arXiv subjects

Naveed Ahmad Shah

Publications and source records attributed to Naveed Ahmad Shah.

9 recordsLinked to original sources

arXiv2025

Holographic Consequences of Heterotic String Theory beyond its Supergravity Approximation

In this work, we study the effects of stringy corrections on the low energy effective action derived from heterotic string theory beyond its supergravity approximation. Compactifying the ten dimensional theory with these stringy corrections produces an effective action for a scalar field whose higher derivative term is governed by a single coefficient that depends on the internal volume, average curvature, and flux of the compactification manifold. The higher derivative coupling imported from compactification shifts the Breitenlohner Freedman stability bound by an amount set by the relative strengths of internal flux and curvature, relaxing it in flux dominated vacua and tightening it in curvature dominated ones. Furthermore, we analyze how the stringy corrections shift the scaling dimensions of the dual operators, track the resulting renormalization group flow, and investigate the higher derivative term using a holographic Lee Wick regulator. In holographic superconductors, stringy corrections lower the effective bulk mass and raise the critical temperature when flux dominates, but have the opposite effect when curvature dominates.

hep-th↗

arXiv2025

Derivation of the deformed Heisenberg algebra from discrete spacetime

Although the deformation of the Heisenberg algebra by a minimal length has become a central tool in quantum gravity phenomenology, it has never been rigorously obtained and is often derived using heuristic reasoning. In this study, we move beyond the heuristic derivation of the deformed Heisenberg algebra and explicitly derive it using a model of discrete spacetime, which is motivated by quantum gravity. Initially, we investigate the effects of the leading order Planckian lattice corrections and demonstrate that they precisely match those suggested by the heuristic arguments commonly used in quantum gravity phenomenology. Furthermore, we rigorously obtain deformations from the higher-order Planckian lattice corrections. In contrast to the leading-order corrections, these higher-order corrections are model dependent. We select a specific model that breaks the rotational symmetry, as the importance of such rotational symmetry breaking lies in the relationship between CMB anisotropies and quantum gravitational effects. Based on the mathematical similarity of the Planckian lattice used here with the graphene lattice, we propose that graphene can serve as an analogue system for the study of quantum gravity. Finally, we examine the deformation of the covariant form of the Heisenberg algebra using a four-dimensional Euclidean lattice.

gr-qc↗

arXiv2025

Information Theoretical Approach to Detecting Quantum Gravitational Corrections

One way to test quantum gravitational corrections is through black hole physics. In this paper, We investigate the scales at which quantum gravitational corrections can be detected in a black hole using information theory. This is done by calculating the Kullback-Leibler divergence for the probability distributions obtained from the Parikh-Wilczek formalism. We observe that the quantum gravitational corrections increase the Kullback-Leibler divergence as the mass of the black hole decreases, which is expected as quantum gravitational corrections can be neglected for larger black holes. However, we further observe that after a certain critical value, quantum gravitational corrections tend to decrease again as the mass of the black hole decreases. To understand the reason behind this behavior, we explicitly obtain Fisher information about such quantum gravitational corrections and find that it also increases as the mass decreases, but again, after a critical value, it decreases. This is because at such a scale, quantum fluctuations dominate the system and we lose information about the system. We obtain these results for higher-dimensional black holes and observe this behavior for Kullback-Leibler divergence and Fisher information depending on the dimensions of the black hole. These results can quantify the scale dependence and dimension dependence of the difficulty in detecting quantum gravitational corrections.

hep-th↗

arXiv2024

Quantization of Yang-Mills Theory in de Sitter Spacetime

In this paper, we analyze the quantization of Yang-Mills theory in the de Sitter spacetime. It is observed that the Faddeev--Popov ghost propagator is divergent in this spacetime. However, this divergence is removed by using an effective propagator, which is suitable for perturbation theory. To show that the quantization of Yang--Mills theory in the de Sitter is consistent, we quantize it using first-class constraints in the temporal gauge. We also demonstrate that this is equivalent to quantizing the theory in the Lorentz gauge.

hep-th↗

arXiv2024

Effective information bounds in modified quantum mechanics

A common feature of collapse models and an expected signature of the quantization of gravity at energies well below the Planck scale is the deviation from ordinary quantum-mechanical behavior. Here, we analyze the general consequences of such modifications from the point of view of quantum information theory and we anticipate applications to different quantum systems. We show that quantum systems undergo corrections to the quantum speed limit which, in turn, imply the modification of the Heisenberg limit for parameter estimation. Our results hold for a wide class of scenarios beyond ordinary quantum mechanics. For some nonlocal models inspired by quantum gravity, the bounds are found to oscillate in time, an effect that could be tested in future high-precision quantum experiments.

quant-ph↗

arXiv2023

Deformation of Nanowires and Nanotubes

In this article, we have investigated the consequences of the next to the leading order correction to the effective field theory of nanostructures. This has been done by analyzing the effects of deformed Heisenberg algebra on nanowires and nanotubes. We first deform the Schrodinger equation with cylindrical topology. Then specific solutions to the deformed Schrodinger equation with different boundary conditions are studied. These deformed solutions are used to investigate the consequences of the deformation on the energy of nanowires and nanotubes.

cond-mat.mes-hall↗

arXiv2022

Causality in String Field Theory

In this letter, we will investigate causality in string field theory using pp-wave light-cone gauge string field theory. We will generalize the Ramsey scheme to string field theory, and use it to analyze string field theoretical processes. An explicit characteristic function for interactive string field theory will be built using this string field theoretical Ramsey scheme. The average of the difference between the initial and final values of any operator described in string field theory will be obtained using this characteristic function. We will use the quantum information theoretical technique based on quantum fisher information to extract information about such string field theoretical processes.

hep-th↗

arXiv2021

Effects of discrete topology on quantum transport across a graphene $n-p-n$ junction: A quantum gravity analogue

In this article, we investigate the effect of next-to-the-nearest atom hopping on Klein tunnelling in graphene. An effective quantum dynamics equation is obtained based on an emergent generalized Dirac structure by analyzing the tight-binding model beyond the linear regime. We show that this structure has some interesting theoretical properties. First, it can be used to simplify quantum transport calculations used to characterize Klein tunnelling; second, it is not Chirally symmetric as hinted by previous work. Finally, it is reminiscent of theories on a space with a discrete topology. Exploiting these properties, we show that the discrete topology of the crystal lattice has an effect on the Klein tunnelling, which can be experimentally probed by measuring the transmittance through $n-p-n$ junctions. We argue that this simulates quantum gravitational analogues using graphene and we propose an experiment to perform such measurements.

cond-mat.mes-hall↗

arXiv2017

Quantum Eraser for Three-Slit Interference

It is well known that in a two-slit interference experiment, if the information, on which of the two paths the particle followed, is stored in a quantum path detector, the interference is destroyed. However, in a setup where this path information is "erased", the interference can reappear. Such a setup is known as a quantum eraser. A generalization of quantum eraser to a three-slit interference is theoretically analyzed. It is shown that three complementary interference patterns can arise out of the quantum erasing process.

quant-ph↗