activity
20242026
collaborators

12 papers

gr-qc2026

Systematic Light Propagation Bias from the Heliosphere and Its Impact on the Hubble Tension

Behnam Pourhassan, İzzet Sakallı, Sudhaker Upadhyay +1

The Hubble tension (HT) represents one of the most significant discrepancies in modern cosmology, with local distance measurements yielding km/s/Mpc while cosm…

gr-qc2026

Perturbative and Non-Perturbative Contributions to Black Hole Thermodynamics with String Clouds and Dark Matter Backgrounds

Kumar Sambhav Upadhyay, Sudhaker Upadhyay, Bhabani Prasad Mandal

We investigate the effects of perturbative and non-perturbative quantum corrections on the thermodynamics of black holes immersed in a perfect fluid dark matter (PFDM) background w…

gr-qc2026

Extended thermodynamics and Criticality of Kalb-Ramond black hole coupled with nonlinear electrodynamics

D. V. Singh, S. Upadhyay, P. Paul +1

We present an exact black hole solution in anti-de Sitter (AdS) spacetime with a Kalb-Ramond field coupled to nonlinear electrodynamics (NLED), characterized by mass, magnetic mono…

gr-qc2026

Thermodynamics, Shadow, and Quasinormal Modes of AdS Ayón--Beato--García Massive Black Hole

Dharm Veer Singh, Sudhaker Upadhyay, Amit Kumar +3

We investigate the thermodynamics, photon sphere, and dynamical stability of an AdS Ayón--Beato--García (ABG) massive black hole with graviton mass and magnetic charge. The Gibbs…

gr-qc2026

More Exact Thermodynamic Analysis of Topological Black Holes in Gravity

Sudhaker Upadhyay, Jyotish Kumar, Dharm Veer Singh +3

This study investigates the thermodynamics of topological black hole solutions in gravity, incorporating the effects of small statistical fluctuations up to first-order cor…

hep-th2025

Holography and the Swampland: Constraints on Quantum Gravity from Holographic Principles

Sudhaker Upadhyay, Alexander Reshetnyak, Pavel Moshin +1

The Swampland Program aims to delineate the space of consistent low-energy effective field theories (EFTs) that admit a UV completion in quantum gravity from those that do not. In…