The European Physical Journal Plus最新文献

{"title":"Tidal disruption events: opportunities in the upcoming decade","authors":"Taeho Ryu","doi":"10.1140/epjp/s13360-026-08322-z","DOIUrl":"10.1140/epjp/s13360-026-08322-z","url":null,"abstract":"<div><p>We are living in an exciting era of wide-field time-domain surveys, which are transforming our understanding of short-lived (transient) phenomena. Nuclear transients, those that occur in galactic nuclei, uniquely probe the inner parsecs of galaxies that are otherwise inaccessible beyond the Milky Way. Among these events, tidal disruption events (TDEs), in which a star is destroyed by a supermassive black hole and a luminous electromagnetic flare generated in the process can briefly outshine its host galaxy, have become a focal point of attention. Since the first theoretical models in the late 1980 s and the earliest observational candidates in the late 1990 s, an expanding sample of TDEs has revealed a number of unexpected behaviors that challenge the classical picture. Many of these puzzles remain unresolved. In this article, we highlight several of these open questions and discuss how ongoing and upcoming observational programs and facilities, such as the Vera C. Rubin Observatory’s Legacy Survey of Space and Time and the Ultraviolet Transient Astronomy Satellite, may provide the observational leverage needed to address them.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-08322-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Reeb–Wolf improved Landauer principle for hairy black holes via gravitational decoupling","authors":"J. Andrade,&nbsp;J. O. Cedeño,&nbsp;M. Zeeshan Gul,&nbsp;D. Santana,&nbsp;Jiří Svozilík","doi":"10.1140/epjp/s13360-026-08345-6","DOIUrl":"10.1140/epjp/s13360-026-08345-6","url":null,"abstract":"<div><p>We investigated the thermodynamic and quantum-information cost of irreversible information erasure at the event horizon of hairy black holes generated through gravitational decoupling via extended geometric deformation. Starting from the Schwarzschild black-hole seed solution, we considered two families of hairy geometries satisfying the strong and dominant energy conditions. Landauer’s principle was used to relate the minimum energy required to erase one bit of information to the Hawking temperature of the deformed horizon. We derived the corresponding horizon radii, Hawking temperature, Bekenstein–Hawking entropy, and Landauer cost as functions of the gravitational decoupling parameter, the hair length scale, and the effective charge associated with the additional gravitational sector. For the parameter ranges analysed, our results show that gravitational hair tends to reduce the Hawking temperature and the minimum Landauer erasure cost, while simultaneously increasing the horizon area and the Bekenstein–Hawking entropy. The Reeb–Wolf finite-size correction provides an additional positive contribution to the erasure cost, but remains subdominant due to the large effective dimension of the horizon reservoir. We further separated the Reeb–Wolf correction into mutual-information and relative entropy contributions, showing that the former is governed by the area-spacing parameter, whereas the latter is controlled by the actual energy gap between neighbouring horizon levels. Furthermore, the Landauer spectrum obtained by quantising the area decreases as the quantum number associated with the horizon increases, although this variation does not occur in the same way in the SEC and DEC branches.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"GEM detector assembly and characterization facility at Panjab University for CMS and future applications","authors":"Kashish Verma,&nbsp;Vipin Bhatnagar","doi":"10.1140/epjp/s13360-026-08285-1","DOIUrl":"10.1140/epjp/s13360-026-08285-1","url":null,"abstract":"<div><p>The gas electron multiplier (GEM) leverages gas ionization to produce electron ion pairs for particle detection. It is used in the CMS experiment at the LHC to improve muon detection in the forward region, where high precision and radiation resistance are required. We present the assembly and quality control (QC) tests of GEM detector modules carried out at Panjab University, a GEM production site for the CMS experiment. The QC procedures include gas leak tests, high-voltage stability checks, and effective gain measurements, all crucial to ensuring detector reliability and performance before their integration into the system. The GEM has emerged as a highly versatile and radiation-hard gaseous detector, offering excellent spatial resolution and high-rate capability. In addition, GEMs offer operational flexibility, ease of handling, and stable long-term performance, making them highly suitable for the evolving requirements of future high-energy physics experiments. This work contributes to the ongoing use of GEM technology in CMS and highlights its potential for future tracking systems at next-generation colliders.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Synergistic enhancement of copper corrosion protection using Origanum compactum essential oil and Zn2+ cations","authors":"Z. Aribou,&nbsp;I. Saber,&nbsp;M. Galai,&nbsp;M. Tiskar,&nbsp;M. Elhaid,&nbsp;M. Chafiq,&nbsp;Amr Elgendy,&nbsp;M. Ebn Touhami,&nbsp;A. Chaouiki,&nbsp;Nouf M. Alyami,&nbsp;Rafa Almeer","doi":"10.1140/epjp/s13360-026-08336-7","DOIUrl":"10.1140/epjp/s13360-026-08336-7","url":null,"abstract":"<div><p>Metal corrosion poses a major challenge to the long-term reliability and economic sustainability of metallic structures, especially in the automotive, aerospace, and petrochemical industries. In the present work, we introduce a hybrid corrosion inhibition strategy based on the combination of <i>Origanum compactum</i> essential oil and Zn²⁺ for copper protection in 0.5 M H₂SO₄. The originality of this approach lies in exploiting the synergistic interaction between Zn²⁺ and bioactive constituents of the essential oil to enhance adsorption, surface coverage, and copper passivation. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) demonstrated a high inhibition efficiency of 94.5%, confirming the superior performance of our inhibitor. SEM/EDS, AFM, and contact angle measurements further evidenced the formation of a compact, homogeneous, and hydrophobic protective layer on the copper surface. Importantly, advanced quantum chemical calculations were performed to elucidate the synergistic mechanism in order to understand the molecular-level anticorrosion interactions underlying the system. The Density Functional Theory (DFT) results showed that there was a very strong coordination between Zn²⁺ and the principal constituents of the essential oil (thymol, carvacrol, γ-terpinene, and p-cymene), which enhanced adsorption stability and surface coverage. These results demonstrate that combining <i>Origanum compactum</i> essential oil with Zn²⁺ provides an effective and environmentally attractive strategy for copper corrosion protection in acidic media.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Analyzing trade-offs in electron heat engine optimization using the ecological-efficient function","authors":"J. A. Sebastián-García,&nbsp;J. J. Fernández","doi":"10.1140/epjp/s13360-026-08329-6","DOIUrl":"10.1140/epjp/s13360-026-08329-6","url":null,"abstract":"<div><p>We analyze evolutionary transitions between performance criteria for electron heat engines. The transition from power <i>P</i> to efficient power <span>(P_{eta })</span> improves efficiency and also reduces entropy generation, while the transition from ecological function <span>(Omega)</span> to efficient-ecological function <span>(Omega _{eta })</span> achieves a more balanced multi-objective compromise. Through multi-objective optimization using the NSGA-II algorithm, we obtain the four-dimensional Pareto front encompassing <i>P</i>, <span>(P_{eta })</span>, <span>(Omega)</span>, and <span>(Omega _{eta })</span>. The Pareto analysis reveals that the <span>(Omega _{eta })</span>-optimal region concentrates along a central ridge of the frontier where ecological and efficient-power objectives naturally align, confirming its Pareto-efficient nature. Quantitative comparison shows that the <span>(Omega rightarrow Omega _{eta })</span> transition requires a substantial sacrifice of <span>(58.71%)</span> in the ecological function but achieves a significant reduction in entropy generation of <span>(25.10%)</span> and a modest efficiency gain of <span>(3.35%)</span>. In contrast, the <span>(P rightarrow P_{eta })</span> transition sacrifices only <span>(7.91%)</span> of power for a <span>(21.92%)</span> efficiency gain while achieving a <span>(48.55%)</span> reduction in entropy generation. Thus, both pathways reduce entropy, but with different trade-offs. Our results do not establish an absolute superiority of either criterion. Instead, they reveal a design-dependent trade-off: the <span>(P rightarrow P_{eta })</span> pathway is preferable when power output and efficiency are the primary concerns and a narrow operational window is acceptable, as it achieves large efficiency gains (<span>(21.92%)</span>) and entropy reductions (<span>(48.55%)</span>) with minimal power sacrifice (<span>(7.91%)</span>). Conversely, the <span>(Omega rightarrow Omega _{eta })</span> pathway is preferable when operational robustness, design flexibility, and a balanced multi-objective compromise between power, efficiency, and entropy generation are prioritized, despite requiring a much larger sacrifice in its primary objective (<span>(58.71%)</span>). The choice between these pathways thus depends on the specific design priorities and operational constraints of the target application.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Compact object model in F(Q, T) gravity via the minimal geometric deformation approach","authors":"Sat Paul,&nbsp;Jitendra Kumar,&nbsp;S. K. Maurya","doi":"10.1140/epjp/s13360-026-08297-x","DOIUrl":"10.1140/epjp/s13360-026-08297-x","url":null,"abstract":"<div><p>In this work, we develop a model of the compact star EXO 1785-248 within the framework of <i>F</i>(<i>Q</i>, <i>T</i>) gravity in the presence of an electric field, employing the gravitational decoupling technique through the Minimal Geometric Deformation (MGD) approach. The resulting decoupled system of field equations is solved by adopting the Finch–Skea metric, together with the Karmarkar condition and the mimic constraint (<span>(Theta _{1}^{1}=p_{text{r}})</span>). The physical viability of the obtained solutions is thoroughly examined through analyses of the regularity conditions, the equilibrium condition, the causality criterion, and the stability requirements. The results indicate that the combined effects of MGD and the mimic constraint yield realistic, physically acceptable stellar configurations. Consequently, the proposed framework provides a robust and consistent approach to investigating compact stars in <i>F</i>(<i>Q</i>, <i>T</i>) gravity and contributes to a deeper understanding of their structure and physical behaviour within this modified gravitational theory.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Rapid and direct detection of uranium in Al-Najaf soil samples using laser-induced breakdown spectroscopy technology","authors":"Ekhlas Jabir Mahmood","doi":"10.1140/epjp/s13360-026-08355-4","DOIUrl":"10.1140/epjp/s13360-026-08355-4","url":null,"abstract":"<div><p>Methods employed in the analysis of uranium in soil samples that have high complexity are quite expensive and necessitate dangerous chemical treatment. The current research provides an inexpensive method of analysis through the use of LIBS for detecting uranium spectral signatures in 20 surface and 30 cm depth soil samples collected in Al-Najaf governorate, Iraq. The LIBS analysis of the samples was conducted by employing a nanosecond Nd: YAG laser (wavelength 1064 nm) in addition to the NIST atomic data base. The recorded emission spectra covered 161.559 to 898.826 nm, revealing matrix homogeneity in the UV and NIR regions. Relative intensities varied significantly from 0.00257 to 0.923 at 30 cm depth, indicating variations in the observed uranium spectral response among the analyzed samples. The number of identified uranium-associated spectral lines ranged from 5 to 8 per sample. The neutral uranium (U I) line at 358.262 nm appeared consistently across all samples, indicating its potential as a spectral marker for rapid uranium screening. Conversely, a prominent enhancement of the singly ionized (U II) line at 373.339 nm was uniquely observed in surface sample S5 due to localized matrix effects. It is concluded that this work establishes a foundational preliminary spectral library that supports rapid qualitative screening and environmental radiological monitoring in Al-Najaf province.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Confinement induced structural and entropic features of positronic systems","authors":"Koustav D. Chakladar,&nbsp;Santanu Mondal,&nbsp;Jayanta K. Saha","doi":"10.1140/epjp/s13360-026-08287-z","DOIUrl":"10.1140/epjp/s13360-026-08287-z","url":null,"abstract":"<div><p>In this study, we explore various structural and quantum information-theoretic measures of the ground state of <span>(text {Ps}^-)</span> and its subsystem Ps under the influence of pressure-induced spatial confinement within the Ritz variational framework. Various geometrical quantities, such as radial and angular moments, undergo significant modification with the changes in the confinement parameters. Evidently, the annihilation rates for both systems increase as thermodynamic pressure increases in the systems. Further, the quantum entanglement measure, quantified through von Neumann entropy, reveals the possibility of manipulating the entanglement strength in <span>(text {Ps}^-)</span>, including the emergence of a minimally entangled state. Moreover, Shannon and Fisher information entropies demonstrate the localization effects as pressure increases in both systems, along with a pressure-induced quantum similarity measure between the two systems under consideration.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-08287-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"The Penrose process in rotating regular black holes","authors":"Anjan Kar,&nbsp;Ayan Dey,&nbsp;Sayan Kar","doi":"10.1140/epjp/s13360-026-08316-x","DOIUrl":"10.1140/epjp/s13360-026-08316-x","url":null,"abstract":"<div><p>We investigate the Penrose process of energy extraction in the context of rotating regular black holes. Previously known geometries, as well as a new rotating regular black hole generated from a recently proposed (Gen. Rel. Grav. <b>56</b>, 52 (2024)) non-rotating, seed solution are considered in our analysis of energy extraction. For the known Neves–Saa class of rotating regular black hole solutions, which includes the Bardeen, Hayward and Fan–Wang spacetimes as special cases, the extraction efficiency is bounded above by the known value for the singular Kerr spacetime. However, in the case of the new rotating regular black hole, which does not have a Schwarzschild singular limit for zero rotation, the extraction efficiency can indeed become much larger, as evident through our results here. Here too, the highest efficiency occurs for the singular solution. Thus, expectedly, both the regularisation parameter in the metric functions, as well as the character of the seed non-rotating solution influence the extent of energy extraction, relative to the respective singular scenarios.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Correction to: Pseudo-unitary dynamics of free relativistic quantum mechanical twofold systems","authors":"J. G. Cardoso","doi":"10.1140/epjp/s13360-026-08339-4","DOIUrl":"10.1140/epjp/s13360-026-08339-4","url":null,"abstract":"","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}