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Modified Masses and Parallaxes of Close Binary Systems: HD 39438

Research in astronomy and Astrophysics 2023年第11期23卷 31-37页

作者： Suhail Masda ZTYousef Mashhoor Al-Wardat Awni Al-Khasawneh Department of Physics Mahrah UniversityMahrahYemen Department of Physics Hadhramout UniversityMukallaYemen Department of Applied Physics Faculty of Science and TechnologyUniversiti Kebangsaan Malaysia43600 UKM BangiSelangorMalaysia Department of Applied Physics and Astronomy and Sharjah Academy for AstronomySpace Sciences and TechnologyUniversity of SharjahP.O.Box 27272 SharjahUnited Arab Emirates Department of Physics Al al-Bayt UniversityMafraq 25113Jordan

We present the detailed fundamental stellar parameters of the close visual binary system HD 39438 for the first time. We used Al-Wardat's method for analyzing binary and multiple stellar systems. The method implements Kurucz's plane parallel model atmospheres to construct synthetic spectral energy distributions(SEDs) for both components of the system. It then combines the results of the spectroscopic analysis with the photometric analysis and compares them with the observed ones to construct the best synthetic SED for the combined system. The analysis gives the precise fundamental parameters of the individual components of the system. Based on the positions of the components of HD 39438 on the H-R diagram, and evolutionary and isochrone tracks, we found that the system belongs to the main sequence stars with masses of 1.24 and 0.98 solar masses for the components A and B, respectively, and age of 1.995 Gyr for both components. The main result of HD 39438 is new dynamical parallax, which is estimated to be 16.689 ± 0.03 mas.

关键词： methods:analytical techniques:photometric (stars:)binaries:visual techniques:spectroscopic

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Testing Discrete Symmetries in Ortho-Positronium Decays with the J-PET Detector 9

Testing Discrete Symmetries in Ortho-Positronium Decays with...

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9th Meeting on CPT and Lorentz Symmetry, CPT 2022

作者： Czerwiński, E. Marian Smoluchowski Institute of Physics Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Kraków30-348 Poland Center for Theranostics Jagiellonian University Kraków Poland

ISBN: (纸本)9789811275388

A first result related to a CPT test in the decay of ortho-positronium based on data collected by means of the J-PET detector is already available,1 and a new test of CP symmetry is under investigation.2 Both results are based on the determination of angular correlations between momenta of gamma rays and other vector properties of the investigated system.3 Here, arguments for the possible usage of data collected by the J-PET group to test CPT symmetry within the Standard-Model Extension framework4 are shortly presented. © 2023 World Scientific Publishing Co. Pte. Ltd.

关键词： Gamma rays

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Chern-Simons gravitational term coupled to an isocurvature field

arXiv

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arXiv 2025年

作者： Orlando, Giorgio Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Krakow30-348 Poland

The Chern-Simons gravitational term during inflation is usually coupled to the inflaton field. The resulting theory suffers from ghost-field formation in the tensor sector, which limits the observational effects of P-violation on cosmological correlators. In this work, we consider the Chern-Simons term coupled to an isocurvature component in a multi-field model of inflation. Since the resulting theory does not affect the quadratic action of tensor perturbations, ghost fields do not appear. This operator provides (P-violating) interactions between the isocurvature perturbation and the curvature and tensor perturbations. We show that combining these couplings with interactions between the curvature and isocurvature components coming from a turning trajectory, the resulting 〈sst〉PV non-Gaussianities can reach fNLsst,PV = BPVζζh(k, k, k)/Pζ2(k) ∼ O(1) within the parameter space of the theory. Our result motivates the systematic study of the Chern-Simons gravitational term coupled to isocurvature fields in multi-field models of inflation with couplings between the curvature and isocurvature fields or other mechanisms that transfer effects on the isocurvature field into the curvature field. Copyright © 2025, The Authors. All rights reserved.

关键词： Tensors

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Primordial full bispectra from the general bounce cosmology

arXiv

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arXiv 2025年

作者： Akama, Shingo Faculty of Physics Astronomy and Applied Computer Science Jagiellonian University Krakow30-348 Poland

Primordial non-Gaussianities are key quantities to test early universe scenarios. In this paper, we compute full bispectra of scalar and tensor perturbations generated during a contracting phase in a general bounce model. The general bounce model consists of two branches: one realizes scale-invariant scalar and tensor power spectra from perturbations whose amplitudes become constant on superhorizon scales, as in de Sitter inflation, while the other realizes scale-invariant power spectra from perturbations whose amplitudes grow on superhorizon scales, as in matter bounce cosmology. We study the auto- and cross-bispectra originating from the scale-invariant scalar and tensor perturbations in these two branches. We investigate the amplitudes and shapes of non-Gaussianities and find that the differences between the two branches manifest for equilateral and squeezed momentum triangle configurations. In particular, one of the branches in which the superhorizon perturbations are conserved reproduces the so-called Maldacena’s consistency relation. By examining perturbativity conditions and considering current observational constraints on primordial non-Gaussianities, we also find a viable parameter space in which both theoretical and observational constraints are satisfied simultaneously. © 2025, CC BY.

关键词： Tensors

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CMTJ:Simulation package for analysis of multilayer spintronic devices

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npj Computational Materials 2023年第1期9卷 1804-1813页

作者： Jakub Mojsiejuk Sławomir Ziętek Krzysztof Grochot Witold Skowroński Tomasz Stobiecki Institute of Electronics AGH University of Science and TechnologyAl.Mickiewicza 30Kraków 30-059Poland Faculty of Physics and Applied Computer Science AGH University of Science and TechnologyAl.Mickiewicza 30Kraków 30-059Poland

We present CMTJ—a simulation package for large-scale macrospin analysis of multilayer spintronics *** from conventional simulations,such as magnetoresistance and magnetisation hysteresis loops,CMTJ implements a mathematical model of dynamic experimental techniques commonly used for spintronics devices characterisation,for instance:spin diode ferromagnetic resonance,pulse-induced microwave magnetometry,or harmonic Hall voltage *** find that macrospin simulations offer a satisfactory level of agreement,demonstrated by a variety of *** a unified simulation package,CMTJ aims to accelerate wide-range parameter search in the process of optimising spintronics devices.

关键词： multilayer analysis hysteresis

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QCD Dynamics and Hadron Production in High-Energy Nuclear Collisions at LHCb

QCD Dynamics and Hadron Production in High-Energy Nuclear Co...

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2023 European Physical Society Conference on High Energy physics, EPS-HEP 2023

作者： Bashir, Saliha Faculty of Physics and Applied Computer Science AGH University of Krakow Al. Mickiewicza 30 Krakow30-059 Poland

This study investigates dijet and neutral pion production in high-energy nuclear collisions in the LHCb detector. The obtained measurements offer crucial insights into Quantum Chromodynamics (QCD), understanding of parton distribution functions, nuclear structure, and particle production dynamics. Specifically, the nuclear modification factor for neutral pions in proton-lead collisions at 8.16 TeV reveal notable first evidence enhancement in the backward region providing constraints on models of nuclear structure. Furthermore, the inclusive bb¯ and cc¯-dijet production cross-sections in the forward region of pp collisions at 13 TeV align with next-to-leading order theoretical predictions. These findings on dijet and neutral pion production offer complementary perspectives on PDFs and nuclear structure, crucial for comprehending QCD dynamics in high-energy nuclear collisions and refining theoretical models. © Copyright owned by the author(s) under the terms of the Creative Commons.

关键词： Distribution functions

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Reconstruction techniques and physics case for displaced tracks and vertices at LHC 32

Reconstruction techniques and physics case for displaced tra...

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32nd International Workshop on Vertex Detectors, VERTEX 2023

作者： Oblakowska-Mucha, Agnieszka Faculty of Physics and Applied Computer Science AGH University of Krakow Al. Mickiewicza 30 Krakow30-059 Poland

The primary focus of the LHC experiments was the observation of Standard Model particles and the search for unexplored signatures indicative of New physics. Given the current discoveries and measurements done so far, the detectors and the trigger architecture are being changed to allow for the searches of long-lived particles. LHCb's trackers have excelled in the precise reconstruction of heavy flavour hadrons, and the experiment is now at the forefront of designing flexible trigger systems. Similarly, ATLAS and CMS, with their precise trackers, are also exploring new avenues by implementing innovative triggers to search for long-lived particles. The techniques of the reconstruction of displaced tracks and vertices in the upgraded LHCb detector, complementary with other general-purpose detectors at the LHC, are presented in this proceedings. © Copyright owned by the author(s)

关键词： Hadrons

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Bang-bang preparation of quantum many-body ground states in two dimensions: Optimization of the algorithm with a two-dimensional tensor network

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Physical Review B 2024年第23期109卷 235124-235124页

作者： Yintai Zhang Jacek Dziarmaga Doctoral School of Exact and Natural Sciences Institute of Theoretical Physics Faculty of Physics Astronomy and Applied Computer Science Mark Kac Center for Complex Systems Research

A bang-bang (BB) algorithm prepares the ground state of a two-dimensional (2D) quantum many-body Hamiltonian H=H1+H2 by evolving an initial product state alternating between H1 and H2. We use the neighborhood tensor update to simulate the BB evolution with an infinite pair-entangled projected state (iPEPS). The alternating sequence is optimized with the final energy as a cost function. The energy is calculated with a tangent space power method for the sake of its stability. The method is benchmarked in the 2D transverse field quantum Ising model near its quantum critical point against a ground state obtained with variational optimization of the iPEPS. The optimal BB sequence differs nonperturbatively from a sequence simulating quantum annealing or adiabatic preparation (AP) of the ground state. The optimal BB energy converges with the number of bangs much faster than the optimal AP energy.

关键词： Quantum control Ising model Tensor network methods

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Far-field optical propagators with user-defined object-plane pixel size for ptychography

Optics Continuum

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Optics Continuum 2025年第4期4卷 804-825页

作者： Pelekanidis, Antonios Eikema, Kjeld S. E. Witte, Stefan Advanced Research Center for Nanolithography Science Park 106 Amsterdam1098 XG Netherlands Department of Physics and Astronomy Vrije Universiteit De Boelelaan 1105 Amsterdam1081 HV Netherlands Imaging Physics Department Faculty of Applied Sciences Delft University of Technology Lorentzweg 1 Delft Netherlands

Lensless imaging techniques have been developed to visualize objects with high robustness and unprecedented resolution. Lensless imaging is based on the numerical reconstruction of the transmission or reflection function of a sample from optical diffraction measurements. Specifically, coherent diffractive imaging (CDI) and ptychography involve an iterative process of numerical propagation of coherent light waves between the sample and detector plane. However, in the standard propagation models, the pixel size of the reconstructed object image is typically fixed and wavelength-dependent, which limits CDI and broadband ptychography. Here we investigate three propagation models for far-field propagation that allow user-defined pixel size at the object plane. These propagators are the two-step Fresnel, scaled angular spectrum, and chirp-Z transform. We derive their analytical expressions and observe that all three models are mathematically equivalent, although they have a different physical origin. Each propagator can be written in two distinct versions, which conceptually represent propagation via different intermediate planes. We perform propagation simulations and ptychographic reconstructions on experimental data to compare the performance of these two different versions. We also investigate how sampling bandwidth requirements can affect the model accuracy due to physical errors associated with cropping of high spatial frequencies. Our results show that the choice of the intermediate plane can affect the reconstruction quality due to different sampling bandwidth requirements, which enables a wider choice of pixel sizes in the object plane. Our analysis provides guidelines for selecting an optimized object pixel size when performing reconstructions on broadband CDI and ptychography data. © 2025, Optica Publishing Group (formerly OSA). All rights reserved.

关键词： Z transforms

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Video classification for efficient data storage using deep learning: a comparison of sequential and simultaneous feature extraction methods

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Multimedia Tools and Applications 2025年第6期84卷 3071-3094页

作者： Dang Thi, Phuc Nguyen Dang, Hoang Thi Doan Huu, Phuc Dau Sy, Hieu Department of Computer Science Faculty of Information Technology Industrial University of Ho Chi Minh City 12 Nguyen Van Bao Ho Chi Minh City7000 Viet Nam Department of Applied Physics Faculty of Applied Science University of Technology - Viet Nam National University HCMC To Hien Thanh Ho Chi Minh City7000 Viet Nam

Optimizing camera information storage is a critical issue due to the increasing data volume and a large number of daily surveillance videos. In this study, we propose a deep learning-based system for efficient data storage. Videos captured by cameras are classified into four categories: no action, normal action, human action, and dangerous action. Videos without action or with normal action are stored temporarily and then deleted to save storage space. Videos with human action are stored for easy retrieval, while videos with dangerous action are promptly alerted to users. In the paper, we propose two approaches using deep learning models to address the video classification problem. The first approach is a separate approach, where pretrained CNN models extract features from video frame images. These features are then passed through RNN, Transformer models to extract relationships between them. The goal of this approach is to delve into extracting features of objects in the video. The proposed models include VGG16, InceptionV3 combined with LSTM, BiLSTM, Attention, and Vision Transformer. The next approach combines CNN and LSTM layers simultaneously through models like ConvLSTM and LRCN. This approach aims to help the model simultaneously extract object features and their relationships, with the goal of reducing model size, accelerating the training process, and increasing object recognition speed when deployed in the system. In Approach 1, we construct and refine network architectures such as VGG16+LSTM, VGG16+Attention+LSTM, VGG16+BiLSTM, VGG16+ViT, InceptionV3+LSTM, InceptionV3+Attention+LSTM, InceptionV3+BiLSTM. In Approach 2, we build a new network architecture based on the ConvLSTM and LRCN model. The training dataset, collected from real surveillance cameras, comprises 3315 videos labeled into four classes: no action (1018 videos), actions involving people (832 videos), dangerous actions (751 videos), and normal actions (714 videos). Experimental results show t

关键词： Deep learning

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