collaborators

6 papers

gr-qc2026

New Universal Relations for Magnetized Neutron Stars

Byon N. Jayawiguna, Siddarth Ajith, Takuya Katagiri +2

Unlike the neutron-star mass--radius relation, which depends sensitively on the internal stellar structure through the equation of state of dense nuclear matter, certain neutron-st…

hep-th2026

Higher-Derivative Corrections to Reissner--Nordström Black Holes from Worldline QFT

Siddarth Ajith, Ravisankar Rajagopal, Nur Rifat +2

In this paper we derived the corrections to the Reissner-Nordström black hole when higher-derivative terms (contractions of the Riemann tensor with the Maxwell field strengt…

astro-ph.HE2026

Gravitational-Wave Constraints on Neutron-Star Pressure Anisotropy via Universal Relations

Victor Guedes, Siddarth Ajith, Shu Yan Lau +1

Neutron stars may exhibit pressure anisotropy arising from various physical mechanisms, such as elasticity, magnetic fields, viscosity, and superfluidity. We compute the tidal defo…

gr-qc2026

Spacetime Quasi-normal Mode Oscillations of Anisotropic Neutron Stars

Jihao Yu, Victor Guedes, Shu Yan Lau +2

Neutron star asteroseismology offers a unique opportunity to probe nuclear physics through stellar oscillations. Although the pressure inside of a neutron star is typically assumed…

hep-th2025

Worldline Formalism, Eikonal Expansion and the Classical Limit of Scattering Amplitudes

Siddarth Ajith, Yuchen Du, Ravisankar Rajagopal +1

We revisit the fundamentals of two different methods for calculating classical observables: the eikonal method, which is a scattering amplitude-based method, and the worldline quan…

hep-th2025

Worldline Proof of Eikonal Exponentiation

Yuchen Du, Siddarth Ajith, Ravisankar Rajagopal +1

In this paper, working in the eikonal approximation, we present a proof for the exponentiation of the 2-body eikonal phase to {\it all orders in the eikonal expansion}, for scalar…