RK

Rahul Kumar

Also known as: Rahul Kumar Walia

Netaji Subhas University of Technology, University College London, University of Arizona

ORCID iD 0000-0003-2471-1360
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About

I am a Royal Society Newton International Fellow at University College London (UCL), UK. Before joining UCL, I was a Fulbright-Nehru Postdoctoral Research Fellow at the University of Arizona, USA, from 2023 to 2025.
I am also working as an Assistant Professor in the Department of Physics at Netaji Subhas University of Technology (NSUT), Delhi, India.

My research seeks to understand the fundamental nature of gravity and black holes in the strong-field regime by bridging theoretical physics, astrophysical modeling, and horizon-scale observations. I develop and test models of black holes and horizonless ultra-compact objects in General Relativity and alternative theories of gravity, translating their spacetime properties into measurable signatures through strong gravitational lensing, accretion-flow modeling, general-relativistic radiative transfer (GRRT), and horizon-scale imaging. Using semi-analytic and numerical methods, including multi-frequency polarized radiative transfer and general-relativistic magnetohydrodynamic (GRMHD) simulations, I model compact-object environments and their variable phenomena, including flares, outflows, and transients, to enable robust interpretation of observational data. By connecting these predictions with the EHT, ngEHT, and BHEX, my work develops precision tests of General Relativity, alternative gravity theories, the Kerr paradigm, exotic matter fields, and black-hole mimickers. Complementing this observational program, I am interested in investigating quasinormal modes and stability, phase transitions, and quantum aspects of black holes to probe the nature of horizons and compact objects under extreme gravitational conditions.

Employment

  • Netaji Subhas University of Technology Assistant Professor
    2026 - Present
  • University College London Royal Society Newton International Fellow
    2026 - 2028
  • University of Arizona Fulbright-Nehru Postdoctoral Fellow
    2023 - 2025
  • University of KwaZulu-Natal Post Doctoral Fellow
    2021 - 2023

Education

Education history is unavailable.

Projects & Funding

Projects & funding information is unavailable.

Publications (64)