物理最新文献

{"title":"Assessment of free volume using positron annihilation study in Ag2O-doped ZnO-P2O5-SeO2 glass ceramics","authors":"M. Kostrzewa,&nbsp;G. Naga Koti Reddy,&nbsp;A. Venkata Sekhar,&nbsp;A. Ingram,&nbsp;N. Purnachand,&nbsp;G. Sahaya Baskaran,&nbsp;G. Naga Raju,&nbsp;V. Ravi Kumar,&nbsp;Nalluri Veeraiah","doi":"10.1007/s00339-025-09028-2","DOIUrl":"10.1007/s00339-025-09028-2","url":null,"abstract":"<div><p>Glass ceramics with the composition ZnO–P₂O₅–SeO₂ doped with varying amounts of silver oxide (Ag₂O) were synthesized. The effect of Ag₂O on atomic vacancy formation was studied using positron annihilation lifetime spectroscopy (PALS). XRD and SEM studies confirmed the presence of Ag₃PO₄, Ag₂SeO₃ crystal phases, and Ag⁰ nanoparticles in the glassy matrix. Infrared spectroscopy showed that increasing Ag₂O content enhanced the fraction of Ag⁰ nanoparticles in the glass network while decreasing the fraction of ZnO₄ and [SeO₄]²⁻ units. This change indicated an increase in free volume defects, such as voids, that trap positrons. Analysis of positron annihilation lifetime spectra revealed an increase in the longest-lived component (I₃) and its lifetime (τ₃) with higher Ag₂O concentrations, indicating greater void expansion and agglomeration in the glass ceramic. These findings correspond to changes in ac conductivity and suggested that these glass ceramics could be developed as solid electrolytes for solid-state batteries.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 11","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145316364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural and magnetic tailoring of Co-Cu ferrite nanoparticles via Cd2+ substitution: a multi-characterization approach","authors":"D. El-Said Bakeer,&nbsp;M. Y. El Sayed,&nbsp;E. M. Abdallah,&nbsp;R. Awad,&nbsp;S. G. Elsharkawy","doi":"10.1007/s00339-025-08897-x","DOIUrl":"10.1007/s00339-025-08897-x","url":null,"abstract":"<div><p>This study investigates the structural and magnetic tunability of Co–Cu ferrite nanoparticles via dual-site substitution of Cd²⁺ at both Co²⁺ and Cu²⁺ lattice sites in the Co_0.5Cu_0.5Fe₂O₄ spinel lattice. Nanoparticles with the nominal composition Co_0.5−xCu_0.5−xCd_2xFe₂O₄ (x = 0.00, 0.01, 0.02, 0.04, 0.06) were synthesized using an efficient co-precipitation method. The large ionic radius of Cd²⁺ promotes its occupation of tetrahedral sites, which disrupts the magnetocrystalline anisotropy associated with Co²⁺ and the Jahn–Teller distortions associated with Cu²⁺, leading to cation redistribution, modifications in superexchange interactions, and potentially the initiation of spin canting. Compared to single-site doping, this dual-site substitution introduces greater structural and magnetic complexity, offering a promising approach for multifunctional ferrite design. X-ray diffraction (XRD) confirmed a predominant face-centered cubic spinel phase with Co_0.5Cu_0.5Fe₂O₄ as the primary phase and a minor hematite (Fe₂O₃) secondary phase. Increasing Cd²⁺ content induced a systematic lattice parameter expansion and crystallite size reduction (from 15.47 nm to 12.11 nm), indicating lattice distortion due to ionic substitution. TEM analysis showed quasi-spherical, slightly agglomerated nanoparticles with sizes decreasing from 15.47 nm to 12.11 nm as x increased from 0.00 to 0.06. HRTEM confirmed the material’s polycrystalline nature through observed (220) and (311) lattice fringes. FTIR spectra displayed two characteristic absorption bands 510–580 cm⁻¹ and 400–450 cm⁻¹) confirming spinel formation, while Raman spectroscopy revealed a blue shift in the <span>(:{A}_{1g})</span>mode, associated with Fe³⁺ migration towards tetrahedral sites. Additionally, XPS analysis confirmed the oxidation states of the constituent elements in the samples as Co²⁺, Cu²⁺, Fe³⁺, Cd²⁺and O²⁻. Vibrating sample magnetometry (VSM) measurements showed ferromagnetic hysteresis loops with a non-linear variation of saturation magnetization (<span>(:{M}_{s})</span>) and a significant reduction in coercivity (<span>(:{H}_{c})</span>) from 851.98 G to 306.06 G, reflecting progressive magnetic softening with Cd²⁺ incorporation. Complementary, ESR analysis showed asymmetric resonance line shapes, a downshift in <span>(:{H}_{r})</span>, and an enhancement in the Landé <span>(:g)</span> -factor, which was consistent with modifications in the local magnetic environment. These tunable structural and magnetic properties highlight the potential of Cd-substituted Co–Cu ferrites for applications in high-frequency electronics and EMI shielding.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 11","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00339-025-08897-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145316372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Biochemical Indicator of the Effectiveness of Isometric Exercises in Early Rehabilitation of Elderly Patients after Hip Arthroplasty","authors":"E. A. Maksimova,&nbsp;V. I. Shevchenko,&nbsp;K. S. Krasnov,&nbsp;A. S. Senotov,&nbsp;O. V. Lobanova,&nbsp;V. S. Akatov","doi":"10.1134/S0006350925700587","DOIUrl":"10.1134/S0006350925700587","url":null,"abstract":"<div><p>Improving the effectiveness of early rehabilitation of elderly patients after hip arthroplasty remains an urgent task. The aim of the study was to evaluate the effectiveness of isometric exercises in early (2 weeks) rehabilitation of elderly patients after hip replacement using blood parameters. The randomized study included ten elderly patients in the control (<i>n</i> = 5) and experimental (<i>n</i> = 5) groups with isometric exercises and rehabilitation techniques that were performed daily from 1 to 12 days after total cement hip arthroplasty. The effectiveness of rehabilitation was assessed by the indices of muscle traumatization (myoglobin, creatine phosphokinase, aspartate aminotransferase, and lactate dehydrogenase concentrations) and systemic inflammation (erythrocyte sedimentation rate, CRP concentrations, and interleukins IL-6, IL-8, and IL-1β) in the blood of patients on the 12th day after surgery. The indices of muscle traumatization and the concentrations of C-reactive protein and leukocytes in blood, as well as the erythrocyte sedimentation rate did not reveal any significant difference between the groups of patients. The difference between the control and experimental groups in terms of restoration of interleukin IL-6, IL-8, and IL-1β concentrations in the blood to the normal range was statistically significant according to Fisher’s exact test (<i>p</i> = 0.042). In general, these results showed that additional isometric exercises provided more effective early rehabilitation of elderly patients after endoprosthesis in comparison with the standard set of exercises and that normalization of the concentration of proinflammatory interleukins, primarily IL-6 and IL-8, can be considered as an objective indicator in assessing the effectiveness of methods of early rehabilitation of elderly patients after hip arthroplasty.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 3","pages":"553 - 560"},"PeriodicalIF":4.033,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of time temperature profiles for thermoluminescence glow curve analysis of MgSO4:Dy2O3 powder in TLD applications","authors":"Hayder Salah Naeem,&nbsp;Iskandar Shahrim Mustafa,&nbsp;N. N. Yusof,&nbsp;M. I. Sayyed,&nbsp;Ammar Nadal Shareef,&nbsp;Alghareeb Abbas Abdulhussein Mohammed,&nbsp;Ali Q. Tuama,&nbsp;Thair Hussein Khazaalah,&nbsp;Nabasu Seth Ezra,&nbsp;Oke Aduragbemi Olaoluwa,&nbsp;Munirah Jamil,&nbsp;G. I. Efenji,&nbsp;Muhammad Fadhirul Izwan bin Abdul Malik","doi":"10.1007/s00339-025-08994-x","DOIUrl":"10.1007/s00339-025-08994-x","url":null,"abstract":"<div><p>In the current study, the demand for highly sensitive radiation dosimeters is increasing, prompting the exploration of novel materials for thermoluminescence dosimetry (TLD). This research investigates the potential of MgSO₄:Dy₂O₃ powders as new TLDs, comparing their performance against the commercial dosimeter TLD-100. The samples were prepared: (MgSO₄)_1-x(Dy₂O₃)_x with x = 0.01, 0.05, 0.1, 0.5. These samples were synthesized using thermal treatment at temperatures of 600–1000 °C for 6, 8 h. The samples were characterized to assess crystallization using X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and energy dispersive X-ray (EDX) spectroscopy and mapping. Fourier transform infrared (FTIR) and raman spectroscopy were employed to verify the physicochemical composition and vibrational characteristics of the thermoluminescent (TL) materials. Optimization and dosimetric evaluations were conducted using X-ray irradiation at low doses, followed by readout with a Harshaw TLD-3500 reader. The XRD patterns confirmed the crystalline nature of the powders. Dosimetric capabilities were assessed by exposing the prepared samples to 2.97 mGy of X-ray radiation for ten cycles. The samples MSD0.5, optimized at 900 °C for 6 h in powder form, exhibited the highest sensitivity and dose response, with TLD readings of 458.95 nC, compared with 213.45 nC for TLD-100. The significant increase in sensitivity, along with stable time temperature profile (TTP) settings, suggests improved accuracy, positioning these materials as promising candidates for high performance radiation dosimetry in both environmental monitoring and medical applications.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 11","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145316371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quenching of the Spheroiden Triplet State with Oxygen in the Reaction Centers of C. sphaeroides in the Temperature Range 0–45°C","authors":"P. P. Knox,&nbsp;I. A. Yaroshevich,&nbsp;E. P. Lukashev","doi":"10.1134/S0006350925700496","DOIUrl":"10.1134/S0006350925700496","url":null,"abstract":"<div><p>The lifetime of the triplet state of the carotenoid, spheroiden (^TCar) in the photosynthetic reaction center of the purple bacteria <i>Cereibacter</i> (<i>Rhodobacter</i>) <i>sphaeroides</i> in the temperature range from 0 to 45°C and the effect of the concentration of molecular oxygen in the medium on this time was studied. <i>O</i>-phenanthroline (10^–2 M), which partially displaces the primary quinone acceptor from the structure of the reaction center, was added to the preparations to form ^TCar upon light excitation of the reaction center. The activation energies of the ^TCar quenching process were determined under normal aerobic conditions and during partial degassing of the studied preparations.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 3","pages":"434 - 441"},"PeriodicalIF":4.033,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro Interaction of Titin and Myosin-Binding Protein С","authors":"T. A. Uryupina,&nbsp;M. A. Timchenko,&nbsp;L. G. Bobyleva,&nbsp;N. V. Penkov,&nbsp;A. G. Gabdulkhakov,&nbsp;P. V. Nekrasov,&nbsp;S. N. Udaltsov,&nbsp;I. M. Vikhlyantsev,&nbsp;A. G. Bobylev","doi":"10.1134/S0006350925700447","DOIUrl":"10.1134/S0006350925700447","url":null,"abstract":"<div><p>The study of the basic biophysical principles underlying protein aggregation is a relevant area of modern biophysics, which is of great importance for elucidating the disruption of the protein aggregation process in pathologies and age-related changes. In this work, the morphological and structural features of coaggregates of two muscle proteins of the sarcomeric cytoskeleton (titin and myosin-binding protein C) were studied using atomic force microscopy, FTIR spectroscopy, and fluorimetry using the dye thioflavin T and X-ray diffraction. It was found that depending on the ionic strength of the solution coaggregation of these proteins occurs with the formation of structures with different morphologies. In particular, in a solution containing 30 mM KCl, structures resembling a film with multiple ruptures were observed, while in a solution containing 150 mM KCl the studied proteins formed spherical aggregates. When the aggregates of the studied proteins interacted with thioflavin T, the fluorescence intensity of titin and C-protein complexes that formed at lower ionic strength (30 mM KCl) increased, which may indicate the amyloid nature of the studied aggregates. The FT-IR spectrum of titin and C-protein complexes had two broad peaks; the presence of one of these (between 1611 and 1630 cm^–1) is characteristic of amyloid aggregates. However, the reflections related to the cross-β-structure that are characteristic of amyloid protein aggregates were not detected in these complexes by X-ray diffraction. Similar results were obtained by X-ray diffraction method in the study of coaggregates of the studied proteins formed in a solution with higher ionic strength. Thus, depending on the ionic strength of the solution, coaggregates of titin and myosin-binding protein C are formed that are different in morphology and in their ability to bind thioflavin T. The in vitro data expand the understanding of the peculiarities of aggregation of sarcomeric muscle proteins and are important for a better understanding of their interaction in sarcomeres in vivo. The results of the study are relevant in the context of age-related changes in muscle tissue and may be important for the development of approaches aimed at maintaining normal muscle contractile function in the elderly. The interaction of the investigated proteins in the sarcomere can be considered as a potential molecular target for interventions related to physical activity management in aging.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 3","pages":"379 - 386"},"PeriodicalIF":4.033,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis with biosynthesized nanoparticles by reducing and capping of identified Pterocarpus Santalinus bioactive compounds","authors":"Swarna Kumari Kanthireegala,&nbsp;Lokesh Reddy Bandi,&nbsp;Sindu Kadapana,&nbsp;Dakshayani Lomada,&nbsp;Veeranjaneya Reddy Lebaka,&nbsp;Madhava C. Reddy,&nbsp;Suresh V. Chinni,&nbsp;Subash C.B. Gopinath","doi":"10.1007/s00339-025-08989-8","DOIUrl":"10.1007/s00339-025-08989-8","url":null,"abstract":"<div>\u0000 \u0000 <p>This research analyzed <i>Pterocarpus santalinus</i> leaf extract using LC-MS and identified 39 bioactive components, including isorhamnetin, kaempferol, quercetin, and trifolin. Silver and copper nanoparticles (PsAgNPs and PsCuONPs) were synthesized using reducing and capping of identified bioactive compounds and characterized using UV-Vis spectroscopy, XRD, FTIR, FESEM, TEM, Zeta potential, and DLS. PsAgNPs exhibited higher antibacterial activity against drug-resistant strains, with inhibition zones of 18 mm for <i>Escherichia coli</i> and 17 mm for <i>Staphylococcus aureus</i> at 100 µg/mL. In comparison, PsCuONPs showed inhibition zones of 16 and 14 mm at 175 µg/mL, respectively. PsAgNPs demonstrated antibacterial action at lower concentrations (MIC and MBC values at 50–75 µg/mL) compared to PsCuONPs (100 µg/mL). Both nanoparticles induced bacterial membrane perforation and cellular lysis, confirmed by FESEM. Additionally, PsAgNPs demonstrated superior anti-biofilm, antioxidant (DPPH: 6.97 µg/mL; ABTS: 3.92 µg/mL), and anti-inflammatory activities, inhibiting hemolysis (IC₅₀ = 4.17 µg/mL) and protein denaturation (IC₅₀ = 6.33 µg/mL) compared to PsCuONPs. Moreover, they displayed higher cytotoxicity against human breast cancer cell lines. This data suggests that PsAgNPs and PsCuONPs could be promising therapeutic molecules for antibacterial, anti-oxidative, anti-inflammatory, and anti-cancer applications.</p>\u0000 </div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 11","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145316301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Mild Toxic Effect of Dinitrosyl Iron Complexes during Inhalation of Syrian Hamsters in a “Nose-Only” Chamber","authors":"S. V. Ankov,&nbsp;A. V. Shipovalov,&nbsp;K. S. Bogatischeva,&nbsp;N. A. Zhukova,&nbsp;A. F. Vanin,&nbsp;N. A. Tkachev,&nbsp;O. V. Pyankov,&nbsp;N. B. Asanbaeva,&nbsp;E. G. Bagryanskaya","doi":"10.1134/S0006350925700538","DOIUrl":"10.1134/S0006350925700538","url":null,"abstract":"<div><p>Using methods of general and biochemical blood analysis and histological analysis of the lungs, liver, heart and kidneys of Syrian hamsters, it was determined whether aerosol treatment of these animals with binuclear dinitrosyl iron complexes with glutathione, alone or followed by similar treatment of the same animals with diethyldithiocarbamate, as well as aerosol treatment of Syrian hamsters with dinitrosyl iron complexes with mercaptosuccinate, leads to negative toxic effects at the level of the whole organism. The detected weak reversible toxic effect in the form of nephrotoxicity of such treatment allows us to assert that such an effect, which suppresses of covid infection in these animals, is due to the selective in vivo action of dinitrosyl iron complexes and diethyldithiocarbamate on the SARS-CoV-2 virus, without affecting other tissues and organs of the animal.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 3","pages":"474 - 484"},"PeriodicalIF":4.033,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Granulocyte Colony-Stimulating Factor in the Form of Pegfilgrastim in Fractionated Irradiation of Mice","authors":"L. A. Romodin,&nbsp;A. A. Moskovskij,&nbsp;G. O. Abelev,&nbsp;O. V. Nikitenko,&nbsp;T. M. Bychkova,&nbsp;C. C. Sodboev,&nbsp;O. S. Aldoshina","doi":"10.1134/S000635092570054X","DOIUrl":"10.1134/S000635092570054X","url":null,"abstract":"<div><p>The radioprotective efficacy of granulocyte colony-stimulating factor in the form of pegfilgrastim at fractionated irradiation was evaluated on male ICR (CD-1) mice. Mice were exposed to five daily exposures to X-rays at a dose of 2.5 Gy. Three hours after each exposure, pegfilgrastim was injected subcutaneously into mice at a dosage of 0.5 μg/g. The drug was also administered daily 3–7 days after the last irradiation. The efficacy of this therapeutic regimen was evaluated on the basis of the degree of DNA damage in spleen cells 30 min after the last irradiation; hematologic parameters were evaluated after 30 min and 3 days; Schiff bases, trieno, and oxodiene conjugates in the liver were evaluated after 30 min; and thymus and spleen weight, the number of karyocytes in the femur, and the content of thiobarbiturate-reactive products in the liver were evaluated after 3 days, as well as on the basis of 30-day survival. The application of the therapeutic regimen contributed to a significant correction of irradiation-induced oxidative stress: according to the criteria of the content of Schiff bases, trieno and oxodieno conjugates, the group receiving pegfilgrastim corresponded to the intact mice, the content of thiobarbiturate-reactive products in the liver decreased relative to the irradiated control, but the parameters of intact mice were not reached. Pegfilgrastim administration did not compensate for the irradiation-induced bone marrow cell death 3 days after the last irradiation and could eventually ensure the survival of only 3 mice out of 14 individuals receiving the drug. Thus, for effective application of pegfilgrastim during fractionated irradiation at a total dose of 12.5 Gy it is necessary to increase the number of irradiation sessions with decreasing dose of each session, or to decrease the total radiation dose. Joint use of pegfilgrastim with other radioprotective drugs with other mechanisms of action is also promising.</p></div>","PeriodicalId":493,"journal":{"name":"Biophysics","volume":"70 3","pages":"485 - 497"},"PeriodicalIF":4.033,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145327554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Running gravitational constant induced dark energy as a solution to (sigma _8) tension","authors":"Tilek Zhumabek,&nbsp;Azamat Mukhamediya,&nbsp;Hrishikesh Chakrabarty,&nbsp;Daniele Malafarina","doi":"10.1140/epjc/s10052-025-14917-0","DOIUrl":"10.1140/epjc/s10052-025-14917-0","url":null,"abstract":"<div><p>We consider a modified gravity model with a running gravitational constant coupled to a varying dark energy fluid and test its imprint on the growth of structure in the universe. Using redshift space distortion (RSD) measurement results, we show a tension at the <span>(3 sigma )</span> level between the best fit <span>(Lambda )</span>CDM and the corresponding parameters obtained from the Planck data. Unlike many modified gravity-based solutions that overlook scale dependence and model-specific background evolution, we study this problem in the broadest possible context by incorporating both factors into our investigation. We performed a full perturbation analysis to demonstrate a scale dependence in the growth equation. Fixing the scale to <span>(k = 0.1 h)</span> Mpc<span>(^{-1})</span> and introducing a phenomenological functional form for the varying Newton coupling <i>G</i> with only one free parameter, we conduct a likelihood analysis of the RSD selected data. The analysis reveals that the model can bring the tension level within <span>(1 sigma )</span> while maintaining the deviation of <i>G</i> from Newton’s gravitational constant at the fifth order.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 10","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14917-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145316369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}