the IOPB-I hadronic equation of state, assuming the presence of fermionic dark matter. Our findings reveal that dark matter softens the equation of state, reducing both maximum mass and radius. Pulsating neutron stars with dark matter exhibit higher frequencies, indicating a linear correlation with the DM Fermi momentum. We also investigate eigenfunctions, stability criteria, and crust effects on frequency separation.
Pinku Routray, H. C. Das, Souhardya Sen, Bharat Kumar, Grigoris Panotopoulos, and Tianqi Zhao
Phys. Rev. D 107, 103039 (2023) [PDF]
We investigated neutron star equations of state and their impact on f- and p-mode oscillation frequencies within Cowling and linearized general relativity. We found strong correlations between these frequencies, nuclear matter properties, and the pressure of β-equilibrated matter at or near nuclear saturation density ρ0, regardless of star composition. Notably, the p1-mode frequency in a 1.4 M⊙ star correlated significantly with the slope of symmetry energy (L0) and β-equilibrated pressure at ρ0, shedding light on neutron star intricacies.
Athul Kunjipurayil, Tianqi Zhao, Bharat Kumar, Bijay K. Agrawal, and Madappa Prakash
Phys. Rev. D 106, 063005 (2022) [PDF]
We have used equation-of-state (EoS) insensitive relations between neutron star (NS) observables to translate the GW170817 canonical tidal deformability measurement into bounds on the properties of all neutron stars. In particular, if we assume a common neutron star EoS, then GW170817 constrains radii, moment-of-inertia and tidal deformability for other binary NS and pulsar systems. These quasi-universal relations can further be used to combine separate X-ray and GW observations independently of the EoS, leading to joint constraints on tidal deformability.
Bharat Kumar and Philippe Landry
Phys. Rev. D 99, 123026 (2019) [PDF]
We’ve developed G3 and IOPB-I parameter sets for energy density functions in finite nuclei and infinite nuclear matter, using effective field theory motivated relativistic mean field (ERMF) formalism. Our results align with experimental data, including the neutron-skin thickness of Pb-208 nucleus and neutron star radius from GW170817. Our low-density equation of state for pure neutron matter matches other models, and we also compute maximum mass and tidal deformability in agreement with GW170817 and pulsar data.
Bharat Kumar, S K Patra, and B K Agrawal
Phys. Rev. C 97, 045806 (2018) [PDF]
We found that the tidal deformability strongly correlates with the linear combinations of the slopes of nuclear isoscalar incompressibility and symmetry energy coefficients, all fall-outs of the nuclear equation of state. For the first time, we also found that the tidal deformability is approximately proportional to the sixth power of the radius of neutron star for a wide range of neutron star masses. This relation together with the bounds on the tidal deformability obtained from the GW170817 and its UV/optical/infrared electromagnetic counterparts constrain the radius of the neutron star with canonical mass in the range 11.82 - 13.72 km.
Philippe Landry and Bharat Kumar
ApJ Letter 868, L22 (2018) [PDF]
Full List of publications
Exploring the Macroscopic Properties and Nonradial Oscillations of Proto-Neutron Stars: Effects of Temperature, Entropy, and Lepton Fraction
Sayantan Ghosh, Shahebaj Shaikh, Probit J Kalita, Pinku Routaray, Bharat Kumar, B. K. Agrawal
arXiv
Exploring Radial Oscillations in Slow Stable and Hybrid Neutron Stars
Sayantan Ghosh, Sailesh Ranjan Mohanty, Tianqi Zhao, Bharat Kumar
arXiv
Probing the impact of Delta-Baryons on Nuclear Matter and Non-Radial Oscillations in Neutron Stars
Probit Jyoti Kalita, Pinku Routaray, Sayantan Ghosh, Bharat Kumar, and Bijay K. Agrawal
JCAP 04, 065 (2024) [PDF]
Dark Matter Admixed Neutron Star in the light of HESS J1731-347 and PSR J0952-0607
Pinku Routaray, H C Das, Jeet Amrit Pattnaik, Bharat Kumar
arXiv
Unstable Anisotropic Neutron Stars; Probing the Limits of Gravitational Collapse
Sailesh Ranjan Mohanty, Sayantan Ghosh, Pinku Routaray, H C Das, and Bharat Kumar
JCAP 03, 054 (2024) [PDF]
Investigating Dark Matter-Admixed Neutron Stars with NITR Equation of State in Light of PSR J0952-0607
Pinku Routaray, Sailesh Ranjan Mohanty, H.C. Das, Sayantan Ghosh, P.J. Kalita, V. Parmar, and Bharat Kumar
JCAP 10, 073 (2023) [PDF]
Probing the Impact of WIMP Dark Matter on Universal Relations, GW170817 Posterior and Radial Oscillations
Pinku Routaray, Abdul Quddus, Kabir Chakravarti, and Bharat Kumar
MNRAS 25, 5492 (2023) [PDF]
Radial Oscillations of Dark Matter admixed Neutron Stars
Pinku Routray, H. C. Das, Souhardya Sen, Bharat Kumar, Grigoris Panotopoulos, and Tianqi Zhao
Phys. Rev. D 107, 103039 (2023) [PDF]
Radial oscillations in neutron stars from unified equation of states
Souhardya Sen, Shubham Kumar, Athul Kunjipurayil, Pinku Routaray, Sayantan Ghosh, Probit J. Kalita, Tianqi Zhao and Bharat Kumar
Galaxies 11, 60 (2023) [PDF]
Theoretical studies on structural properties and decay modes of Z= 119 isotopes
Asloob A. Rather, M. Ikram, Ishfaq A. Rather, A. A. Usmani, Bharat Kumar, K. P. Santhosh, S. K. Patra
Eur. Phys. J. Plus 138, 467 (2023) [PDF]
Dark Matter Effects on the Compact Star Properties
H C Das, Ankit Kumar, Bharat Kumar, and S K Patra
Galaxies 10, 14 (2022) [Invited Review Article] [PDF]
Universal relations between the quasinormal modes of neutron star and tidal deformability
Hajime Sotani, and Bharat Kumar
Phys. Rev. D 104, 123002 (2021) [PDF]
The BigApple force and it’s implications to finite nuclei and astrophysical objects
H C Das, Ankit Kumar, Bharat Kumar, S K Biswal, and S K Patra
IJMP E 30, 2150088 (2021) [PDF]
Impacts of dark matter on the curvature of the neutron star
H C Das, Ankit Kumar, Bharat Kumar, S K Biswal, and S K Patra
JCAP 01, 007 (2021) [PDF]
Warm dense matter and cooling of supernovae remnants
Ankit Kumar, H C Das, S K Biswal, Bharat Kumar, and S K Patra
Eur. Phys. J C 80, 775 (2020) [PDF]
GW170817 constraints on the properties of a neutron star in the presence of WIMP dark matter
Abdul Quddus, Grigorios Panotopoulos, Bharat Kumar, Shakeb Ahmad, and S K Patra
J. Phys. G 47, 095202 (2020) PDF]
Effects of dark matter on the nuclear and neutron star matter
H C Das, Ankit Kumar, Bharat Kumar,S K Biswal, Takashi Nakatsukasa, Ang Li, and S K Patra
MNRAS 495, 4893 (2020) PDF]
Impact of the equation of state on f- and p- mode oscillations of neutron stars
Athul Kunjipurayil, Tianqi Zhao, Bharat Kumar, Bijay K. Agrawal, and Madappa Prakash
Phys. Rev. D 106, 063005 (2022) [PDF]
Inferring neutron star properties from GW170817 with universal relations
Bharat Kumar and Philippe Landry
Phys. Rev. D 99, 123026 (2019) [PDF]
New relativistic effective interaction for finite nuclei, infinite nuclear matter, and neutron stars
Bharat Kumar, S K Patra, and B K Agrawal
Phys. Rev. C 97, 045806 (2018) [PDF]
Constraints on the Moment of Inertia of PSR J0737-3039A from GW170817
Philippe Landry and Bharat Kumar
ApJ Letter 868, L22 (2018) [PDF]
GW170817 Constraining the nuclear matter equation of state from the neutron star tidal deformability
Tuhin Malik, N. Alam, M. Fortin, C. Providencia, B. K. Agrawal, T. K. Jha, Bharat Kumar, and S K Patra
Phys. Rev. C 98, 034005 (2018) [PDF]
Decay properties and reaction dynamics of zirconium isotopes
M. Panigrahi, R. N. Panda, Bharat Kumar, and S K Patra
IJMP E 27, 1850012 (2018) [PDF]
A Study of Multi-Lambda Hypernuclei within Spherical Relativistic Mean-field Approach
Asloob A. Rather, M. Ikram, A. A. Usmani, Bharat Kumar, and S. K. Patra
Braz. J. Phys. 47, 628 (2017) [PDF]
New parameterization of the effective field theory motivated relativistic mean-field model
Bharat Kumar, S. K. Singh, B. K. Agrawal, and S. K. Patra
Nucl. Phys. A 966, 197 (2017) [PDF]
Relative mass distributions of neutron-rich thermally fissile nuclei within statistical mode
Bharat Kumar, M. T. Senthil Kannan, M. Balasubramaniam, B. K. Agrawal, and S. K. Patra
Phys. Rev. C 96, 034623 (2017) [PDF]
Relative fragmentation in ternary systems within the temperature-dependent relativistic mean-field approach
M. T. Senthil Kannan, Bharat Kumar, M. Balasubramaniam, B. K. Agrawal, and S. K. Patra
Phys. Rev. C 95, 064613 (2017) [PDF]
Tidal deformability of neutron and hyperon star with relativistic mean-field equations of state
Asloob A. Rather, M. Ikram, A. A. Usmani, Bharat Kumar, and S. K. Patra
Eur. Phys. J. A 52, 372 (2016) [PDF]
Quest for magicity in hypernuclei
M. Ikram, Bharat Kumar, S. K. Biswal and S. K. Patra
IJMP E 25, 1650103 (2016) [PDF]
Effects of isovector scalar meson on neutron star both with and without hyperon
S. K. Biswal, Bharat Kumar, and S. K. Patra
IJMP E 25,1650090 (2016) [PDF]
Nuclear structure and decay properties of even–even nuclei in Z = 70-80 drip-line region
S. Mahapatro, C. Lahiri, Bharat Kumar, R. N. Mishra and S. K. Patra
IJMP E 25, 1650062 (2016) [PDF]
Modes of decay in neutron-rich nuclei
Bharat Kumar, S. K. Biswal, S. K. Singh, Chirashree Lahiri, and S. K. Patra
IJMP E 25,1650020 (2016) [PDF]
Examining the stability of thermally fissile Th and U isotopes
Bharat Kumar, S. K. Biswal,S. K. Singh and S. K. Patra
Phys. Rev. C 92, 054314 (2015) [PDF]
Properties of superheavy nuclei: Z = 124
M. S. Mehta, Harvinder Kaur, Bharat Kumar, and S. K. Patra
Phys. Rev. C 92, 054305 (2015) [PDF]
Shape co-existence and parity doublet in Zr isotopes
Bharat Kumar, S. K. Singh and S. K. Patra
IJMP E 24, 1550017 (2015) [PDF]