arXiv subjects

Dilip Kumar

Publications and source records attributed to Dilip Kumar.

13 recordsLinked to original sources

arXiv2025

Effect of Noncommutative Geometry on Accretion Disks around RGI-Schwarzschild Black Hole

In this study, we explore the combined effects of quantum gravity induced by non-commutativity and scale-dependent gravitational coupling on the thermal properties of the thin accretion disks around a Schwarzschild black hole. We consider a $\kappa$-deformed Renormalization Group Improved (RGI) Schwarzschild black hole, where the classical Schwarzschild black hole geometry is modified by the $\kappa$-deformation of space-time and the running Newton's coupling constant $G(r)$. Using the modified metric, we derive the geodesic motion of massive particles, the effective potential, and the thermal properties such as the radiated energy flux, luminosity, and the temperature profile of the accretion disk around the $\kappa$-deformed RGI-Schwarzschild black hole. Our study shows that when non-commutativity is combined with the RGI framework, the effects produce a noticeable deviation from the classical Schwarzschild case. In particular, for small values of the deformation parameter, we observe an increase in the peak energy flux and the temperature of the accretion disk. This suggests that quantum gravity corrections enhance the disk's radiative efficiency, especially in the inner regions closer to the black hole.

gr-qc↗

arXiv2025

Gamma Ray Bursts from Magnetic Reconnection in Cosmic Strings Wakes

Magnetic reconnection in magnetized wakes of cosmic strings results in the release of a large amount of energy. This energy is released in a short period of time. In this work, we show that this sudden release of energy can result in a Gamma Ray Burst (GRB) of short duration. The magnetic reconnection occurs at several points of the cosmic string wake. The emerging shocks from these points have different velocities. These shocks will collide with each other and give rise to short bursts of energy. The emitted pulse of energy depends on the background magnetic field and the timescale associated with the magnetic reconnection in the cosmic string wake. We also obtain the synthetic lightcurve that occurs from multiple collisions of the shock waves that are emitted from the multiple points of magnetic reconnection in the wake region. Finally, we fit the current experimental data of short GRB which are in the same energy range as the ones predicted from our model.

astro-ph.CO↗

arXiv2024

Magnetic field amplification and decay in cosmic string wakes

We do a detailed study on vortex formation in a magnetized plasma within the spacetime of a moving cosmic string using analytical and numerical methods. The conical spacetime around the cosmic string causes the frozen-in magnetic field to deform due to the fluid flow. We find that the overdensity in the wake region amplifies the magnetic field. This amplification depends on the direction and the lengthscale of the magnetic perturbations. Alfvens theorem of flux conservation explains this result. However, our study also shows that the magnetic field can decay depending on the perturbation lengthscale, due to the breakdown of Alfvens theorem at a certain lengthscale. This lengthscale is the gyroradius of the charged particles in the plasma. Our findings are significant for understanding magnetic reconnection in cosmic string wakes.

astro-ph.CO↗

arXiv2024

Fox's H-Functions: A Gentle Introduction Through Astrophysical Thermonuclear Functions

Needed for cosmological and stellar nucleosynthesis, we are studying the closed-form analytic evaluation of thermonuclear reaction rates. In this context, we undertake a comprehensive analysis of three distinct velocity distributions, namely the Maxwell-Boltzmann distribution, the pathway distribution, and the Mittag-Leffer distribution. We emphasize the utilization of Meijer G-function and Fox H-function which are special functions of mathematical physics.

nucl-th↗

arXiv2024

Geodesic motion of particles in the vicinity of the $\kappa$-deformed Schwarzchild Black Hole

In this study, we investigate the geodesic motion of a test particle around the Schwarzchild black hole in a $\kappa$-deformed space-time. We compute a modified Lagrangian to obtain the $\kappa$-deformed effective potential and find the particle trajectories based on the constants of motion. For the same value of angular momentum, we obtain a significant deformation in the orbits of the particles due to the non-commutativity of the $\kappa$-deformed space-time. The deformation parameter becomes more significant for higher values of the angular momentum. The radius of the individual trajectories become smaller and their velocities decrease compared to the commutative case. The radius of the innermost stable circular orbit ($r_{ISCO}$) is also found using the modified effective potential. Though the equations get modified due to the non-commutativity of the $\kappa$-deformed space-time, the $r_{ISCO}$ remains the same. We then study a large number of freely streaming particles moving in this $\kappa$-deformed space-time and analyze the movement of these particles around the black hole due to the non-commutativity of the space-time. We concentrate on particles with different angular momentum moving around the black hole. We find that the motion of the particles are modified due to the non-commutativity of the space-time. The particles move slower along their respective trajectories in the deformed space-time. So, they remain closer to the black hole for a longer period of time, indicating that the accretion of freely streaming particles around the black hole would be modified by the non-commutativity of the space-time.

gr-qc↗

arXiv2024

algoXSSF: Detection and analysis of cross-site request forgery (XSRF) and cross-site scripting (XSS) attacks via Machine learning algorithms

The global rise of online users and online devices has ultimately given rise to the global internet population apart from several cybercrimes and cyberattacks. The combination of emerging new technology and powerful algorithms (of Artificial Intelligence, Deep Learning, and Machine Learning) is needed to counter defense web security including attacks on several search engines and websites. The unprecedented increase rate of cybercrime and website attacks urged for new technology consideration to protect data and information online. There have been recent and continuous cyberattacks on websites, web domains with ongoing data breaches including - GitHub account hack, data leaks on Twitter, malware in WordPress plugins, vulnerability in Tomcat server to name just a few. We have investigated with an in-depth study apart from the detection and analysis of two major cyberattacks (although there are many more types): cross-site request forgery (XSRF) and cross-site scripting (XSS) attacks. The easy identification of cyber trends and patterns with continuous improvement is possible within the edge of machine learning and AI algorithms. The use of machine learning algorithms would be extremely helpful to counter (apart from detection) the XSRF and XSS attacks. We have developed the algorithm and cyber defense framework - algoXSSF with machine learning algorithms embedded to combat malicious attacks (including Man-in-the-Middle attacks) on websites for detection and analysis.

cs.CR↗

arXiv2023

Synchrotron radiation from cosmic string wakes

Magnetic fields can be generated in cosmic string wakes due to the Biermann mechanism in the presence of neutrino inhomogeneities. As the cosmic string moves through the plasma the small magnetic field is amplified by the turbulence in the plasma. Relativistic charged particles which cross the magnetized wake of a cosmic string will therefore emit synchrotron radiation. The opening angle of the cosmic string is very small and so the wake appears like a relativistic jet. Assuming a homogeneous magnetic field in the wake of the string, we obtain the synchrotron emission from non thermal relativistic electrons in the wake of the string. The emitted radiation has a broad peak and is over a wide range of frequency. We show that the spectrum can be mapped to some of the unknown sources in different ranges of the current available catalogues.

astro-ph.CO↗

arXiv2023

SugarChain: Blockchain technology meets Agriculture -- The case study and analysis of the Indian sugarcane farming

Not only in our country and Asia, but the agriculture sector is also lagging all over the world while using new technologies and innovations. Farmers are not getting the accurate price and compensation of their products because of several reasons. The intermediate persons or say middlemen are controlling the prices and product delivery on their own. Due to lack of education, technological advancement, market knowledge, post-harvesting processes, and middleman involvement, farmers are always deprived of their actual pay and efforts. The use of blockchain technology can help such farmers to automate the process with high trust. We have presented our case study and analysis for the Indian sugarcane farming with data collected from farmers. The system implementation, testing, and result analysis has been shown based on the case study. The overall purpose of our research is to emphasize and motivate the agricultural products and benefit the farmers with the use of blockchain technology.

cs.CY↗

arXiv2022

Magnetic reconnection in the wakes of cosmic strings

The motion of cosmic strings in the universe leads to the generation of wakes behind them. We study magnetized wakes of cosmic strings moving in the post recombination plasma. We show that magnetic reconnection can occur in the post shock region. Since the width of the cosmic string wake is very small, the reconnection occurs over a very short lengthscale. The reconnection leads to a large amount of kinetic energy being released in the post shock region of the cosmic string wake. This enhances the kinetic energy released during the reconnection. We make a rudimentary estimate of the kinetic energy released by the magnetic reconnection in cosmic strings wakes and show that it can account for low energy Gamma Ray Bursts (GRB) in the post recombination era.

astro-ph.CO↗

arXiv2015

Efficient Hardware Design and Implementation of Encrypted MIPS Processor

The paper describes the design and hardware implementation of 32-bit encrypted MIPS processor based on MIPS pipeline architecture. The organization of pipeline stages in such a way that pipeline can be clocked at high frequency. Encryption and Decryption blocks of data encryption standard (DES) cryptosystem and dependency among themselves are explained in detail with the help of block diagram. In order to increase the processor functionality and performance, especially for security applications we include three new instructions 32-bit LKLW, LKUW and CRYPT. The design has been synthesized at 40nm process technology targeting using Xilinx Virtex-6 device. The encrypted MIPS pipeline processor can work at 218MHz at synthesis level and 744MHz at simulation level.

cs.CR↗

arXiv2014

Distributed Transformer Monitoring System Based On Zigbee Technology

A Distributed transformer networks remote monitoring system is developed and constructed,for monitor and record the parameters like temperature, oil level status, of a distribution transformer.The system consists of a micro controller based circuit,with solid-state components for handling sensors,power back-up,real time clock and data communication module which based on ZigBee protocol.

cs.OH↗

arXiv2013

Performance Evaluation of Low Power MIPS Crypto Processor based on Cryptography Algorithms

This paper presents the design and implementation of low power 32-bit encrypted and decrypted MIPS processor for Data Encryption Standard (DES), Triple DES, Advanced Encryption Standard (AES) based on MIPS pipeline architecture. The organization of pipeline stages has been done in such a way that pipeline can be clocked at high frequency. Encryption and Decryption blocks of three standard cryptography algorithms on MIPS processor and dependency among themselves are explained in detail with the help of a block diagram. Clock gating technique is used to reduce the power consumption in MIPS crypto processor. This approach results in processor that meets power consumption and performance specification for security applications. Proposed Implementation approach concludes higher system performance while reducing operating power consumption. Testing results shows that the MIPS crypto processor operates successfully at a working frequency of 218MHz and a bandwidth of 664Mbits/s.

cs.CR↗

arXiv2012

Wishbone bus Architecture - A Survey and Comparison

The performance of an on-chip interconnection architecture used for communication between IP cores depends on the efficiency of its bus architecture. Any bus architecture having advantages of faster bus clock speed, extra data transfer cycle, improved bus width and throughput is highly desirable for a low cost, reduced time-to-market and efficient System-on-Chip (SoC). This paper presents a survey of WISHBONE bus architecture and its comparison with three other on-chip bus architectures viz. Advanced Micro controller Bus Architecture (AMBA) by ARM, CoreConnect by IBM and Avalon by Altera. The WISHBONE Bus Architecture by Silicore Corporation appears to be gaining an upper edge over the other three bus architecture types because of its special performance parameters like the use of flexible arbitration scheme and additional data transfer cycle (Read-Modify-Write cycle). Moreover, its IP Cores are available free for use requiring neither any registration nor any agreement or license.

cs.AR↗