The European Physical Journal Plus最新文献

{"title":"First-principles calculations to investigate structural and electronic properties of transition metal-embedded modified 5,10,15,20-tetrakis(pentafluorophenyl) porphyrins","authors":"Zhi Li,&nbsp;Jia-Qi Jiang,&nbsp;Yao-hui Hu","doi":"10.1140/epjp/s13360-026-08529-0","DOIUrl":"10.1140/epjp/s13360-026-08529-0","url":null,"abstract":"<div><p>5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (TPPF₂₀, chemical formula C₄₄H₈N₄F₂₀) demonstrates excellent photostability and oxidative stability. The substitution of nitrogen atoms in macrocycle with C, O, or S can significantly impact the synthetic feasibility and stability of the macrocyclic structure. In this study, the structures, stability, and electronic properties of transition metal (TM) embedded C₄₄H₈N₄F₂₀ and its derivatives have been systematically investigated using density functional theory. The results indicate that the S atom in TMC₄₄H₈N₃SF₂₀ deviates significantly from the central plane of the macrocycle. The overall structural stability of TMC₄₄H₈N₄F₂₀ and its derivatives follows the descending order: TMC₄₅H₈N₃F₂₀&gt; TMC₄₄H₈N₄F₂₀ &gt; TMC₄₄H₈N₃OF₂₀ &gt; TMC₄₄H₈N₃SF₂₀. Additionally, TMC₄₄H₈N₃OF₂₀ exhibits a larger dipole moment than TMC₄₄H₈N₃SF₂₀. Notably, CrC₄₄H₈N₄F₂₀ and CrC₄₄H₈N₃SF₂₀ are expected to possess outstanding electrocatalytic performance and unique catalytic selectivity. Analysis of reactive sites reveals that electrophilic regions are exclusively localized at the C-substituted position in TMC₄₅H₈N₃F₂₀. Furthermore, the Mulliken charges of the TM atoms in TMC₄₄H₈N₃SF₂₀ are slightly lower than those in TMC₄₄H₈N₄F₂₀ and other derivatives, with the exception of CuC₄₅H₈N₃F₂₀ and ZnC₄₅H₈N₃F₂₀.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338772","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":"Roles of polarization and detuning in the noise-induced relaxation dynamics of atomic-molecular bose condensates","authors":"Avinaba Mukherjee,&nbsp;Raka Dasgupta","doi":"10.1140/epjp/s13360-026-08466-y","DOIUrl":"10.1140/epjp/s13360-026-08466-y","url":null,"abstract":"<div><p>We study the relaxation dynamics of a resonant Bose gas driven by Gaussian white noise. The system is characterized by the population imbalance between molecules and atoms as well as their mutual coherence. We analyze longitudinal and transverse relaxation times using mean-field theory and a Bogoliubov–Born–Green–Kirkwood–Yvon hierarchy that incorporates higher-order correlations. We find that when the initial imbalance is near the system equilibrium, that enhances the longitudinal relaxation time, as reflected by a minimum in the drift speed near equilibrium. With an increasing value of initial polarization, the transverse relaxation time is suppressed, evidenced by a reduction in the von Neumann entropy due to coherence loss. As the Feshbach detuning is varied, the longitudinal relaxation time attains a minimum near resonance, where atom–molecule conversion is maximal. In contrast, the transverse relaxation time reaches a maximum near resonance, corresponding to maximal condensate coherence.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338643","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":"Spray-time-dependent deposition of laser-ablated silver nanoparticles on porous silicon enhancing selective green-to-yellow optical response","authors":"Nasih Hma Salah,&nbsp;Mohammed Idrees Omer","doi":"10.1140/epjp/s13360-026-08493-9","DOIUrl":"10.1140/epjp/s13360-026-08493-9","url":null,"abstract":"<div><p>Engineering and developing cost-effective, wavelength-selective photodetectors (PDs) with high responsivity and long-term stability remains a critical challenge in optoelectronics. In this work, we presented a scalable strategy for engineering porous silicon (PS) PDs functionalized with femtosecond-laser-ablated silver nanoparticles (Ag-NPs) using a spray-time-controlled deposition approach. Ag-NPs exhibited strong colloidal stability with a negative surface charge of − 35 mV by zeta potential, and deposited onto PS using optimized spray durations of 250 s (PS- Ag₁-NPs) and 350 s (PS- Ag₂-NPs). FESEM analysis revealed that Ag incorporation induced a clear size-dependent evolution (13.97 nm for PS- Ag₁-NPs and 19.83 nm for PS- Ag₂-NPs) and increased PS layer thickness from 2.27 to 2.65 µm and 2.78 µm, respectively. XRD and FTIR confirmed SiO₂ and AgO formation, with intensities rising with Ag content. Graphite electrodes provided stable ohmic contacts, with thermal annealing at 130 °C for 30 min further improving adhesion and stability. Voltage-dependent I-V characteristics were recorded from 0–5.2 V for all devices, followed by wavelength-resolved photocurrent measurements across the UV-Red spectrum at 2.8, 4.0, and 5.2 V. Ag functionalization substantially reconfigured the spectral response: Under 5.2 V bias, PS- Ag₁-NPs PD exhibited a peak response in the green region (530 nm, 1.7 mW/cm²), achieved a sensitivity of 310.07% and a responsivity of 0.484 A/W, meanwhile, the PS- Ag₂-NPs PD reached its maximum response in the yellow region (575 nm, 2.1 mW/cm²), with 332.40% sensitivity and 0.566 A/W responsivity, outperforming unmodified PS PD (264.62%, 0.106 A/W). Devices demonstrated excellent repeatability (&lt; 9.78% variation) and retained over 91% sensitivity after 60 days. This work demonstrated that spray-time-controlled Ag-NP engineering enabled high-responsivity and long-lived PDs with wavelength-selective performance suitable for advanced optoelectronic applications.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338442","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":"Probing geometrically perturbed strange stars with minimal decoupling using millisecond pulsar timing observations","authors":"Ksh. Newton Singh,&nbsp;S. K. Maurya,&nbsp;A. Errehymy,&nbsp;A. Altaibayeva,&nbsp;J. Rayimbaev,&nbsp;M. Matyoqubov","doi":"10.1140/epjp/s13360-026-08439-1","DOIUrl":"10.1140/epjp/s13360-026-08439-1","url":null,"abstract":"<div><p>We construct a gravitationally decoupled anisotropic strange star model using the minimal geometric deformation approach with a MIT bag equation of state and an additional source sector controlled by a deformation parameter <span>(beta)</span> and a radial perturbation scale <span>(Psi)</span> through <span>(g(r)=sin (Psi r^{2}))</span>. The resulting Einstein system is consistently split into seed and <span>(theta)</span>-sectors and matched to an exterior Schwarzschild geometry. The model is constrained by high-mass pulsars: PSR J0740+6620 <span>((2.08pm 0.07,M_odot ))</span>, PSR J1810+1744 <span>((2.13pm 0.04,M_odot ))</span>, PSR J1959+2048 <span>((2.18pm 0.09,M_odot ))</span>, and PSR J2215+5135 <span>((2.28^{+0.10}_{-0.09},M_odot ))</span>. It reproduces these objects with predicted radii <span>(R approx 11.3)</span>–12.9 km. The maximum mass reaches <span>(M_{max } approx 2.28,M_odot)</span> for <span>(beta = 3times 10^{-3})</span> and <span>(Psi approx 0.03,text {km}^{-2})</span>, while for <span>(beta = 10^{-3})</span> the configuration yields <span>(M_{max } approx 2.12,M_odot)</span> with <span>(R approx 12.2)</span> km. The central density lies in <span>(rho _0 approx (2.4)</span>–<span>(3.1)times 10^{-4},text {km}^{-2})</span>, decreasing smoothly to <span>(rho _s approx 2.0times 10^{-4},text {km}^{-2})</span>. The anisotropy increases from zero at the center to <span>(Delta approx (0.25)</span>–<span>(0.45)times 10^{-4},text {km}^{-2})</span> near the surface, generating additional outward support that enhances compactness by <span>(sim 15%)</span>. The compactness parameter spans <span>(C approx 0.17)</span>–0.22, safely below the Buchdahl limit, while the surface redshift reaches <span>(z_s approx 0.25)</span>–0.38. The radial and tangential sound speeds remain causal, with <span>(v_r^{2} approx 0.25)</span>–0.65 and <span>(v_t^{2})</span> rising to <span>(approx 0.84)</span> under strong perturbations. The adiabatic index varies within <span>(Gamma approx 1.35)</span>–2.10, approaching the relativistic threshold near the core while remaining stable overall. The condition <span>(dM/drho _0 &gt; 0)</span> is satisfied throughout, confirming dynamical stability. Overall, <span>(beta)</span> enhances the maximum mass by up to <span>(sim 15%)</span>, while <span>(Psi)</span> introduces controlled oscillatory structure without violating observational constraints, producing stable ultra-compact stars consistent with current pulsar data. We also compute the tidal Love number <span>(k_2)</span> and the dimensionless tidal deformability <span>(Lambda)</span>, finding that the canonical <span>(1.4,M_odot)</span> configuration satisfies the GW170817 constraint <span>(70&lt; Lambda _{1.4} &lt; 580)</span> for all physically admissible values of <span>(beta)</span> and <span>(Psi)</span>.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338268","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":"Hybrid machine learning and process simulation framework for conversion of CO2 to propane","authors":"Debadutta Patra,&nbsp;Mrunmay Mayuresh Joshi,&nbsp;Ommkar Prasad Das,&nbsp;B. G. Rohan Krishna","doi":"10.1140/epjp/s13360-026-08470-2","DOIUrl":"10.1140/epjp/s13360-026-08470-2","url":null,"abstract":"<div><p>This study presents machine-learning-guided screening of 40 catalyst formulations for the hydrogenation of CO₂ to propane, spanning platinum-group metals, chromium oxides, transition metals, and bimetallic combinations across 450–625 °C and 0.1–0.5 MPa, as a greenhouse-gas mitigation strategy yielding a versatile fuel for gas cutting and liquefied petroleum gas (LPG) blending. CO₂ conversion ranged 8.1–19.5% and propane selectivity from 76.9 to 96.8%, alongside a dimensionless Catalyst Ranking Index (CRI; maximum value 88). A random-forest model trained on temperature, pressure, catalyst loading, reaction time, and space velocity predicted CO₂ conversion and propane selectivity with fivefold cross-validated <i>R</i>² of 0.70 and 0.47, and separated industrially viable formulations with 75 ± 12% cross-validated accuracy against a 60% majority-class baseline. Chromium oxide catalysts showed higher CO₂ conversion across the four catalyst families (one-way ANOVA, <i>F</i>(3,36) = 4.4, <i>p </i>= 0.0096, η²≈ 0.27; <i>n </i>= 5, so indicative), whereas the propane-selectivity difference was not significant in the primary comparison (<i>p </i>= 0.90) and is sensitive to the family assignment. A base-case Aspen Plus flowsheet, whose fixed-yield (RYIELD) reactor block was later found not to conserve elemental carbon and hydrogen and whose separators are flash/component-splitter blocks with specified split fractions, gave a top-product propane purity of 93.6 mass %; this is a splitter-fraction target rather than a converged column result. A separate kinetic recycle model, solved outside Aspen Plus and not yet reconverged within it, gave 92.4 mass %. Together, this machine-learning-assisted catalyst screening, statistical family comparison, and Aspen Plus process modelling illustrate a workflow, demonstrated here only for CO₂-to-propane screening; its transfer to other CO₂-hydrogenation products (e.g. methanol or higher alcohols) was not tested in this work.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338443","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":"Constraining anisotropic f(R) cosmologies through observational data analysis","authors":"Shraddha Joshi,&nbsp;Shailendra D. Deo,&nbsp;Mayur Mune,&nbsp;Safiqul Islam,&nbsp;Praveen Kumar Dhankar","doi":"10.1140/epjp/s13360-026-08512-9","DOIUrl":"10.1140/epjp/s13360-026-08512-9","url":null,"abstract":"<div><p>The present study explores the cosmological dynamics of an LRS Bianchi Type-I universe in the context of <i>f</i>(<i>R</i>) gravity, focusing on vacuum solutions. Two anisotropic models are constructed by considering different functional forms of <i>f</i>(<i>R</i>), where plane-symmetric LRSBI metrics incorporate anisotropy in the expansion rates, maintaining directional differences among Hubble parameters and scale factors throughout cosmic evolution. While such anisotropic assumptions in general relativity typically lead to a decelerating universe, functional forms of <i>f</i>(<i>R</i>) can support both accelerating and decelerating expansion branches, depending on the corresponding model parameters. To constrain the model parameters, we perform a comprehensive statistical analysis using Markov chain Monte Carlo (MCMC) methods with Hubble, BAO, and Pantheon datasets. The resulting observational constraints are interpreted at the level of the effective mean-background expansion. Model I and II constraints are illustrated through posterior contour and error bar plot, and the corresponding statistical values are summarized in tables.\u0000</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-08512-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338441","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":"Charge dependence of cusp formation in a phenomenological KZ-type black-hole metric","authors":"G. G. L. Nashed","doi":"10.1140/epjp/s13360-026-08464-0","DOIUrl":"10.1140/epjp/s13360-026-08464-0","url":null,"abstract":"<div><p>We examine the equatorial capture shadow of a phenomenological charged Konoplya–Zhidenko-type metric with <span>(Delta =r^2+a^2-2Mr+Q^2-epsilon /r)</span>. The charge term is introduced in Kerr–Newman form; no field-equation derivation is asserted. Using unstable spherical photon orbits that satisfy angular admissibility and the full radial-capture condition, we calculate contacts of projected orbit images. For the theoretical benchmark <span>((a/M,epsilon /M^3)=(2,0.5))</span>, the cusp-removal contact reaches the celestial axis at <span>(Q_{textrm{off}}/Msimeq 1.3520)</span>. A sampling of spin and deformation values shows how this contact charge varies within the ansatz. In the moderate-spin family <span>((a/M,epsilon /M^3)=(0.9,0.5))</span>, the shadow is smooth over <span>(0le Q/Mle 0.6)</span>, develops a cusp near <span>(Q/M=0.9518)</span>, and loses it near <span>(Q/M=1.3313)</span>. The cusp morphology therefore depends on the chosen parameter family; the values are theoretical controls, not observational constraints.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-08464-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338444","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":"Radiological assessment of hookah charcoal and associated lifetime cancer risk from inhalation exposure","authors":"Ahmed N. Hmood,&nbsp;Ahmed Sadeq Musa,&nbsp;Hayder J. Musa","doi":"10.1140/epjp/s13360-026-08505-8","DOIUrl":"10.1140/epjp/s13360-026-08505-8","url":null,"abstract":"<div><p>Despite the widespread use of hookah charcoal, information regarding the radiological hazards associated with its combustion products remains limited. Ten commercially available hookah charcoal samples were analyzed using gamma-ray spectroscopy to determine the activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K. Several radiological parameters, including radium equivalent activity, annual effective dose, inhalation dose, excess lifetime cancer risk, hazard indices, and gamma radiation index, were subsequently evaluated. The mean activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁶K were 19.67, 16.63, and 476.2 <span>(text{B}text{q}.{text{K}text{g}}^{-1})</span>, respectively. The mean annual effective dose from external exposure (AEDE) was 0.048 mSv·year⁻¹, which is lower than the worldwide average value of 0.48 mSv·year⁻¹. In contrast, the mean annual effective inhalation dose (<span>({text{AEDE}}_{text{i}text{n}text{h}})</span>) was 0.221 mSv·year⁻¹, corresponding to a mean excess lifetime cancer risk (ELCR) of <span>(0.77times {10}^{-3})</span>. This is approximately 2.7 times the reference value of 2.9 × 10⁻⁴. This value was found to be lower than the recommended reference levels, with 7 of 9 quantifiable samples analyzed exceeding this value. All calculated hazard indices were below unity, except for one sample that exhibited a gamma radiation index (<span>({I}_{gamma r})</span>) value of 1.239. Calculated external radiation indices were generally low, whereas inhalation contributed more significantly to the estimated internal dose under the assumed exposure scenario. ELCR results indicate an elevated estimated lifetime cancer risk compared to the reference value for natural radiation sources. The fact that the (<i>I</i>_<i>γr</i>) value exceeded unity in one sample warrants further investigation. Additionally, further studies should be conducted to characterize the transfer of radionuclides to airborne particles during charcoal combustion to better assess inhalation exposure under realistic hookah usage conditions.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338391","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":"UV photodetection and self-powered operation of an Au/Thorin/p-Si hybrid Schottky photodiode","authors":"Ali Rıza Deniz,&nbsp;Musa Erdoğan,&nbsp;Zakir Çaldıran,&nbsp;Gökhan Gök","doi":"10.1140/epjp/s13360-026-08521-8","DOIUrl":"10.1140/epjp/s13360-026-08521-8","url":null,"abstract":"<div><p>An Au/Thorin/p-Si/Al hybrid photodiode was fabricated and systematically investigated for UV photodetection. The Thorin (C₁₆H₁₁AsN₂Na₂O₁₀S₂) interlayer was deposited on p-Si by spin coating. SEM, AFM, and XRD analyses revealed a nanocrystalline film with a relatively rough surface morphology. UV–Vis measurements yielded an optical band gap of approximately 2.95 eV, providing insight into the optical characteristics of the Thorin interlayer. Current–voltage characteristics were measured at illumination intensities of 0–100 mW cm⁻², and the main diode parameters were determined using thermionic-emission and Norde methods. The extracted ideality factor increased from 1.55 under dark conditions to 2.41 at the highest illumination intensity, indicating significant deviations from ideal thermionic emission behavior. The photocurrent followed a slightly superlinear power-law dependence on illumination intensity, with α ≈ 1.18, while the photosensitivity exponent β ≈ 1.18 reflected a similar intensity-dependent trend without uniquely identifying the underlying transport mechanism. The device exhibited its strongest measured wavelength-dependent response at 365 nm, with a responsivity of approximately 0.08 A W⁻¹ and an estimated specific detectivity of approximately 2 × 10¹⁰ Jones, calculated using a dark-current-based shot-noise-limited approximation under the reported measurement conditions. Responsivity, specific detectivity, and ON/OFF ratio increased with reverse bias, demonstrating bias-dependent photodetection characteristics. A finite zero-bias photocurrent indicated the capability for self-powered photodetection. Furthermore, the device retained its photoresponse after 30 days, with relatively limited changes in its measured characteristics. Although its responsivity and detectivity remain below those of several recently reported UV photodetectors, the results demonstrate the feasibility of incorporating Thorin as a chemically distinct organic interlayer in silicon-based UV photodiodes.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338390","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":"Truncated Kiselev environments around black holes: selection rules and a lensing–emission consistency relation","authors":"K. R. Thippeswamy,&nbsp;Laxmi Nirani,&nbsp;S. K. Narasimhamurthy","doi":"10.1140/epjp/s13360-026-08479-7","DOIUrl":"10.1140/epjp/s13360-026-08479-7","url":null,"abstract":"<div><p>Kiselev-type anisotropic fluids are a standard analytic model of black holes embedded in dark matter or dark energy, but for the dark-sector range of the Kiselev parameter (<span>(wle 0)</span>), their matter extends to infinity with a divergent ADM mass, so the mass parameters of the metric cannot be tied to the mass a distant observer measures. We remove this obstruction with the <i>truncated Kiselev</i> (TK) geometry, whose dimensionless density <span>(sigma (r)=4pi r^{2}rho)</span> has a spike-like power-law core of index <span>(alpha)</span> and a truncation index <span>(beta)</span> that reproduces the NFW-to-Hernquist range of halo fall-offs. We show that <span>(p_{r}=-rho)</span> is not an extra assumption but the condition for a single-function metric and for a regular non-degenerate horizon when the fluid reaches it. On <span>(alpha &gt;0)</span>, <span>(1&lt;alpha +beta le 2)</span>, <span>(xi ge 1)</span>, <span>(sigma _{H}&lt;1/2)</span> all four energy conditions hold, the ADM mass is finite, the horizon sits at <span>(r=2M)</span> and the Smarr relation closes. We prove three <i>selection rules</i>: to first order in <span>(sigma)</span> the critical curve measures only the Misner–Sharp mass inside the photon sphere, the radiative efficiency only the local density at the ISCO, and the strong-deflection coefficient only <span>(rho +p_{t})</span> at the photon sphere. These yield a mass-independent lensing–emission consistency relation and a dominant-energy bound <span>(mathfrak {a}le 15,mathfrak {b})</span>. A first-order slow-rotation extension with a zero-angular-momentum environment leaves the shadow size unchanged at <i>O</i>(<i>J</i>) and relaxes the bound to <span>(mathfrak {a}le 15,mathfrak {b}+0.238,J/M^{2})</span>. Treating M87* and Sgr A* separately, the Sgr A* shadow with independent mass and distance bounds the mass fraction outside the photon sphere to <span>(F_{textrm{out}}&lt;0.39)</span> (95%), whereas the M87* bound is limited by its mass systematics.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338392","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}