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Semi-empirical formula for two-neutrino double-β decay

Physical Review C 2025年第2期111卷 024307-024307页

作者： O. Niţescu F. Šimkovic Faculty of Mathematics Physics and Informatics Comenius University in Bratislava 842 48 Bratislava Slovakia International Centre for Advanced Training and Research in Physics P.O. Box MG12 077125 Măgurele Romania “Horia Hulubei” National Institute of Physics and Nuclear Engineering 30 Reactorului POB MG-6 RO-077125 Bucharest-Măgurele Romania Institute of Experimental and Applied Physics Czech Technical University in Prague 110 00 Prague Czech Republic

We propose a semi-empirical formula (SEF) for calculating the nuclear matrix elements (NMEs) for two-neutrino double-β decay. The SEF's dependence on the proton and neutron numbers, the pairing, isospin, and deformation properties of the initial and final nuclei is inspired by the insights offered by nuclear many-body methods and trends in experimental data. Compared with the previous phenomenological and nuclear models, the SEF yields the best agreement with the experimental NMEs. Its stability and predictive power are cross validated, and predictions are provided for nuclear systems of experimental interest.

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Latent Space Representation of Electricity Market Curves for Improved Prediction Efficiency

arXiv

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arXiv 2025年

作者： Výboh, Martin Chladná, Zuzana Grmanová, Gabriela Lucká, Mária Kempelen Institute of Intelligent Technologies Sky Park Offices Bottova 7939/2A Bratislava811 09 Slovakia Department of Applied Mathematics and Statistics Faculty of Mathematics Physics and Informatics Comenius University Mlynska dolina F1 Bratislava842 48 Slovakia

This work presents a three-phase ML prediction framework designed to handle a high dimensionality and multivariate time series character of the electricity market curves. In the preprocessing phase, we transform the original data to achieve a unified structure and mitigate the effect of possible outliers. Further, to address the challenge of high dimensionality, we test three dimensionality reduction techniques (PCA, kPCA, UMAP). Finally, we predict supply and demand curves, once represented in a latent space, with a variety of machine learning methods (RF, LSTM, TSMixer). As our results on the MIBEL dataset show, a high dimensional structure of the market curves can be best handled by the nonlinear reduction technique UMAP. Regardless of the ML technique used for prediction, we achieved the lowest values for all considered precision metrics with a UMAP latent space representation in only two or three dimensions, even when compared to PCA and kPCA with five or six dimensions. Further, we demonstrate that the most promising machine learning technique to handle the complex structure of the electricity market curves is a novel TSMixer architecture. Finally, we fill the gap in the field of electricity market curves prediction literature: in addition to standard analysis on the supply side, we applied the ML framework and predicted demand curves too. We discussed the differences in the achieved results for these two types of curves. © 2025, CC BY.

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Radiative and exchange corrections for two-neutrino double-β decay

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Physical Review C 2025年第3期111卷 035501-035501页

作者： O. Niţescu F. Šimkovic Faculty of Mathematics Physics and Informatics Comenius University in Bratislava 842 48 Bratislava Slovakia International Centre for Advanced Training and Research in Physics (CIFRA) P.O. Box MG-12 RO-077125 Bucharest-Măgurele Romania “Horia Hulubei” National Institute of Physics and Nuclear Engineering 30 Reactorului P.O. Box MG6 RO-077125 Bucharest-Măgurele Romania Institute of Experimental and Applied Physics Czech Technical University in Prague 110 00 Prague Czech Republic

We investigate the impact of radiative and atomic exchange corrections in the two-neutrino double-beta (2νββ) decay of Mo100. In the calculation of the exchange correction, the electron wave functions are obtained from a modified Dirac-Hartree-Fock-Slater self-consistent framework that ensures orthogonality between continuum and bound states. The atomic exchange correction causes a steep increase in the low-energy region of the single-electron spectrum, consistent with previous studies on β decay, while the radiative correction primarily accounts for a 5% increase in the decay rate of Mo100. When combined, the radiative and exchange effects cause a leftward shift of approximately 10 keV in the maximum of the summed electron spectrum. This shift may impact current constraints on parameters governing potential new physics scenarios in 2νββ decay. The exchange and radiative corrections are introduced on top of our previous description of 2νββ decay, where we used a Taylor expansion for the lepton energy parameters within the nuclear matrix elements denominators. This approach results in multiple components for each observable, controlled by the measurable ξ31 and ξ51 parameters. We explore the effects of different ξ31 and ξ51 values, including their experimental measurements, on the total corrected spectra. These refined theoretical predictions can serve as precise inputs for double-beta decay experiments investigating standard and new physics scenarios within 2νββ decay.

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Exploiting Circular Shifts for Efficient Chaotic Image Encryption

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IEEE Access 2025年 13卷 92997-93016页

作者： Lazaros Moysis Marcin Lawnik Wassim Alexan Sotirios K. Goudos Murilo S. Baptista George F. Fragulis Department of Electrical and Computer Engineering University of Western Macedonia Kozani Greece Department of Mechanical Engineering University of Western Macedonia Kozani Greece Department of Mathematical Methods in Technics and Informatics Faculty of Applied Mathematics Silesian University of Technology Gliwice Poland Communications Department Faculty of Information Engineering and Technology German University in Cairo Cairo Egypt ELEDIA@AUTH School of Physics Aristotle University of Thessaloniki Thessaloniki Greece Department of Physics Institute for Complex Systems and Mathematical Biology SUPA The University of Aberdeen Aberdeen U.K.

This work presents a chaotic image encryption algorithm that acts on the binary level of the image for effective permutation, and on the byte level for substitution. The permutation step combines actions of bit level rearranging, and bit shuffling. Circular shift operations are used for bit shuffling, to reduce the execution time. Circular shifts are also applied to shuffle the permutation and substitution rules, effectively increasing security at a very low execution cost. The encryption keys are plaintext dependent, and a key mixing step in included, so that each part of the key affects all the subsequent encryption operations. For the encryption, a new Soboleva hyperbolic tangent based map is first designed. The dynamical behavior of the map is studied and shows robust chaos, and an absence of equilibria, meaning that it can generate hidden attractors. This map is used as an entropy source, along with a chaotic pseudo random number generator (PRNG). The encryption process shows a good performance under a collection of tests, and has also a low execution time, 0.0134 sec for a $256\times 256$ image, 0.0530 sec for a $512\times 512$ image, and 0.2050 sec for a $1024\times 1024$ image. So the proposed algorithm is a viable option for fast, efficient, and secure data encryption.

关键词： Encryption Security Chaotic communication Generators Robustness Matrices Costs Standards Real-time systems Computational efficiency

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Spring-mass behavior of solitons under the influence of an external force field within the modified Korteweg-de Vries equation

arXiv

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arXiv 2025年

作者： Flamarion, Marcelo V. Pelinovsky, Efim Melnikov, Ioann Departamento Ciencias—Sección Matemáticas Pontificia Universidad Católica del Perú Av. Universitaria 1801 San Miguel Lima15088 Peru Institute of Applied Physics 46 Uljanov Str. Nizhny Novgorod603155 Russia Faculty of Informatics Mathematics and Computer Science HSE University Nizhny Novgorod603155 Russia

We investigate the interaction of solitons with an external periodic field within the framework of the modified Korteweg-de Vries (mKdV) equation. In the case of small perturbation a simple dynamical system is used to describe the soliton behaviour. Equilibrium points of this dynamical system are computed when the external force travels at a constant speed. Assuming that the external force moves with sinusoidal speed, we demonstrate that the soliton behavior is qualitatively similar to the constant-speed case. Besides, a resonant frequency is derived from the asymptotic theory without using the classical broad force approximation. The results obtained from the dynamical system are compared with fully direct numerical simulations, which reveal that the soliton solution exhibits spiral-like behavior in the soliton amplitude versus soliton phase space. Moreover, when the external force oscillates at the resonant frequency, the trajectories in the soliton phase versus soliton amplitude exhibit chaotic behavior. Copyright © 2025, The Authors. All rights reserved.

关键词： Solitons

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Small shower CORSIKA simulations

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Chinese physics C 2021年第8期45卷 153-165页

作者： Tadeusz Wibig Faculty of Physics and Applied Informatics University of Lodz90-236 LodzPomorska 149/153Poland

Extensive Air Showers(EAS)induced by cosmic ray particles of very low energies,owing to the significantly steep cosmic ray energy spectrum,dominate the secondary particle flux measured by single detectors and small shower *** arrays connected in extended networks can be used to determine potentially interesting spatial correlations between showers,which may shed new light on the nature of ultra high-energy cosmic *** quantitative interpretation of showers recorded by small local arrays requires a methodology that differs from that used by ordinary large EAS arrays operating in the"knee"region and *** present"small EAS generator,"a semi-analytical method for integrating cosmic ray spectra over energies of interest and summing over the mass spectra of primary nuclei in arbitrary detector ***,we provide results on the EAS electron and muon fluxes and particle density spectra.

关键词： cosmic rays extensive air showers simulations shower particle density spectrum small EAS array

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VeloxQ: A Fast and Efficient QUBO Solver

arXiv

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arXiv 2025年

作者： Pawlowski, J. Tuziemski, J. Tarasiuk, P. Przybysz, A. Adamski, R. Hendzel, K. Pawela, L. Gardas, B. Institute of Theoretical Physics Faculty of Fundamental Problems of Technology Wroclaw University of Science and Technology Wroclaw50-370 Poland Quantumz.io Sp. z o.o. Pulawska 12/3 Warsaw02-566 Poland Institute of Theoretical and Applied Informatics Polish Academy of Sciences Baltycka 5 Gliwice44-100 Poland

We introduce VeloxQ, a fast and efficient solver for Quadratic Unconstrained Binary Optimization (QUBO) problems, which are central to numerous real-world optimization tasks. Unlike other physics-inspired approaches to optimization problems, such as quantum annealing and quantum computing, VeloxQ does not require substantial progress of technology to unlock its full potential. We benchmark VeloxQ against the state-of-the-art QUBO solvers based on emerging technologies. Our comparison includes quantum annealers, specifically D-Wave’s Advantage and Advantage2 prototype platforms, the digital-quantum algorithm designed to solve Higher-Order Unconstrained Binary Optimization (HUBO) developed by Kipu Quantum, physics-inspired algorithms: Simulated Bifurcation and Parallel Annealing and an algorithm based on tropical tensor networks. We also take into account modern developments of conventional algorithms: Branch and Bound algorithm, an optimal implementation of the brute-force algorithm and BEIT QUBO solver. Our results show that VeloxQ not only matches but often surpasses the mentioned solvers in solution quality and runtime. Additionally, VeloxQ demonstrates excellent scalability being the only solver capable of solving large-scale optimization problems, including up to 2×108 sparsely connected variables, that are currently intractable for its competitors. These findings position VeloxQ as a powerful and practical tool for tackling large-scale QUBO and HUBO problems, offering a compelling alternative to existing quantum and classical optimization methods. © 2025, CC BY.

关键词： Quantum computers

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Systematic computational screening and design of double perovskites Q₂LiMH₆ (Q = K, Rb;M = Ga, In, Tl) for efficient hydrogen storage: A DFT and AIMD approach

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Surfaces and Interfaces 2025年 67卷

作者： Hosen, Asif Mousa, Ahmad A. Nemati-Kande, Ebrahim Khan, Asif Nawaz Abu-Jafar, Mohammed S. Benassi, Enrico Elghmaz, E.A. EL-Gawaad, N.S. Abd Asad, Jihad Department of Materials Science and Engineering Khulna University of Engineering & Technology (KUET) Khulna 9203 Bangladesh Middle East University Amman 11831 Jordan Department of Physical Chemistry Chemistry Faculty Urmia University Urmia Iran Material Modeling and Simulation Lab Department of Physics University of Science & Technology Khyber Pakhtunkhwa Bannu 28100 Pakistan Department of Physics An-Najah National University Nablus Palestine Department of Physics Informatics and Mathematics University of Modena and Reggio Emilia via Giuseppe Campi 213/B Modena 41125 Italy Department of Physics King Khalid University Abha 61421 Saudi Arabia Muhayil Asir Applied College King Khalid University Abha 62529 Saudi Arabia Dep. of Physics Faculty of applied Science Palestine Technical University- Kadoorie Tukarem P 305 Palestine

The development of efficient hydrogen storage solutions is crucial for advancing the commercialization of hydrogen-based energy systems. Solid-state hydrogen storage is emerging as a highly promising method, attracting considerable interest and necessitating in-depth research efforts. This study systematically designs six novel solid-state hydrides: K₂LiGaH₆, K₂LiInH₆, K₂LiTlH₆, Rb₂LiGaH₆, Rb₂LiInH₆, and Rb₂LiTlH₆, using density functional theory (DFT). The objective is to thoroughly investigate their structural, elastic, opto-electronic, thermodynamic, and hydrogen storage characteristics. The dynamical stability was analyzed, and the resulting phonon dispersion curves confirm that these materials are stable. Furthermore, ab initio molecular dynamics (AIMD) simulations confirm the thermal stability of the hydrides at room temperature (300 K), as no structural deformation was observed. The band structure indicates that all materials exhibit indirect band gap semiconducting behavior, with band gap values spanning from 0.3 to 2 eV. Optical property analysis reveals that these hydrides are effective ultraviolet absorbers, with a noticeable red shift in the absorption edge can be observed resulting from the variations of bandgap. All the hydrides demonstrate mechanical stability and exhibit brittle characteristics. The calculated gravimetric hydrogen storage capacities indicate that K₂LiGaH₆ has the highest capacity at 3.22 wt%, followed by K₂LiInH₆ (2.60 wt%), Rb₂LiGaH₆ (2.16 wt%), K₂LiTlH₆ (1.88 wt%), and Rb₂LiInH₆ (1.86 wt%), with Rb₂LiTlH₆ having the lowest value at 1.46 wt%. A decrease in storage capacity is observed when the cationic atom at the Q and M site in Q₂LiMH₆ is replaced, d

关键词： AIMD simulation Double perovskite hydrides First-principles study Hydrogen storage Physical properties

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Controlling the Output of a Generative Model by Latent Feature Vector Shifting

Controlling the Output of a Generative Model by Latent Featu...

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2023 World Symposium on Digital Intelligence for Systems and Machines, DISA 2023

作者： Belanec, Róbert Lacko, Peter Malinovská, Kristína Department of Applied Informatics Faculty of Mathematics Physics and Informatics Bratislava Slovakia

ISBN: (纸本)9798350343533

State-of-the-art generative models (e.g. StyleGAN3 [1]) often generate photorealistic images based on vectors sampled from their latent space. However, the ability to control the output is limited. Here we present our novel method for latent vector shifting for controlled output image modification utilizing semantic features of the generated images. In our approach we use a pre-trained model of StyleGAN3 that generates images of realistic human faces in relatively high resolution. We complement the generative model with a convolutional neural network classifier, namely ResNet34, trained to classify the generated images with binary facial features from the CelebA dataset. Our latent feature shifter is a neural network model with a task to shift the latent vectors of a generative model into a specified feature direction. We have trained latent feature shifter for multiple facial features, and outperformed our baseline method in the number of generated images with the desired feature. To train our latent feature shifter neural network, we have designed a dataset of pairs of latent vectors with and without a certain feature. Based on the evaluation, we conclude that our latent feature shifter approach was successful in the controlled generation of the StyleGAN3 generator. © 2023 IEEE.

关键词： Generative adversarial networks

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Solving rescheduling problems in heterogeneous urban railway networks using hybrid quantum–classical approach

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Journal of Rail Transport Planning and Management 2025年 34卷

作者： Koniorczyk, Mátyás Krawiec, Krzysztof Botelho, Ludmila Bešinović, Nikola Domino, Krzysztof HUN-REN Wigner Research Centre for Physics Konkoly-Thege Miklós út 29-33. Budapest1121 Hungary Faculty of Transport and Aviation Engineering Silesian University of Technology Akademicka 2A Gliwcie44-100 Poland Institute of Theoretical and Applied Informatics Polish Academy of Sciences Baltycka 5 Gliwcie44-100 Poland Joint Doctoral School Silesian University of Technology Akademicka 2A Gliwcie44-100 Poland "Friedrich List" Faculty of Transport and Traffic Sciences Technical University of Dresden Dresden01069 Germany

We address the applicability of a hybrid quantum–classical heuristics for practical railway rescheduling management problems. We build an integer linear programming model and solve it with D-Wave's quantum–classical hybrid solver (CQM) as well as with CPLEX, for comparison. The proposed approach is demonstrated on a real-life heterogeneous urban network in Poland, including both single- and multi-track segments. All the requirements posed by the operator of the network are included in the model. The computational results demonstrate the readiness for application and the benefits of quantum–classical hybrid solvers in a realistic railway scenario: they yield acceptable solutions on time, which is a critical requirement in a rescheduling situation. In particular, CQM as a probabilistic heuristic solver provides a number of feasible, close-to-optimal solutions the dispatcher can choose from. © 2025 Elsevier Ltd

关键词： Integer programming

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