Probing the densest objects in the universe
We are a research group at the National Institute of Technology, Rourkela, India — working at the intersection of nuclear physics, astrophysics, gravitational waves, and dark matter to unravel the mysteries of neutron stars.
Selected results
Figures from NAP Lab publications — click a paper link below each image to open the work.
Dr. Bharat Kumar
Bharat Kumar
Assistant Professor · Department of Physics & Astronomy, NIT Rourkela · since June 2020
M.Sc. Physics, AMU Aligarh · Ph.D. with S K Patra, IOP Bhubaneswar · Postdoc with Sukanta Bose (LIGO-India, IUCAA) · Postdoc with Takashi Nakatsukasa, University of Tsukuba, Japan
Citation count last verified via Google Scholar ↗ — click through for live, up-to-the-minute numbers.
Latest in neutron-star & GW astrophysics
Hand-picked recent developments in dense matter, gravitational-wave astronomy, and dark matter searches — updated periodically by the lab.
GWTC-4.0 catalog more than doubles GW detections
The LVK collaboration released GWTC-4.0, adding 128 new confirmed events from the second half of O4 and bringing the all-time total past 390 confirmed mergers, including new black hole–neutron star systems.
Construction begins on LIGO-India detector
Civil construction started in April 2026 on the LIGO-India facility, which will become the fifth major gravitational-wave interferometer and is projected to join the global network for the O5 run.
Mirror dark matter effects on NS tidal deformability
Jiao & Li construct a hadron–quark equation of state combined with mirror dark matter and show how the dark sector modifies tidal Love numbers and the 2M☉ constraint via Maxwell construction.
Probing NS equation of state via EMRIs in dark matter spikes
Karydas & collaborators show that LISA-band extreme mass-ratio inspirals through dense dark matter environments can, at high SNR, discriminate between neutron-star equations of state via relativistic dynamical friction.
Strongly-interacting dark matter admixed neutron stars
Dengler, Kulkarni, Maas & Radl use lattice QCD-like G2-gauge equations of state for strongly self-interacting dark matter and find masses of a few hundred MeV–GeV remain consistent with observed NS properties.
Intermediate Run IR1 planned for late 2026
LIGO, Virgo, and KAGRA are preparing a six-month intermediate observing run (IR1) beginning around October–November 2026, as a bridge toward the long-awaited O5 run with improved sensitivity.
For the very latest preprints see arXiv:astro-ph.HE ↗, nucl-th ↗, and LIGO News ↗
News
Congratulations to Pinku Routaray for successfully defending his PhD thesis and joining the Kavli Institute of Astronomy and Astrophysics, China as a postdoc!
Congrats to Pinku for Best Poster Award at the DAE High Energy Physics Symposium, BHU. Event ↗
Paper by Kalita, Routaray, Ghosh & Kumar on delta-baryons published in JCAP ↗
Pinku's paper on WIMP dark matter accepted in MNRAS ↗
Upcoming events
GWsNS-2026 — Gravitational Waves from Neutron Stars school, Roscoff, France.
Asian GW Astronomy Meeting (AGWAM 2026) — Chiang Mai, Thailand.
Multimessenger Astrophysics 2026 — 9th ICE Summer School, Barcelona, Spain.
Erice School — Neutrinos in Cosmology, Astro-, Particle & Nuclear Physics, Erice, Italy.
Current team members
PhD Students
Sayantan Ghosh
M.Sc., Banaras Hindu University
Selected publications
Probing the Impact of Delta-Baryons on Nuclear Matter and Non-Radial Oscillations in Neutron Stars
The Role of Adiabatic Sound Speeds in Neutron Star Radial Oscillations and Stability
Observable Signatures of a Quarkyonic Phase in Neutron Stars
Spacetime Curvature as a Probe of Exotic Core Phases in Neutron Stars within Modified Gravity
Join us
PhD Fellowship (DST WISE)
Positions in neutron star asteroseismology, dark matter admixed NSs, and multi-messenger astrophysics.
Apply via DST WISE ↗SERB-NPDF Fellowship
Postdoc in nuclear astrophysics, GW oscillations, or EoS constraints with LIGO/NICER data.
Apply via SERB ↗Own Fellowship? Join Us
If you have an external fellowship and wish to pursue research with us, get in touch directly.
kumarbh@nitrkl.ac.in ↗Contact
Dr. Bharat KumarMC202, Department of Physics & Astronomy
National Institute of Technology, Rourkela
Odisha 769008, India
Email: kumarbh@nitrkl.ac.in
Maps ↗
Support
Supported by the Science and Engineering Research Board (SERB), Government of India.
Part of the Department of Physics and Astronomy, NIT Rourkela.
