arXiv subjects

Anil Kumar

Publications and source records attributed to Anil Kumar.

At least 37 records · Page 2Linked to original sources

arXiv2026

First Constraints on Long-Range Neutrino Interactions using IceCube DeepCore

We present the first search for new flavor-dependent long-range interactions (LRI) of neutrinos using publicly available 8 years of high-purity $ν_μ$ CC data from IceCube DeepCore. These interactions are mediated by ultra-light gauge bosons with masses below $10^{-10}$ eV, which can arise due to a new lepton-number gauge symmetry, such as $L_e - L_μ$ or $L_e - L_τ$. These long-range interactions induce matter potential between neutrinos and abundant electrons present in distant astrophysical sources. These LRI potentials could modify neutrino oscillation probabilities. By probing the effects of LRI on atmospheric neutrino oscillations at IceCube DeepCore, we place world-leading constraints on the coupling strength of these interactions.

hep-ph↗

arXiv2025

Modulation of quantum geometry and its coupling to pseudo-electric field by dynamic strain

Two-dimensional materials are a fertile ground for exploring quantum geometric phenomena, with Berry curvature and its first moment, the Berry curvature dipole, playing a central role in their electronic response. These geometric properties influence electronic transport and result in the anomalous and nonlinear Hall effects, and are typically controlled using static electric fields or strain. However, the possibility of modulating quantum geometric quantities in real-time remains unexplored. Here, we demonstrate the dynamic modulation of Berry curvature and its moments, as well as the generation of a pseudo-electric field using time-dependent strain. By placing heterostructures on a membrane, we introduce oscillatory strain together with an in-plane AC electric field and measure Hall signals that are modulated at linear combinations of the frequencies of strain and electric field. Our measurements reveal modulation of Berry curvature and its first moment. Notably, we provide direct experimental evidence of pseudo-electric field that results in an unusual dynamic strain-induced Hall response. This approach opens up a new pathway for controlling quantum geometry on demand, moving beyond conventional static perturbations. The pseudo-electric field provides a framework for external electric field-free anomalous Hall response and opens new avenues for probing the topological properties.

cond-mat.mes-hall↗

arXiv2025

Stringent constraints on non-standard neutrino interactions using high-purity $ν_μ$ CC events in IceCube DeepCore

The neutral-current (NC) non-standard interactions (NSI) of neutrinos with fermions can modify the flavor oscillations of atmospheric neutrinos as they propagate through the Earth. We present constraints on the NC-NSI parameters $\varepsilon_{μτ}$ and $\varepsilon_{ττ}-\varepsilon_{μμ}$ (one at a time) using a high-purity sample of $ν_μ$ charged-current (CC) atmospheric neutrino events collected by IceCube DeepCore over 7.5 years of livetime. These two parameters significantly affect the $ν_μ$ disappearance channel for which this golden event sample is optimized by the IceCube Collaboration. The best fit to this dataset is consistent with no NSI hypothesis, and we place the most stringent constraints to date: $-\,0.0094 < \varepsilon_{μτ} < 0.0079$ and $-\,0.030 < \varepsilon_{ττ}-\varepsilon_{μμ} < 0.029$ at 90% confidence level.

hep-ph↗

arXiv2025

Real-Time Cooked Food Image Synthesis and Visual Cooking Progress Monitoring on Edge Devices

Synthesizing realistic cooked food images from raw inputs on edge devices is a challenging generative task, requiring models to capture complex changes in texture, color and structure during cooking. Existing image-to-image generation methods often produce unrealistic results or are too resource-intensive for edge deployment. We introduce the first oven-based cooking-progression dataset with chef-annotated doneness levels and propose an edge-efficient recipe and cooking state guided generator that synthesizes realistic food images conditioned on raw food image. This formulation enables user-preferred visual targets rather than fixed presets. To ensure temporal consistency and culinary plausibility, we introduce a domain-specific \textit{Culinary Image Similarity (CIS)} metric, which serves both as a training loss and a progress-monitoring signal. Our model outperforms existing baselines with significant reductions in FID scores (30\% improvement on our dataset; 60\% on public datasets)

cs.CV↗

arXiv2025

Error analysis with exponential decay estimates for a fully discrete approximation of a class of strongly damped wave equations

This paper deals with the asymptotic behavior and FEM error analysis of a class of strongly damped wave equations using a semidiscrete finite element method in spatial directions combined with a finite difference scheme in the time variable. For the continuous problem under weakly and strongly damping parameters $α$ and $β,$ respectively, a novel approach usually used for linear parabolic problems is employed to derive an exponential decay property with explicit rates, which depend on model parameters and the principal eigenvalue of the associated linear elliptic operator for the different cases of parameters such as $(i) \;α, β>0$, $ (ii)\; α>0, β\geq 0$ and $(iii)\;α\geq 0, β>0$. Subsequently, for a semi-discrete finite element scheme keeping the temporal variable continuous, optimal error estimates are derived that preserve exponential decay behavior. Some generalizations that include forcing terms and spatially as well as time-varying damping parameters are discussed. Moreover, an abstract discrete problem is discussed, and as a consequence, uniform decay estimates for finite difference as well as spectral approximations to the damped system are briefly indicated. A complete discrete scheme is developed and analyzed after applying a finite difference scheme in time, which again preserves the exponential decay property. The given proofs involve several energies with energy-based techniques to derive the consistency between continuous and discrete decay rates, in which the constants involved do not blow up as $α\to 0$ and $β\to 0$. Finally, several numerical experiments are conducted whose results support the theoretical findings, illustrate uniform decay rates, and explore the effects of parameters on stability and accuracy.

math.NA↗

arXiv2025

Probing the shape evolution and shell structures in neutron-rich N=50 nuclei

The structure of low-lying states of $N=50$ nuclei is investigated by the advanced Monte Carlo shell model (MCSM) in the $π{(fp)}$-$ν{(sdg)}$ model space. We have employed the shell-model Hamiltonian based on the valence-space in-medium similarity renormalization group, with minimal phenomenological adjustments to the single-particle energies. The MCSM results with the modified Hamiltonian nicely predict the shape coexistence of $^{78}$Ni, consistent with recent experimental data. The evolution of intrinsic shapes from the spherical shape to prolate shapes in the ground state of $N=50$ nuclei is discussed using the "T-plot" and effective single-particle energies, which visualize the intrinsic quadrupole deformation of the MCSM wave function. The present result shows that the monopole part of the tensor force does not enhance the shape coexistence of $^{78}$Ni, unlike the case of $^{68}$Ni.

nucl-th↗

arXiv2025

Probing Earth's core using atmospheric neutrino oscillations in the presence of NSI at INO-ICAL

Neutrinos can serve as a complementary and independent tool to gravitational and seismic studies in exploring the interior of Earth, thanks to their unique properties: extremely low interaction cross sections and flavor oscillations. With the precise measurements of neutrino oscillation parameters and observation of the non-zero value of mixing angle $θ_{13}$, it has become feasible to detect the forward scattering of GeV-energy atmospheric neutrinos passing through Earth with ambient electrons in the form of matter effects on neutrino oscillation probabilities. These matter effects depend on both the neutrino energy and electron density distribution along their path, making them ideally suited for exploring the inner structure of Earth. Furthermore, in the presence of non-standard interactions (NSI) of neutrinos with matter, oscillation patterns undergo additional modifications. In this study, we quantify the capability of an atmospheric neutrino experiment, such as a magnetized iron calorimeter detector, to validate the Earth's core and measure the position of the core-mantle boundary in the presence of NSI. We perform this study considering a three-layered density profile of Earth. Our analysis demonstrates that neutrino non-standard interactions impact these Earth tomography measurements in comparison to standard interactions.

hep-ph↗

arXiv2025

Studies on Response Uniformity of RPC and Exploring Oscillation Dip and Valley, Non-Standard Interactions, and Earth's Core using Atmospheric Neutrinos at ICAL-INO detector

In this thesis, experimental and physics simulation studies are performed in the context of the proposed 50 kt Iron Calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO). ICAL would detect atmospheric muon neutrinos and antineutrinos separately in the multi-GeV range of energies over a wide range of baselines. In the experimental part of the thesis, the effect of the non-uniformity of the graphite layer on the detector response of the resistive plate chamber is studied. In the physics simulation part, it is demonstrated for the first time that the neutrino oscillation dip and valley can be observed at ICAL using the up/down ratio of reconstructed muons and antimuons separately. A method is formulated such that the location of the dip and the alignment of the valley can be used to measure an atmospheric oscillation parameter called the mass-squared difference. Further, a new approach is proposed to probe the neutral-current non-standard interactions (NSIs) using the oscillation dip and valley. The opposite shifts in the oscillation dips and the contrast in the curvatures of oscillation valleys for reconstructed muons and antimuons are used to constrain the NSI parameter in two separate ways. While passing through the Earth, the upward-going atmospheric neutrinos experience the matter effects, which modify the neutrino oscillation patterns. These matter effects depend upon the density of electrons inside Earth and can be used to perform the neutrino oscillation tomography of Earth, complementary to gravitational measurements and seismic studies. This work demonstrates that the presence of Earth's core can be validated using the atmospheric neutrinos at ICAL.

hep-ph↗

arXiv2025

Imprints of Non-Symmetric Dark Matter Halos on Magnetars: A Two-Fluid Perspective

In this study, we investigate the impact of dark matter on the structure and deformation of magnetars. We assume a perturbative approach for the magnetic field deformation and that the dark matter only interacts gravitationally with hadronic matter. Assuming that dark matter is significantly softer than hadronic matter, we find that the magnetic field can affect dark matter through the deformation of space-time. The number of stars having a dark matter halo outside the visible surface of the star increases with an increase in dark matter fraction and the stiffness of the dark matter equation of state. As the magnetic field deforms the stars from sphericity, we can have a situation where we have a non-symmetric dark matter halo outside the star. The deformation of the dark matter halo gives rise to the discrepancies in the observed period $P$ (and period derivative $\dot{P}$) and gravitational wave signatures. The observed visible surfaces predict a lower period and gravitational wave strain than that with a dark matter halo. This can have interesting observational gravitational signatures unique to magnetars having a dark matter halo.

astro-ph.HE↗

arXiv2025

CoRuTiGe: A Possible Spin Gapless Semiconductor

We report experimental and theoretical investigations on the quaternary Heusler alloy CoRuTiGe, synthesized using the arc melting technique. Crystal structure analysis reveals a tetragonal structure at room temperature. Magnetization measurements as a function of temperature and magnetic field indicate ferromagnetic nature with a saturation magnetization of 0.681 mB/f.u. at 5 K. The temperature dependence of electrical resistivity shows a nearly linear decrease in the high-temperature range, indicating the spin gapless semiconductor like behavior of the material. This SGS nature is further supported by the temperature-independent carrier concentration and mobility. Hall effect analysis reveals that the anomalous Hall effect in CoRuTiGe arises from both intrinsic and extrinsic mechanisms. Additionally, a well-defined symmetric negative magnetoresistance is observed at low temperatures. These findings suggest that CoRuTiGe holds significant promise for spintronic applications.

cond-mat.mtrl-sci↗

arXiv2025

Investigating Universal Relations in Compact Stars featuring $Δ-$Admixed Exotic Dense Matter

The dense material in a compact star from a supernova remnant is beyond terrestrial experimentation, so phenomenological modeling is used to match astrophysical observations. This is crucial due to the complex sensitivity of compact star features to dense matter properties. Despite modeling flexibility, certain universal relationships among compact star features hold true, regardless of the matter model. Our study examines these universal relationships, focusing on the moment of inertia, tidal Love number, and quadrupole moment, as well as correlations between non-radial oscillation frequencies and star compactness. We consider baryonic stars with cores of heavier baryons. Our findings show that baryonic stars with cores of heavier baryons follow the universal relations, and the f-mode oscillation frequency's universality relative to tidal deformability is notable, with an error margin under 1$\%$.

astro-ph.HE↗

arXiv2025

Robust correlation measures for informative frequency band selection in heavy-tailed vibration signal

Vibration signals are commonly used to detect local damage in rotating machinery. However, raw signals are often noisy, particularly in crusher machines, where the technological process (falling pieces of rock) generates random impulses that complicate detection. To address this, signal pre-filtering (extracting the informative frequency band from noise-affected signals) is necessary. This paper proposes an algorithm for processing vibration signals from a bearing used in an ore crusher. Selecting informative frequency bands (IFBs) in the presence of impulsive noise is notably challenging. The approach employs correlation maps to detect cyclic behavior within specific frequency bands in the time-frequency domain (spectrogram), enabling the identification of IFBs. Robust correlation measures and median filtering are applied to enhance the correlation maps and improve the final IFB selection. Signal segmentation and the use of averaged results for IFB selection are also highlighted. The proposed trimmed and quadrant correlations are compablack with the Pearson and Kendall correlations using simulated signal, real vibration signal from crusher in mining industry and acoustic signal measublack on the test rig. Furthermore, the results of real vibration analyses are compablack with established IFB selectors, including the spectral kurtosis, the alpha selector and the conditional variance-based selector.

eess.SP↗

arXiv2025

Exploring non-radial oscillation modes in dark matter admixed neutron stars

Because of their extreme densities and consequently, gravitational potential, compact objects such as neutron stars can prove to be excellent captors of dark matter particles. Considering purely gravitational interactions between dark and hadronic matter, we construct dark matter admixed stars composed of two-fluid matter subject to current astrophysical constraints of maximum mass and tidal deformability. We choose a wide range of parameters to construct the dark matter equation of state, and the DDME2 parameterization for the hadronic equation of state. We then examine the effect of dark matter on the stellar structure, tidal deformability and non-radial modes considering the relativistic Cowling approximation. We find the effect on p-modes is substantial, with frequencies decreasing up to the typical $f-$mode frequency range for most stars with a dark matter halo. The effects on the f-mode frequency are less extreme. Finally, we find the most probable and $1σ$ values of the dark matter parameters used in this study.

astro-ph.HE↗

arXiv2025

Exploring constraints on the core radius and density jumps inside Earth using atmospheric neutrino oscillations

Atmospheric neutrinos, through their weak interactions, can serve as an independent tool for exploring the internal structure of Earth. The information obtained would be complementary to that provided by seismic and gravitational measurements. The Earth matter effects in neutrino oscillations depend upon the energy of neutrinos and the electron density distribution that they encounter during their journey through Earth, and hence, can be used to probe the inner structure of Earth. In this contribution, we demonstrate how well an atmospheric neutrino experiment, such as an iron calorimeter detector (ICAL), would simultaneously constrain the density jumps inside Earth and determine the location of the core-mantle boundary. In this work, we employ a five-layered density model of Earth, where the layer densities and core radius are modified to explore the parameter space, ensuring that the mass and moment of inertia of Earth remain constant while satisfying the hydrostatic equilibrium condition. We further demonstrate that the charge identification capability of an ICAL-like detector would play a crucial role in obtaining these correlated constraints.

hep-ph↗

arXiv2024

Panel Estimation of Taxable Income Elasticities with Heterogeneity and Endogenous Budget Sets

This paper introduces an estimator for the average of heterogeneous elasticities of taxable income (ETI), addressing key econometric challenges posed by nonlinear budget sets. Building on an isoelastic utility framework, we derive a linear-in-logs taxable income specification that incorporates the entire budget set while allowing for individual-specific ETI and productivity growth. To account for endogenous budget sets, we employ panel data and estimate individual-specific ridge regressions, constructing a debiased average of ridge coefficients to obtain the average ETI.

econ.EM↗

arXiv2024

Focusing of concentric free-surface waves

Gravito-capillary waves at free-surfaces are ubiquitous in several natural and industrial processes involving quiescent liquid pools bounded by cylindrical walls. These waves emanate from the relaxation of initial interface distortions, which often take the form of a cavity (depression) centred on the symmetry axis of the container. These surface waves reflect from the container walls leading to a radially inward propagating wave-train converging (focussing) onto the symmetry axis. Under the inviscid approximation and for sufficiently shallow cavities, the relaxation is well-described by the linearised potential-flow equations. Naturally, adding viscosity to such a system introduces viscous dissipation that enervates energy and dampens the oscillations at the symmetry axis. However, for viscous liquids and deeper cavities, these equations are qualitatively inaccurate. In this study, we elucidate a modal approach to study the initial-value problem for concentric gravito-capillary waves generated on a free-surface for inviscid as well as viscous liquids. For a sufficiently deep cavity, the inward focusing of waves results in large interfacial oscillations at the axis, necessitating a second-order nonlinear theory. We demonstrate that this theory effectively models the interfacial behavior and highlights the crucial role of nonlinearity near the symmetry axis. Contrary to expectations, the addition of slight viscosity further intensifies the oscillations at the symmetry axis. This finding underscores the limitations of the potential flow model and suggests avenues for more accurate modelling of such complex free-surface flows.

physics.flu-dyn↗

arXiv2024

Intelligent fault diagnosis of worm gearbox based on adaptive CNN using amended gorilla troop optimization with quantum gate mutation strategy

The worm gearbox is a high-speed transmission system that plays a vital role in various industries. Therefore it becomes necessary to develop a robust fault diagnosis scheme for worm gearbox. Due to advancements in sensor technology, researchers from academia and industries prefer deep learning models for fault diagnosis purposes. The optimal selection of hyperparameters (HPs) of deep learning models plays a significant role in stable performance. Existing methods mainly focused on manual tunning of these parameters, which is a troublesome process and sometimes leads to inaccurate results. Thus, exploring more sophisticated methods to optimize the HPs automatically is important. In this work, a novel optimization, i.e. amended gorilla troop optimization (AGTO), has been proposed to make the convolutional neural network (CNN) adaptive for extracting the features to identify the worm gearbox defects. Initially, the vibration and acoustic signals are converted into 2D images by the Morlet wavelet function. Then, the initial model of CNN is developed by setting hyperparameters. Further, the search space of each Hp is identified and optimized by the developed AGTO algorithm. The classification accuracy has been evaluated by AGTO-CNN, which is further validated by the confusion matrix. The performance of the developed model has also been compared with other models. The AGTO algorithm is examined on twenty-three classical benchmark functions and the Wilcoxon test which demonstrates the effectiveness and dominance of the developed optimization algorithm. The results obtained suggested that the AGTO-CNN has the highest diagnostic accuracy and is stable and robust while diagnosing the worm gearbox.

eess.SP↗

arXiv2024

Constraining non-unitary neutrino mixing using matter effects in atmospheric neutrinos at INO-ICAL

The mass-induced neutrino oscillation is a well established phenomenon that is based on the unitary mixing among three light active neutrinos. Remarkable precision on neutrino mixing parameters over the last decade or so has opened up the prospects for testing the possible non-unitarity of the standard 3$ν$ mixing matrix, which may arise in the seesaw extensions of the Standard Model due to the admixture of three light active neutrinos with heavy isosinglet neutrinos. Because of this non-unitary neutrino mixing (NUNM), the oscillation probabilities among the three active neutrinos would be altered as compared to the probabilities obtained assuming a unitary 3$ν$ mixing matrix. In such a NUNM scenario, neutrinos can experience an additional matter effect due to the neutral current interactions with the ambient neutrons. Atmospheric neutrinos having access to a wide range of energies and baselines can experience a significant modifications in Earth's matter effect due to NUNM. In this paper, we study in detail how the NUNM parameter $α_{32}$ affects the muon neutrino and antineutrino survival probabilities in a different way. Then, we place a comparable and complementary constraint on $α_{32}$ in a model independent fashion using the proposed 50 kt magnetized Iron Calorimeter (ICAL) detector under the India-based Neutrino Observatory (INO) project, which can efficiently detect the atmospheric $ν_μ$ and $\barν_μ$ separately in the multi-GeV energy range. Further, we discuss the advantage of charge identification capability of ICAL and the impact of uncertainties in oscillation parameters while constraining $α_{32}$. We also compare the $α_{32}$ sensitivity of ICAL with that of future long-baseline experiments DUNE and T2HK in isolation and combination.

hep-ph↗