arXiv subjects

Ashes Modak

Publications and source records attributed to Ashes Modak.

3 recordsLinked to original sources

arXiv2026

Electromagnetic response of a relativistic drifting plasma

We investigate the charge transport properties of a relativistic drifting plasma using the kinetic theory within the relaxation time approximation. The collective drift induced by electromagnetic fields is described in terms of a suitably modified distribution function. The analysis is done for both constant and time dependent field configurations. For constant electromagnetic fields, we obtain the Hall drift current that arises from the transverse motion of charged particles in electric and magnetic fields. Extending the framework to time dependent electric fields, we show that their temporal variations give rise to polarization drift, which significantly alters the structure of the induced current and introduces additional components along both the conventional drift and polarization directions. We present a quantitative estimate of the Hall drift and polarization induced contributions in the quark gluon plasma and study the temperature dependence of the associated charge transport coefficients in the QCD.

hep-ph↗

arXiv2025

A Note on Chaos in Hayward Black Holes with String Fluids

In this work, we first examine the onset of thermodynamic chaos in Hayward AdS black holes with string fluids, emphasizing the effects of temporal and spatially periodic perturbations. We apply Melnikov's approach to examine the perturbed Hamiltonian dynamics and detect the onset of chaotic behavior. In the case of temporal perturbations induced by thermal quenches, chaos occurs for perturbation amplitude $\gamma$ exceeding a critical threshold, determined by charge $q$ and the string fluid parameter. From the equation of state of the black hole, a general condition is established indicating that under temporal perturbations, the existence of charge is an essential prerequisite for chaos. However, regardless of the presence of charge, spatial perturbations result in chaotic behavior. Further next, we compute the Lyapunov exponent associated with the thermodynamic system to further quantify chaotic behavior beyond the threshold condition. We demonstrate that the string fluid density and the Hayward regularization parameter have a considerable effect on the amplitude of the Lyapunov exponent, showing the control of thermal instability by regular geometry corrections and matter sources. These results highlight the rich nonlinear dynamics arising from the interplay of geometric regularization, matter content, and phase-space instability.

gr-qc↗

arXiv2025

Logarithmic Corrections for Near-extremal Kerr-Newman Black Holes

In this paper, we have computed the logarithmic corrections of entropy for the near-extremal Kerr-Newman black holes in $\mathcal{N}=2$ supergravity theory applying the Euclidean path integral approach in the near-horizon geometry. In the near-horizon extremal Kerr geometry, analogous to the $AdS_{2} \times S^2 $ structure, there exists a set of normalizable zero modes associated with reparametrizations of boundary time. The one-loop approximation to the Euclidean near-horizon extremal Kerr partition function exhibits an infrared divergence due to the path integral over these zero modes. Carrying out the leading finite temperature correction in the near-horizon extremal Kerr scaling limit, we control this divergence. Considering the near-extremal near-horizon geometry as a perturbation around the extremal near-horizon geometry, we determine these corrections implementing a modified heat kernel approach which involves both the extremal and near-extremal corrections and is novel in the literature for the charged rotating black holes in supergravity theory. This result should be reproduced by any microscopic theory that explains the entropy of the black hole.

hep-th↗