物理与天体物理最新文献

{"title":"Effective Pressure of the FRW Universe","authors":"Shi-Bei Kong","doi":"10.1016/j.aop.2025.170163","DOIUrl":"10.1016/j.aop.2025.170163","url":null,"abstract":"<div><div>In this paper, we study the effective pressure of the <span><math><mi>N</mi></math></span>-dimensional FRW(Friedmann–Robertson– Walker) universe in Einstein gravity, Gauss–Bonnet gravity, and Lovelock gravity. The effective pressure is defined by <span><math><mrow><msub><mrow><mi>P</mi></mrow><mrow><mi>e</mi><mi>f</mi><mi>f</mi></mrow></msub><mo>≔</mo><mo>−</mo><mi>d</mi><mi>E</mi><mo>/</mo><mi>d</mi><mi>V</mi></mrow></math></span>, where <span><math><mrow><mi>E</mi><mo>=</mo><mi>ρ</mi><mi>V</mi></mrow></math></span> is the effective energy and <span><math><mi>V</mi></math></span> is the volume of the FRW universe inside the apparent horizon. The effective pressure in Einstein gravity is always negative and its absolute value decreases with the horizon radius <span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>A</mi></mrow></msub></math></span>. The effective pressure in Gauss–Bonnet gravity is different with the one in Einstein gravity only when <span><math><mrow><mi>N</mi><mo>≥</mo><mn>6</mn></mrow></math></span>, and in this case, the effective pressure is not always negative and has a minimum, which is very similar to the potential between molecules. The effective pressure in Lovelock gravity can have multiple zero-points and extreme points. The effective pressure in different dimensions has interesting relations. We also find that under certain condition, the effective pressure is equivalent with the ‘ordinary’ pressure <span><math><mi>p</mi></math></span> of the perfect fluid, and this condition do not depend on the specific choice of gravitational theories.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"481 ","pages":"Article 170163"},"PeriodicalIF":3.0,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144757234","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":"Multi-parameter optimization of structural noise from railway composite bridge based on response surface methodology and genetic algorithm","authors":"Xiaozhen Li,&nbsp;Di Wu,&nbsp;Xihao Jiang,&nbsp;Yao Yuan,&nbsp;Zhichao Yang","doi":"10.1016/j.apacoust.2025.110973","DOIUrl":"10.1016/j.apacoust.2025.110973","url":null,"abstract":"<div><div>The accelerated deployment of China’s high-speed rail infrastructure has raised acoustic challenges associated with steel–concrete composite (SCC) bridges, which exhibit enhanced structural-borne noise emissions compared to monolithic concrete counterparts. This research systematically explores vibro-acoustic coupling mechanisms in SCC bridges and develops a multi-criteria design optimization framework targeting noise mitigation. Field-test-validated numerical simulations integrating finite element–boundary element (FE-BE) analysis (20–200 Hz) and statistical energy analysis (SEA) (200–2000 Hz) were established to predict vibration transmission and acoustic radiation patterns. Experimental validation focused on a three-span continuous SCC bridge with span lengths of (32 + 40 + 32) m. Acoustic contribution analysis reveals that the concrete deck dominates low-frequency noise (43.2–44.7 % contribution), while the steel I-beam web significantly influences mid-to-high frequencies (32.6–34.3 % contribution). Three critical design parameters—concrete deck thickness, steel web thickness, and diaphragm thickness are optimized using response surface methodology (RSM) and the genetic algorithm (GA), constrained by mass (&lt;115 % original) and natural frequency (85–105 % original). Optimization reduces the overall sound pressure level by 1.93 dB(A), achieving 84.22 dB(A) at the critical field point. The results demonstrate that coordinated increases in deck and web thicknesses yield optimal noise reduction while balancing structural and economic requirements. This work provides a systematic framework for the acoustic design of SCC bridges, offering practical insights for noise control in high-speed rail infrastructure.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"240 ","pages":"Article 110973"},"PeriodicalIF":3.4,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Extremely Low‐Turn‐On‐Voltage Enabled Uniformity for Large‐Area Smart Window to Manipulate Solar Radiation","authors":"Xin Tang, Xin Hu, Long Yuan, Yu Duan","doi":"10.1002/lpor.202501157","DOIUrl":"https://doi.org/10.1002/lpor.202501157","url":null,"abstract":"Electro‐reflective devices (ERDs) show high energy efficiency as smart windows for the next generation of buildings and electric vehicles. However, the un‐uniformly distributed electric field between the electrode layers in ERDs results in poor deposition uniformity, sluggish response rate, and short cyclability. Herein, TBAP molecules are used to form a network of weakly polymerized gel molecules and weaken the effect of the voltage drop on the electrodeposited silver uniformity, and the device is optimized in terms of the turn‐on voltage (from −1.67 down to −1.47 V), the response rate (improved by 22%) and coloring uniformity (improved from 48.8% to 25.6%), and maintaining optical contrast (82% in 700 nm) and IR reflectance (80%). The 625 cm<jats:sup>2</jats:sup> ERDs are produced and achieved a rapid response within 135 s. In addition, outdoor tests show that the ERDs have excellent photo‐thermal modulation. Therefore, this work provides a fundamental design idea for the development of rapid‐response large‐area electro‐reflective smart windows.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"60 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144747144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Microwave-regime demonstration of plasmonic non-reciprocity in a flowing two-dimensional electron gas","authors":"Jingyee Chee, Han Sae Jung, Shannon Harvey, Kenneth West, Loren Pfeiffer, Amir Yacoby, Donhee Ham","doi":"10.1063/5.0264193","DOIUrl":"https://doi.org/10.1063/5.0264193","url":null,"abstract":"The speed of a plasmonic wave in the presence of electron drift in a conductor depends on the wave's propagation direction, with the wave traveling along the drift (“forward wave”) faster than the wave traveling against the drift (“backward wave”). Phenomena related to this plasmonic non-reciprocity—which is relatively more pronounced in two-dimensional conductors than in bulk conductors and could lead to solid-state device applications—have been studied in THz and optical spectral regimes. Here, we demonstrate the plasmonic non-reciprocity at microwave frequencies (10–50 GHz). Concretely, we conduct, at 4 K, a microwave network analysis on a gated GaAs two-dimensional electron gas with electron drift (i.e., DC), directly measuring the forward and backward wave speeds via their propagation phase delays. We resolve, for example, forward and backward wave speeds of 4.26×10−3±8.97×10−6 (normalized to the speed of light). Sufficient consistency between the electron drift speed obtained from the microwave measurement and that alternatively estimated by a DC transport theory further confirms the non-reciprocity. We conclude this paper with a discussion on how to enhance the non-reciprocity for real-world applications, where degeneracy pressure would play an important role.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"8 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144747644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Fokker–Planck equation for the Brownian motion in the post-Newtonian approximation","authors":"Gilberto M. Kremer","doi":"10.1016/j.aop.2025.170153","DOIUrl":"10.1016/j.aop.2025.170153","url":null,"abstract":"<div><div>A mixture of light-gas particles and Brownian heavy particles is analyzed within the framework of a post-Newtonian Boltzmann equation to determine the Fokker–Planck equation for the Brownian motion. For each species, the equilibrium distribution function refers to the corresponding post-Newtonian Maxwell–Jüttner distribution function. The expressions for the friction viscous coefficient in the first and second post-Newtonian approximations are determined, and we show their dependence on the corresponding gravitational potentials. A linear stability analysis in the Newtonian and post-Newtonian Fokker–Planck equations for the Brownian motion is developed, where the perturbations are assumed to be plane harmonic waves of small amplitudes. From a dispersion relation it follows that: (i) for perturbation wavelengths smaller than the Jeans wavelength two propagating modes – corresponding to harmonic waves in opposite directions – and one mode that does not propagate show up; (ii) for perturbation wavelengths bigger than the Jeans wavelength the time evolution of the perturbation corresponds to a growth or a decay and the one which grows refers to the instability.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"481 ","pages":"Article 170153"},"PeriodicalIF":3.0,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144748786","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":"Hyperfine mass splittings in ground and radially excited states of heavy-flavored QQQ¯Q¯ tetraquarks: PGM defect and fractional order effects","authors":"D. Nga Ongodo ,&nbsp;A.A. Atangana Likéné ,&nbsp;J.M. Ema'a Ema'a ,&nbsp;P. Ele Abiama ,&nbsp;G.H. Ben-Bolie","doi":"10.1016/j.nuclphysa.2025.123215","DOIUrl":"10.1016/j.nuclphysa.2025.123215","url":null,"abstract":"&lt;div&gt;&lt;div&gt;In this study, we investigate the masses and fall-apart decays of the radial excitations in &lt;span&gt;&lt;math&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;/math&gt;&lt;/span&gt; tetraquarks using a framework that incorporates topological defects and fractional-order derivatives via the generalized conformable fractional formalism. The interaction potential combines the Cornell potential with harmonic oscillator and inversely quadratic terms, adapted for diquark configurations. The Hamiltonian includes spin-independent and spin-dependent components, with the latter breaking degeneracies between spin singlets and triplets. The Schrödinger equation is solved analytically using the generalized fractional Nikiforov-Uvarov method. Our analysis focuses on axial-vector diquarks in the ground (&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;) and first radially excited states (&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;), ensuring compliance with symmetry principles. The computed diquark and tetraquark masses, for states with &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;J&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;P&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;, align well with existing results, with deviations within reasonable ranges. Incremental differences observed in our models with varying &lt;em&gt;δ&lt;/em&gt; values highlight the influence and adaptability of the fractional parameter, providing insights into the modeling approach. Heavy tetraquark states should be broad and difficult to detect experimentally. However, for some first radially excited states, we have calculated masses below their corresponding two-meson thresholds, indicating stability against fall-apart decays, while others with masses above these thresholds are likely to decay rapidly. The enhanced stability of lower-mass states increases their chances of experimental observation, as ongoing accelerator experiments search for exotic hadrons. Additionally, it is found that the &lt;span&gt;&lt;math&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;6400&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;6600&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; structures observed by ATLAS in the di-&lt;span&gt;&lt;math&gt;&lt;mi&gt;J&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;ψ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; invariant mass spectrum can be attributed to the &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;m","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1063 ","pages":"Article 123215"},"PeriodicalIF":2.5,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749846","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":"Incoherent and coherent random lasing in electrospun fiber-embedded glass microtube systems with different sizes","authors":"Jiatao Hu ,&nbsp;Jiamin Yin ,&nbsp;Yuxia Zhao ,&nbsp;Yining Zhang ,&nbsp;Hao Lv ,&nbsp;Shuaiyi Zhang ,&nbsp;Xia Wang","doi":"10.1016/j.optcom.2025.132281","DOIUrl":"10.1016/j.optcom.2025.132281","url":null,"abstract":"<div><div>Random lasers (RLs), characterized by their utilization of disordered scattering media for optical feedback, offer unique benefits such as reduced spatial coherence and inherent speckle suppression. These attributes make them promising candidates for imaging and display technologies. However, the efficient achievement of coherence tunable RL in a restrained system remains a challenge in this field. In this study, we introduce a microtube-based RL system, which comprises gold nanoparticle (Au NP)-doped DCJTB dye embedded within electrospun fiber networks, and systematically examine the interaction between geometric constraints and lasing performance. The results reveal a marked dependence of the lasing threshold and coherence on microtube dimensions. A thick tube (1.3 mm diameter, 0.5 cm length) displayed incoherent emission with a high threshold of 355 μJ/Pulse, while a thin tube (1.0 mm diameter) generated coherent RL at a significantly lower threshold of 26 μJ/Pulse, which is only 7.3 % of the threshold of the thick tube. This notable disparity is attributed to the increased photon scattering efficiency and feedback mechanisms within the confined geometry of the thin tube, which optimize the effective cavity path length and amplify gain-to-loss ratios. Further investigations on thin-tube systems of varying lengths (0.5–1.5 cm) show a steady increase in threshold (26–37 μJ/Pulse) with the extension of tube length, directly linked to the reduced geometric confinement and weakened feedback effects. Furthermore, we confirm the practical application of the thin-tube RL as a compact, high-fidelity light source for speckle-free imaging, achieving speckle contrast values as low as 0.0665. These findings show the transformative potential of geometrically optimized microtube RL systems in advancing low-energy, high-resolution optical technologies for biomedical imaging and next-generation display applications.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"592 ","pages":"Article 132281"},"PeriodicalIF":2.5,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144757746","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":"Connecting extended Wigner’s friend arguments and noncontextuality","authors":"Laurens Walleghem, Yìlè Yīng, Rafael Wagner, David Schmid","doi":"10.22331/q-2025-07-31-1819","DOIUrl":"https://doi.org/10.22331/q-2025-07-31-1819","url":null,"abstract":"The Local Friendliness argument is an extended Wigner's friend no-go theorem that provides strong constraints on the nature of reality – stronger even than those imposed by Bell's theorem or by noncontextuality arguments. In this work, we prove a variety of connections between Local Friendliness scenarios and Kochen-Specker noncontextuality. Specifically, we first show how one can derive new Local Friendliness inequalities using known tools and results from the literature on Kochen-Specker noncontextuality. In doing so, we provide a new derivation for some of the facets of the Local Friendliness polytope, and we prove that this polytope is equal to the Bell polytope in a wide range of extended Wigner's friend scenarios with multipartite agents and sequential measurements. We then show how any possibilistic Kochen-Specker argument can be mathematically translated into a related proof of the Local Friendliness no-go theorem. In particular, we construct a novel kind of Local Friendliness scenario where a friend implements several compatible measurements (or joint measurements of these) in between the superobserver's operations on them. We illustrate this with the well-known 5-cycle and Peres-Mermin contextuality arguments.","PeriodicalId":20807,"journal":{"name":"Quantum","volume":"27 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144747619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 parameter space of hierarchical triple black hole systems","authors":"M. Attia, Y. Sibony","doi":"10.1051/0004-6361/202555165","DOIUrl":"https://doi.org/10.1051/0004-6361/202555165","url":null,"abstract":"We present a comprehensive exploration of hierarchical triple black hole (BH) systems to address the long-standing “initial separation” problem in gravitational wave (GW) astrophysics. This problem arises because isolated BH binaries must have extremely small initial separations to merge within a Hubble time via GW emission alone, separations at which their stellar progenitors would have merged prematurely. Using a modified version of the JADE secular code that incorporates GW energy loss, we systematically investigate a seven-dimensional parameter space consisting of the masses of the three BHs (5 − 100 <i>M<i/><sub>⊙<sub/> for the inner binary components, 1 − 200 <i>M<i/><sub>⊙<sub/> for the tertiary), inner and outer semimajor axes (1 − 200 AU and 100 − 10 000 AU, respectively), outer orbit eccentricity (0 − 0.9), and mutual inclination between orbits (40° −80°). We employed an innovative adaptive Markov chain Monte Carlo approach that preferentially samples the transition boundary between merging and nonmerging configurations, allowing us to efficiently map the merger probability landscape with nearly 15 million distinct simulations. Our results reveal that the parameter space regions most conducive to mergers correspond to systems with asymmetric inner binary masses, large inner separations where the von Zeipel–Lidov–Kozai (ZLK) mechanism can operate effectively without being suppressed by relativistic precession, small outer separations providing stronger perturbations, and large outer eccentricities that bring the tertiary closer at pericenter. Merger probability is also globally positively correlated with mutual inclination, with some irregular features departing from monotonicity. For nonmerging systems, we developed a classification scheme based on the presence of GW emission and ZLK oscillations, identifying distinct regions in parameter space for each category and providing a better understanding of the hierarchical triple channel. Additionally, we trained a neural network that predicts merger outcomes with an area under the receiver operating characteristic (ROC) curve score of 99% and an overall accuracy of 95%, increasing to 99.7% accuracy for the ∼80% of predictions made with high confidence. This model enables rapid population synthesis studies without requiring computationally expensive dynamical simulations. We validated our secular approach through comparison with direct <i>N<i/>-body integrations for select systems, finding good qualitative agreement in merger outcomes for 87% of test cases, confirming that our methodology effectively captures the essential dynamics governing triple BH evolution, while enabling exploration at an unprecedented scale. Our results provide crucial insights into which configurations of hierarchical triples can resolve the initial separation problem and can serve as viable progenitors for the growing catalog of GW detections.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"37 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144747620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Enhancing the acoustic performance of eucalyptus and poplar wood via ammonium persulfate treatment: Structural and functional insights","authors":"Batol Masruri ,&nbsp;Ali Khavanin ,&nbsp;Ebrahim Taban ,&nbsp;Somayeh Amininasab","doi":"10.1016/j.apacoust.2025.110983","DOIUrl":"10.1016/j.apacoust.2025.110983","url":null,"abstract":"<div><div>This study investigates the structural and acoustic enhancements of eucalyptus and poplar wood following ammonium persulfate (APS) treatment, aiming to develop sustainable and high-performance sound-absorbing materials. A statistically optimized approach was applied using Response Surface Methodology (RSM) combined with Central Composite Design (CCD) to determine the optimal APS concentration (2–8 wt%) and treatment duration (4–12 h) for maximizing the Sound Absorption Average (SAA). Under optimal conditions (5 wt% APS, 8 h), SAA increased significantly by 147.73 % in eucalyptus and 73.54 % in poplar compared to untreated samples. Fourier Transform Infrared Spectroscopy (FTIR) revealed reductions in lignin and hemicellulose, enhanced porosity, and increased carboxyl group formation, while X-ray Diffraction (XRD) confirmed greater crystallinity without altering the cellulose I structure. Field Emission Scanning Electron Microscopy (FESEM) revealed significant microstructural changes, including increased surface roughness and pore formation, contributing to improved sound absorption. Additionally, transmission loss (TL) measurements indicated that APS treatment enhanced sound insulation performance, particularly at mid-to-high frequencies, with the highest TL values recorded at 3150 Hz for eucalyptus (17.33 dB) and 4000 Hz for poplar (19.37 dB). Experimental validation under optimal conditions showed minimal deviation from predicted results, confirming the model’s reliability. Collectively, these findings establish APS treatment as a scalable and effective method for enhancing the structural and acoustic performance of wood, highlighting its potential for sustainable acoustic applications.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"240 ","pages":"Article 110983"},"PeriodicalIF":3.4,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}