Indian Journal of Physics最新文献

{"title":"Holographic dark energy inflation in (f(T,{mathcal {T}})) gravity","authors":"Samson S. Hounmenou,&nbsp;Ines G. Salako,&nbsp;V. A. Monwanou,&nbsp;C. E. M. Batista,&nbsp;Etienne Baffou,&nbsp;L. D. Gbetoho,&nbsp;Stephane Houndjo","doi":"10.1007/s12648-025-03611-2","DOIUrl":"10.1007/s12648-025-03611-2","url":null,"abstract":"<div><p>In the context of <span>(f(T,{mathcal {T}}))</span> gravity, where <span>(T)</span> denotes the torsion scalar and <span>({mathcal {T}})</span> signifies the trace of the energy-momentum tensor, our study delved into holographic inflation cosmology. Our investigation involved incorporating a holographic potential alongside three distinct types of <b>inflationary potentials</b> widely recognized in the scientific community. Our primary aim was to delineate the parameter regime governing the interplay between geometry and matter, crucial for describing scenarios of cosmological inflation. To achieve this, we derived the slow-roll parameters, enabling predictions of fundamental cosmological parameters such as the scalar spectral index <span>(n_s)</span>, the <b>tensor-to-scalar ratio</b> <span>(r)</span>, and the tensor spectral index <span>(n_T)</span>. These predictions were expressed in terms of parameters inherent to the <b>inflationary potential</b>. By comparing our results with those obtained in <b>Teleparallel gravity</b> (equivalent to General Relativity (GR)), we highlighted the significant influence of the parameter linking geometry and matter. This influence was underscored by comprehensive data presented in multiple tables, particularly within the framework of <span>(f(T,{mathcal {T}}))</span> gravity. Our practical findings not only underscore the significance of <b>geometry-matter interactions</b> but also demonstrate strong alignment with both <b>Planck 2018</b> and WMAP data, thereby bolstering the credibility and importance of our discoveries.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 11","pages":"4443 - 4457"},"PeriodicalIF":1.7,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of solar energetic particles: their source regions, flares and CMEs during solar cycles 23–24","authors":"Raj Kumar,&nbsp;Ramesh Chandra,&nbsp;Bimal Pande,&nbsp;Seema Pande","doi":"10.1007/s12648-025-03619-8","DOIUrl":"10.1007/s12648-025-03619-8","url":null,"abstract":"<div><p>In this work, we examine the association between solar active regions and 152 solar flares, coronal mass ejections, and solar energetic particle (SEP) events over solar cycles 23–24 (1997–2017). The Coordinated Data Analysis Workshops center's GOES data in the energy channel &gt; 10 MeV (Major SEPs; solar proton events) with flux ≥ 10 pfu was used for our investigation. For the associated activities, we have analyzed the data from space born satellites namely: SOHO/LASCO and SDO/AIA. We found a moderate correlation (55%) between SXR flux and sunspot area i.e., active regions with larger sunspot areas generally generate larger flares. We found that most of the SEPs are originated from the magnetically complex active regions i.e., hale class βγδ and β. Very few events were associated with unipolar active regions. Stronger GOES X-ray is linked to more impulsive events, as evidenced by the negative correlation (− 0.40) between X-ray flux and SEP duration. In the active region βγδ, the highest average SEP intensity (2051 pfu) was detected. In the data set used, only 10% SEPs are found impulsive in nature, while the remaining 90% are gradual in nature. All the impulsive events had SEP intensity less than 100 pfu and most of the CMEs associated with these events were decelerated CMEs. We discovered that the majority of faster CMEs are linked to the most complex magnetic active regions. This indicates that high speed CMEs are produced by magnetically complex active regions. We discovered that 58 SEP events in our data set are linked to accelerated CMEs, while 82 are linked to decelerated CMEs. The highest average CME width is found corresponding to magnetically most complex active regions βδ, γδ, αγδ and βγδ, which shows that large CMEs are the consequences of magnetically complex active regions.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 10","pages":"3593 - 3605"},"PeriodicalIF":1.7,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144880988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of the effective π-conjugation in anthracenyl chalcone for enhanced nonlinear optical properties and optical limiting potential","authors":"Siti Hajar Wahida Jamaludin,&nbsp;Dian Alwani Zainuri,&nbsp;Mundzir Abdullah,&nbsp;Ibrahim Abdul Razak,&nbsp;Suhana Arshad","doi":"10.1007/s12648-025-03612-1","DOIUrl":"10.1007/s12648-025-03612-1","url":null,"abstract":"<div><p>The modulation of effective π-conjugation in anthracenyl chalcone derivatives is investigated to enhance their nonlinear optical (NLO) properties and optical limiting potential. Two derivatives, (E)-1,3-di(anthracen-9-yl)prop-2-en-1-one (<b>1</b>) and (E)-1-(anthracen-9-yl)-3-(naphthalen-2-yl)prop-2-en-1-one (<b>2</b>), are synthesized and characterized using Fourier Transform Infrared-Attenuated Total Reflectance (FTIR-ATR) spectroscopy, Nuclear Magnetic Resonance (¹H and ¹³C NMR), and UV–Visible spectroscopy. The absorption spectra reveal strong absorption in the 383–390 nm range, indicative of enhanced electron-accepting capabilities. Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) calculations, employing the CAM-B3LYP/6–311 +  + G(d,p) approach, provide insights into the molecular electronic properties, including Frontier Molecular Orbitals (FMOs), Global Reactivity Descriptors (GRD), and hyperpolarizabilities. Natural Bond Orbital (NBO) analysis confirms significant intramolecular charge transfer, supporting the compounds’ potential for NLO applications. Notably, compound <b>1</b> exhibits a stronger third-order NLO response (χ³ = 3.99 × 10^-6 esu) compared to compound 2 (5.52 × 10^-6su), attributed to its extended conjugation and favorable electronic structure. These findings establish a strong correlation between π-conjugation modulation and enhanced NLO performance, positioning anthracenyl chalcones as promising candidates for advanced optical limiting applications.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 10","pages":"3957 - 3975"},"PeriodicalIF":1.7,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144880940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of density functional theory in analyzing the structural, optoelectronic, and thermodynamics properties of RbCrCl3 and mixed NaGeCl2F perovskites: a first-principles approach","authors":"Bewar M. Ahmad","doi":"10.1007/s12648-025-03620-1","DOIUrl":"10.1007/s12648-025-03620-1","url":null,"abstract":"<div><p>In this study, the structural, electronic, optical and thermodynamic properties of the cubic perovskite RbCrCl₃ and mixed perovskite tetragonal phase NaGeCl₂F are investigated. The perovskites have become interesting due to their good optical and electronic properties, such as, the large band gaps and the high carrier mobility. For the exchange–correlation (XC) energy density functional theory (DFT) was employed and routine ab-initio calculations with the general gradient approximation (GGA) of Perdew–Burke–Ernzerhof (PBE) as the chief means of solving XC energy. From the density of state (DOS), the band structure, and structural characteristics, can be studied using DFT approach. Thus, an analysis of the results obtained by calculating the band structure which shows that NaGeCl₂F has a direct band gap, whereas the band gap of RbCrCl₃ is indirect. Further investigations, the optical properties of these perovskites were studied through the obtained dielectric function, refractive index and absorption coefficient. Moreover, Gibbs2 employs Quasiharmonic Approximation (QHA) was used in the calculations of the thermodynamic properties of the studied structures. The results suggest that these halide perovskites can be prospective materials for optoelectronics devices because they can allow, reflect or absorb electricity from the electromagnetic spectrum. In the current investigation the derived Volume (V), bulk modulus (B), entropy (S), free Gibbs energy (G), specific heat at constant pressure (C_p) and at constant volume (C_v) with respect to pressure successively at higher temperatures in kelvin. The results show that if the pressure rises then both B and G show a moderate increase in visibility to allow their use in geophysical simulation and pressure equipment’s. It is noted form the results of thermodynamics that the value of C_p, C_v and S for NaGeCl₂F slightly decrease with pressure. Nevertheless, for RbCrCl₃ these values are not significantly variable with pressure, so that these materials can be used for high-pressure sensors. The real applications of the selected perovskites, RbCrCl₃, with its indirect bandgap, is an ideal candidate for photodetectors and photovoltaic devices due to its long carrier diffusion lengths, enabling efficient photon interaction and charge collection. In contrast, NaGeCl₂F, with its direct bandgap, is well-suited for LEDs and lasers, where high radiative recombination rates enable efficient photon emission. The combination of these structures provides flexibility in the design of devices, with direct bandgap excelling in light-emitting applications and indirect bandgap supporting long-distance carrier transport for energy-harvesting devices.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 10","pages":"3777 - 3789"},"PeriodicalIF":1.7,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144880918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SADAR: SANS data reduction software at National Research and Innovation Agency of Indonesia","authors":"B. Bharoto,&nbsp;A. Patriati,&nbsp;N. Suparno,&nbsp;A. Ikram,&nbsp;I. Sumirat,&nbsp;A. Ramadhani,&nbsp;I. Hafid,&nbsp;F. Akbar,&nbsp;R. Damayanti,&nbsp;R. Ridwan,&nbsp;A. Rachminisari","doi":"10.1007/s12648-025-03613-0","DOIUrl":"10.1007/s12648-025-03613-0","url":null,"abstract":"<div><p>A dedicated software package, SADAR, has been developed for the reduction of two-dimensional Small Angle Neutron Scattering (SANS) data acquired from the SN2 instrument at the National Research and Innovation Agency (BRIN), Indonesia. SADAR facilitates essential data corrections, including background and sample holder subtraction, instrument parameter determination (beam center on 2D detector, transmission factor of the sample, detector efficiency), and conversion to scattering intensity as a function of momentum transfer, I(Q). Output data are stored in ASCII format, enabling subsequent advanced analysis. Validation using an AgBeh standard demonstrated the software’s efficacy, with the identification of the characteristic lamellar structure first Bragg peak at Q = 0.1089 Å¹. SADAR provides a robust and reliable tool for accurate and precise SANS data processing for SN2 instrument users. The SADAR was developed using the Python programming language to ensure compatibility with wide range of computer platforms.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 11","pages":"4169 - 4180"},"PeriodicalIF":1.7,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the potential of lead-free ASnI2Br-based tandem 4 T and 2 T configurations: a comprehensive TCAD analysis","authors":"H. El-Demsisy,&nbsp;A. Shaker,&nbsp;M. Asham,&nbsp;I. Maged,&nbsp;T. Abdolkader","doi":"10.1007/s12648-025-03600-5","DOIUrl":"10.1007/s12648-025-03600-5","url":null,"abstract":"<div><p>To meet the growing demand for eco-friendly solar technologies, lead-free perovskite (PVK) materials are emerging as promising alternatives to their lead-based counterparts. Among these, ASnI₂Br stands out due to its suitable wide bandgap, making it a strong candidate for integration into both 4T and 2T tandem configurations. In pursuit of a fully eco-friendly solar cell design, we present the development of lead-free ASnI₂Br/Si tandem solar cells, offering a sustainable approach with high potential for efficiency improvements. First, the advancement of 4 T tandem cell efficiency is discussed. The main structure consists of FTO/PEDOT:PSS/ASnI₂Br-PVK/C₆₀/BCP/Ag inverted structure as the top cell and an n-type Si as the rear cell. Based on the simulation findings, the suggested top cell structure performs much better when TiO₂ is substituted as the electron transport layer instead of C₆₀, while CuSCN is found to be a good replacement for PEDOT:PSS as a hole transport layer. With these changes, the top cell's efficiency becomes 15.29%. In addition, optimizations for the bottom cell are carried out. Efficiencies for bare and filtered bottom cells reaching 23.97 and 12.53% are achieved, respectively, at 30 µm absorber thickness and 1 ms lifetime. With only two terminals, the 2 T cell has fewer manufacturing costs for the photovoltaic module than the 4 T cell. Thus, we introduce a design for a 2 T cell by converting the enhanced 4 T cell, while inverting the top cell to be compatible with the rear cell n-p structure. To ensure current matching, the correct thickness must be established for both sub-cells, where the thickness of the perovskite absorption layer rises from 200 to 545 nm. This led to reaching the matching point at a current equal to 16.35 mA/cm², and our simulation for the monolithic stacked 2T TSC produced a PCE of 24.28%.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 10","pages":"3737 - 3753"},"PeriodicalIF":1.7,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12648-025-03600-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144880836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel and reliable soliton solutions for nematicon liquid crystal models with various nonlinearities by the application of analytical method","authors":"A. Mumtaz,&nbsp;M. Shakeel,&nbsp;A. Manan,&nbsp;Nehad Ali Shah","doi":"10.1007/s12648-025-03603-2","DOIUrl":"10.1007/s12648-025-03603-2","url":null,"abstract":"<div><p>In this work, the Kerr and Parabolic Law features of the equation characterizing nematic liquid crystals are taken into account in order to create trigonometric, hyperbolic and rational type travelling wave solutions utilizing the (<i>G</i>′/<i>G</i>²)-expansion method. The travelling wave solutions that are obtained from the equation play a crucial role in the energy transfer within the liquid crystal soliton molecules. Additionally, the solitary wave behaviors seen in the generated travelling wave solutions for various constant values are examined. Kink type soliton, singular kink soliton, singular soliton, periodic soliton, singular periodic soliton, double soliton, dark-bright W-type soliton and compacton are obtained as the travelling wave solutions of the equation defining nematic liquid crystals incorporating Kerr and Parabolic Law property.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 11","pages":"4291 - 4309"},"PeriodicalIF":1.7,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visual entropy production estimator of stochastic thermodynamics and application to cyclic population","authors":"Si-Le Lin,&nbsp;Si-Yang Hao,&nbsp;Wei-Man Chen","doi":"10.1007/s12648-025-03610-3","DOIUrl":"10.1007/s12648-025-03610-3","url":null,"abstract":"<div><p>We propose a visualization method for estimating the entropy production(EP) based on stochastic thermodynamics without prior knowledge of the equation of motion. The entropy production of stochastic thermodynamics is summarized into several observable measurements. Given a time series of observations of a single trajectory, the entropy production in nonequilibrium steady states can be estimated. In numerical simulations of the Lotka–Volterra model, large entropy production is usually accompanied by large environmental forces, which will dominate the population growth. The same conclusion can be drawn from the entropy production of hare-lynx and the ancient Chinese population.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 11","pages":"4349 - 4355"},"PeriodicalIF":1.7,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Holographic reconstruction of k-essence model with Tsallis and the most generalized Nojiri-Odintsov version of holographic dark energy","authors":"Ulbossyn Ualikhanova,&nbsp;Aziza Altaibayeva,&nbsp;Surajit Chattopadhyay","doi":"10.1007/s12648-025-03606-z","DOIUrl":"10.1007/s12648-025-03606-z","url":null,"abstract":"<div><p>The holographic principle, which has its roots in string theory and black hole thermodynamics, connects the maximum distance of a quantum field theory to its infrared cutoff, which is correlated with the vacuum energy. The present study explores a reconstruction scheme for the k-essence form of dark energy with the most generalized version of holographic dark energy introduced in S. Nojiri, and S. D. Odintsov (2006) (Gen. Relativ. Gravit., 38 p: 1285-1304 ) and (S. Nojiri and S. D. Odintsov, 2017, European Physical Journal C, 77, pp.1-8 ). Here, in the initial phase of the study, we begin with a reconstruction scheme of the k-essence model with Tsallis holographic dark energy and finally with a highly generalized version of holographic dark energy with Nojiri-Odintsov generalization. Finally, we have studied the cosmological consequences of the k-essence dark energy with the generalized versions of holographic fluid.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 11","pages":"4433 - 4441"},"PeriodicalIF":1.7,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Moving front and dark solitary wave for couple of generalized nonlinear Schrödinger dynamical equations","authors":"Syed T. R. Rizvi,&nbsp;M. Gulshan Iqbal,&nbsp;Sarfaraz Ahmed,&nbsp;Ali Althobaiti,&nbsp;Aly R. Seadawy","doi":"10.1007/s12648-025-03599-9","DOIUrl":"10.1007/s12648-025-03599-9","url":null,"abstract":"<div><p>We study some optical pulses including dark solitary waves (DSWs), moving front solitons (MFSs) or optical shock type soliton, and periodic wave solution (PWSs) and some other solution for generalized Kundu-Eckhaus equation (KEE) and generalized nonlinear Schrödinger equation (GNLSE) using ansatz transformations. We derived the propagation dynamics for short light pulses in optical fiber for our governing models. The generalized KEE describes the propagation of ultra short femto pulses in optical fiber, while GNLSE discuses the picosecond pulses in optical fiber. The MFSs are a type of soliton that possess a sharp transition or discontinuity in the optical field. The DSWs represent a fascinating phenomenon in nonlinear wave propagation, offering unique opportunities for controlling and manipulating wave fields in various physical systems. The PWSs in optical fibers show potential applications in optical communications, where they can be utilized for generating multiplexing signals and frequency combs. We also illustrate our solutions using graphs in different dimensions.</p></div>","PeriodicalId":584,"journal":{"name":"Indian Journal of Physics","volume":"99 10","pages":"3837 - 3848"},"PeriodicalIF":1.7,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144880909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}