arXiv subjects

Subhra Mondal

Publications and source records attributed to Subhra Mondal.

4 recordsLinked to original sources

arXiv2026

Resolution of Infrared Entanglement Divergences via the Extended Uncertainty Principle

The entanglement entropy of quantum systems typically exhibits both ultraviolet and infrared (IR) divergences. In the low-frequency limit, the IR divergence is intimately tied to the unbounded spatial delocalization of zero-modes, a pathological feature common to both coupled harmonic oscillators and massless scalar fields. In this work, we demonstrate that this infinite growth is naturally resolved by invoking the Extended Uncertainty Principle (EUP), which introduces large-length-scale geometric corrections to the canonical commutation relations. By exactly solving the simple harmonic oscillator under the EUP framework, we establish the existence of an intrinsic geometric confinement that enforces a strict upper bound on the position variance, limits spatial delocalization, and introduces an intrinsic localization length scale related to the background Ricci scalar. We extend this regularizing mechanism to many-body systems by evaluating the entanglement entropy and entanglement spectrum of a one-dimensional harmonic chain and a massless scalar field. We show that the EUP-induced spatial bounds prevent the accumulation of low-lying long-wavelength modes, keeping the entanglement spectrum discrete and evenly gapped even in the strictly massless limit. This non-vanishing modular gap effectively caps the local entanglement temperature of the vacuum. Consequently, the entanglement entropy saturates to a finite value, providing a robust, geometric resolution to the zero-mode IR divergence problem in quantum field theory.

gr-qc↗

arXiv2026

Gravity theory of the generalized mass to horizon entropy The Iyer Wald approach

In this letter, our aim is to study the gravitational origin of the \textit{generalized mass-to-horizon entropy} (GMHE), described by an entropic exponent index $n$ and a multiplicative parameter $\gamma$. We employ Iyer-Wald's approach within the modified $\mathfrak{f(R)}$ gravity scenario in order to assess the horizon entropy of the black hole (BH) by considering solutions with constant curvature for the spherically symmetric vacuum field equations. In this process, we explicitly show that the GMHE can effectively be reconstructed from a generalized Lagrangian $\mathfrak{L}\propto \mathfrak{R}^{1+\epsilon}$, where $\epsilon\equiv\frac{n-1}{2}$ measures tiny departures from the standard formulation of general relativity (GR). Finally, we discuss the physical implications of our results in relation to cosmology and the prospects for alleviating the thermodynamic instability of Schwarzschild BHs.

gr-qc↗

arXiv2026

Cosmological dynamics and structure formation in a generalized mass-to-horizon entropy-inspired modified gravity

In this article, our goal is to investigate the cosmological dynamics and structure formation in a modified cosmological framework inspired by a generalized mass-to-horizon entropy relation and consistent with the Clausius relation. Invoking the gravity-thermodynamics conjecture leads to alterations in the Friedmann equations as well as Hubble parameter evolution. The effects of the generalized entropy on various cosmographic parameters and on the growth of the linear matter perturbations by constructing perturbed field equations via employing spherical collapse formalism in a flat Friedmann-Lema\^{i}tre-Robertson-Walker background have been explored. We discuss a novel and well-known diagnostic approach to differentiate various cosmological models vis-\`a-vis flat and non-flat $\Lambda$CDM frameworks, and find that the generalized mass-to-horizon entropy-inspired modified cosmology ($n\ne 1$) successfully passes all the litmus tests by falsifying both the flat and non-flat $\Lambda$CDM paradigms. It is shown that this model also satisfies the requirements for the Universe to achieve thermodynamic equilibrium in the distant future. We also study the halo mass function and cluster number counts in this modified gravity scenario. All the results are compared with the fiducial $\Lambda$CDM profile, showing that the additional entropic correction influences the expansion history, the growth rate of structures, and the abundance of collapsed halos. We observe that the more massive collapsed structures are less abundant and form at later epochs, which is expected from the hierarchical model of large-scale structure formation.}

gr-qc↗

arXiv2013

On the symmetries of the modified Emden-type equation

For an autonomous system the symmetries of the Lagrangian are embedded in the symmetries of the differential equation. Recently, it has been found that the modified Emden-type equations follow from non-standard Lagrangian functions which involve neither the kinetic energy term nor the potential function. By working with one such Lagrangian we have calculated the Lagrangian symmetries and explicitly demonstrated that, as in the case of standard Lagrangian functions, the variational symmetries of the non-standard Lagrangian are also included in the Lie symmetries of the differential equation.

nlin.SI↗