Physics of the Dark Universe最新文献

{"title":"Effect of primary scalar hair on black hole’s strong lensing in Beyond Horndeski gravity","authors":"Mohsen Fathi","doi":"10.1016/j.dark.2025.102069","DOIUrl":"10.1016/j.dark.2025.102069","url":null,"abstract":"<div><div>We study the gravitational lensing effects of a static, asymptotically flat black hole with primary scalar hair in Beyond Horndeski gravity, focusing on the strong lensing regime. Recently, in Ref. Erices and Fathi (2025), we placed constraints on the scalar hair parameter by analyzing its thermodynamic stability and the black hole shadow. In this work, we further investigate the strong lensing properties of the black hole, which form the basis of shadow formation, and employ observational data from the Event Horizon Telescope to derive more precise constraints on the scalar hair parameter. Additionally, we compute the shape and position of different lensed images of a thin accretion disk and argue that the observed black hole shadow corresponds to the secondary image of the emitting disk. Using this interpretation, we perform a new set of constraints on the scalar hair. Furthermore, we discuss why higher-order images are not suitable for astrophysical constraints, highlighting the limitations posed by their faintness and observational challenges. Finally, we find that models satisfying these constraints exhibit local instabilities.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102069"},"PeriodicalIF":6.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144989289","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":"Compartmentalization in the dark sector of the universe after DESI DR2 BAO data","authors":"Marcel van der Westhuizen ,&nbsp;David Figueruelo ,&nbsp;Rethabile Thubisi ,&nbsp;Shambel Sahlu ,&nbsp;Amare Abebe ,&nbsp;Andronikos Paliathanasis","doi":"10.1016/j.dark.2025.102107","DOIUrl":"10.1016/j.dark.2025.102107","url":null,"abstract":"<div><div>We study a non-linear interaction between the dark matter and dark energy components of the universe. Within a spatially flat FLRW geometry, dark matter is described by a dust fluid and dark energy by an ideal gas with a constant equation-of-state parameter, allowing for energy transfer between the two sectors. The resulting effective fluid leads to a unified dynamical dark energy model in which the Hubble function admits an analytic expression. We constrain this model using the DESI DR2 Baryon Acoustic Oscillation (BAO) measurements and the Pantheon+ Type Ia supernovae (SNe Ia) compilation. For the combined dataset, the interacting model provides a better fit than <span><math><mi>Λ</mi></math></span>CDM, with <span><math><mrow><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>Interaction</mi></mrow><mrow><mn>2</mn></mrow></msubsup><mo>−</mo><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>Λ</mi><mi>CDM</mi></mrow><mrow><mn>2</mn></mrow></msubsup><mo>=</mo><mo>−</mo><mn>5</mn></mrow></math></span>. Using the Akaike Information Criterion (AIC), we find <span><math><mrow><msub><mrow><mtext>AIC</mtext></mrow><mrow><mi>Interaction</mi></mrow></msub><mo>−</mo><msub><mrow><mtext>AIC</mtext></mrow><mrow><mi>Λ</mi><mi>CDM</mi></mrow></msub><mo>=</mo><mo>−</mo><mn>1</mn></mrow></math></span>, indicating that the interacting model is weakly preferred, though the difference is not statistically significant and disappears when considering BAO data alone. Finally, when comparing the interaction with the <span><math><mrow><msub><mrow><mi>w</mi></mrow><mrow><mn>0</mn></mrow></msub><msub><mrow><mi>w</mi></mrow><mrow><mi>a</mi></mrow></msub></mrow></math></span>CDM (CPL) model, we find a small preference for the interaction in the BAO-only case, with <span><math><mrow><msub><mrow><mtext>AIC</mtext></mrow><mrow><mi>Interaction</mi></mrow></msub><mo>−</mo><msub><mrow><mtext>AIC</mtext></mrow><mrow><msub><mrow><mi>w</mi></mrow><mrow><mn>0</mn></mrow></msub><msub><mrow><mi>w</mi></mrow><mrow><mi>a</mi></mrow></msub></mrow></msub><mo>=</mo><mo>−</mo><mn>1</mn><mo>.</mo><mn>5</mn></mrow></math></span>.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102107"},"PeriodicalIF":6.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266913","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":"Optical properties of black holes immersed in Galactic Dark Matter Halo","authors":"Aqsa Mehmood ,&nbsp;A. Eid ,&nbsp;M. Umair Shahzad ,&nbsp;Abdul Malik Sultan","doi":"10.1016/j.dark.2025.102115","DOIUrl":"10.1016/j.dark.2025.102115","url":null,"abstract":"<div><div>We present a comprehensive investigation into the optical and topological properties of black holes (BHs) immersed in a Galactic Dark Matter Halo (GDMH). Our analysis focuses on shadow morphology, photon ring luminosity, and thermodynamic classification, using spherically symmetric accretion models in both static and infalling frameworks. In both scenarios, we observe that the shadow radius decreases monotonically with increasing halo parameter (<span><math><mi>a</mi></math></span>), reflecting the influence of dark matter on photon trajectories. Within the static accretion model, the brightness of the photon ring intensifies significantly with increasing <span><math><mi>a</mi></math></span>, more prominently than with variations in the asymptotic circular velocity (<span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>). BHs surrounded by radially infalling accretion flows exhibit darker shadows compared to those with static flows, a consequence of relativistic Doppler dimming; however, the shadow size remains invariant, reaffirming its geometric origin. We further analyze the visual manifestation and observational significance of these luminous features, including shadow contours and intensity profiles. Finally, using the generalized off-shell Helmholtz free energy framework, we classify the BH in GDMH as belonging to the <span><math><msup><mrow><mi>W</mi></mrow><mrow><mn>1</mn><mo>−</mo></mrow></msup></math></span> topological class, indicating a thermodynamically unstable configuration with a single negative winding number.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102115"},"PeriodicalIF":6.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266915","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":"Decoding dark matter admixed neutron stars: From static structure to rotational deformation","authors":"Pinku Routaray ,&nbsp;Abirbhav Chakrawarty ,&nbsp;N.K. Patra ,&nbsp;Bharat Kumar","doi":"10.1016/j.dark.2025.102093","DOIUrl":"10.1016/j.dark.2025.102093","url":null,"abstract":"<div><div>In this study, we investigate the impacts of dark matter (DM) on the properties of both static and rotating neutron stars utilizing a self-interacting DM model, motivated by the neutron decay anomaly. DM-admixed NSs are modeled by assuming chemical equilibrium between ordinary matter and the dark sector, treating a single-fluid Tolman–Oppenheimer–Volkoff (TOV) framework. By treating the DM interaction strength (<span><math><mi>G</mi></math></span>) as a free parameter, we explore its influence on NS properties, considering a broad range of equations of state (EoSs). Using the mass–radius constraints from NICER pulsar measurements, we constrain the DM interaction strength for each EoS via a likelihood analysis. Extending this model to rotating NSs, we analyze how centrifugal forces associated with increasing angular velocity (<span><math><mi>Ω</mi></math></span>) enhance both mass and radius, causing deformation. We assess the impact of DM on rotational deformation by calculating the eccentricity, highlighting the interplay between DM and rotational forces. Since both DM and rotation simultaneously influence NS properties, we compute the relative changes in mass and radius across varying <span><math><mi>G</mi></math></span> and <span><math><mi>Ω</mi></math></span> values to quantify their combined effects.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102093"},"PeriodicalIF":6.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109400","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":"I. Linear interacting dark energy: Analytical solutions and theoretical pathologies","authors":"Marcel van der Westhuizen ,&nbsp;Amare Abebe ,&nbsp;Eleonora Di Valentino","doi":"10.1016/j.dark.2025.102119","DOIUrl":"10.1016/j.dark.2025.102119","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Interacting dark energy (IDE) models, in which dark matter (DM) and dark energy (DE) exchange energy through a non-gravitational interaction, have long been proposed as candidates to address key challenges in modern cosmology. These include the coincidence problem, the &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; tensions, and, more recently, the hints of dynamical dark energy reported by the DESI collaboration. Given the renewed interest in IDE models, it is crucial to fully understand their parameter space when constraining them observationally, especially with regard to the often-neglected issues of negative energy densities and future big rip singularities. In this work, we present a comparative study of the general linear interaction &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;Q&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;dm&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;dm&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;de&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;de&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and four special cases: &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;Q&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;dm&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;de&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;Q&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;dm&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;de&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;Q&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;dm&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;Q&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;mi&gt;δ&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;de&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. For these five models, we perform a dynamical system analysis and derive new conditions that ensure positive, real, and well-defined energy densities throughout cosmic evolution, as well as criteria to avoid future big rip singularities. We obtain exact analytical solutions for &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;dm&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;de&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, the effective equations of state (&lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;eff&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;dm&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;eff&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;de&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;msubsup&gt;&lt;mrow&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;eff&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;tot&lt;/mi&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/math&gt;&lt;/span&gt;), and a reconstructed dynamical DE equation of state &lt;span&gt;&lt;mat","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102119"},"PeriodicalIF":6.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145320466","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":"Scalar perturbations of spacetime, greybody factors, weak deflection angles and shadows of black holes in Weyl geometric gravity theory","authors":"Shahid Chaudhary ,&nbsp;Muhammad Danish Sultan ,&nbsp;Asifa Ashraf ,&nbsp;Ali M. Mubaraki ,&nbsp;Saad Althobaiti ,&nbsp;Farruh Atamurotov ,&nbsp;Awatef Abidi","doi":"10.1016/j.dark.2025.102083","DOIUrl":"10.1016/j.dark.2025.102083","url":null,"abstract":"<div><div>We present a comprehensive theoretical investigation of black holes within the framework of Weyl geometric gravity which is a conformally invariant extension of General Relativity that naturally incorporates scalar and vector fields. Motivated by the growing need to explore gravitational dynamics beyond Einsteins theory particularly in regimes involving dark energy, dark matter, and quantum gravity we analyze a recently proposed Weyl black hole solution and uncover rich physical phenomena that depart significantly from classical expectations. Our study spans scalar perturbation dynamics, Hawking radiation via greybody factors, gravitational lensing in both vacuum and plasma environments, and shadow formation under infalling spherical accretion. We find that the Weyl coupling parameter <span><math><mi>δ</mi></math></span> and the cosmological curvature term <span><math><mrow><mn>1</mn><mo>/</mo><msup><mrow><mi>l</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span> act as powerful deformation parameters which significantly enhancing the black holes stability, effecting Hawking radiation, and enlarging and distorting shadow images. Using the Gauss–Bonnet theorem and Jacobi metric formalism, we derive novel analytical expressions for the deflection angles of photons and massive particles demonstrating pronounced velocity dependence and curvature-induced amplification of gravitational lensing. Furthermore, our optical modeling reveals that Weyl geometric effects leave distinct imprints on observed intensities and photon rings.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102083"},"PeriodicalIF":6.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105929","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":"Minimally complex fuzzy wormhole models in Einstein-Cartan theory of gravity","authors":"Z. Yousaf ,&nbsp;M. Rizwan ,&nbsp;Mohammad Alshammari ,&nbsp;Othman Abdullah Almatroud ,&nbsp;Saleh Alshammari ,&nbsp;M. Mossa Al-sawalha","doi":"10.1016/j.dark.2025.102082","DOIUrl":"10.1016/j.dark.2025.102082","url":null,"abstract":"<div><div>In this work, we explore the possibility of constructing minimally complex wormhole geometries supported by fuzzy dark matter, framed within the Einstein-Cartan gravity model. By using the realistic Einasto density profile to model dark matter haloes, we reveal how dark matter distributions can form and affect wormhole structures. The matter content is an anisotropic fluid with Weyssenhoff spin contributions, effectively including quantum spin effects in the relativistic anisotropic energy–momentum tensor. The wormhole shape function is determined by solving the field equations and the Einasto profile. We then probe further into the dark matter’s role in dictating important physical properties of the wormhole, such as the complexity factor, equation of state, equilibrium status, energy limits, and active gravitational mass. To further complement our results, a detailed graphical analysis is included, illustrating how dark matter can dictate the geometry and physical feasibility of such extreme spacetime geometries.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102082"},"PeriodicalIF":6.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057335","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":"Geometric properties, scalar perturbations and thermodynamics of a charged Lorentz-violating hairy black hole with quintessence-like field","authors":"Allan R.P Moreira ,&nbsp;Faizuddin Ahmed ,&nbsp;Abdelmalek Bouzenada","doi":"10.1016/j.dark.2025.102153","DOIUrl":"10.1016/j.dark.2025.102153","url":null,"abstract":"<div><div>In this work, we investigate a novel class of static, spherically symmetric black hole (BH) solutions that incorporate several fundamental physical features: electric charge, Lorentz symmetry violation, a surrounding cloud of strings, and an external quintessence-like field. The proposed metric generalizes earlier configurations by including a Lorentz-violating deformation inspired by the Kalb-Ramond field vacuum expectation value. We analyze the dynamics of null geodesics and characterize the effective potential, photon trajectories, and the conditions for circular orbits, photon sphere, and shadow formation. We further study the scalar perturbations by solving the Klein–Gordon equation in the BH background, revealing how various geometric and physical parameters influence the scalar potential. Additionally, we examine the thermodynamic behavior of the solution, computing key quantities such as the mass, Hawking temperature, heat capacity, and Gibbs free energy.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102153"},"PeriodicalIF":6.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145465214","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":"The impact on non-Gaussianities of the ISW-Lensing correlation in non-standard cosmologies","authors":"Matteo Forconi ,&nbsp;Alessandro Melchiorri","doi":"10.1016/j.dark.2025.102126","DOIUrl":"10.1016/j.dark.2025.102126","url":null,"abstract":"<div><div>The detection of non-Gaussianities (NG) in the Cosmic Microwave Background (CMB) is essential to better understand the early epochs of our Universe. One way to observe NG is to constrain the bispectrum, which usually is the largest non-trivial correlation function for most of the inflationary models. However, natural NG arise from late-time evolution and they need to be subtracted from the signal. In this work, we investigate the impact of different dark energy models to the bias induced by the cross-correlation between the Integrated Sachs–Wolfe effect and the weak lensing. More specifically, we compute the predictions for models of dynamical dark energy, <span><math><mrow><mi>w</mi><mo>≠</mo><mo>−</mo><mn>1</mn></mrow></math></span> and CPL parametrization, as well as different realizations of the sign-switching cosmological constant model.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102126"},"PeriodicalIF":6.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266299","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":"Search for deexcitations of 178m2Hf isomer induced by inelastic Dark Matter candidates in ultra-low-background conditions","authors":"P. Belli ,&nbsp;R. Bernabei ,&nbsp;F. Cappella ,&nbsp;V. Caracciolo ,&nbsp;R. Cerulli ,&nbsp;F.A. Danevich ,&nbsp;S.S. Drapey ,&nbsp;A. Incicchitti ,&nbsp;S.I. Kirischuk ,&nbsp;V.I. Kirischuk ,&nbsp;M. Laubenstein ,&nbsp;A. Leoncini ,&nbsp;V.I. Tretyak","doi":"10.1016/j.dark.2025.102113","DOIUrl":"10.1016/j.dark.2025.102113","url":null,"abstract":"<div><div>The <span><math><mi>γ</mi></math></span>-ray radiation from a ^178m2Hf source with an activity of <span><math><mrow><mo>≈</mo><mn>63</mn></mrow></math></span> Bq was measured for the first time with two ultra-low-background HPGe <span><math><mi>γ</mi></math></span> spectrometers over cumulative 1170 h deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN. The aim of the measurements was the search for deexcitations of the ^178m2Hf isomer induced by inelastic Dark Matter candidates. The process would lead to <span><math><mi>γ</mi></math></span>-ray emission from the excited levels of the ¹⁷⁸Hf that are not populated in the spontaneous decay of the ^178m2Hf. In this way improved limits on the half-life of eighteen inelastic-dark-matter-induced transitions, at the level of <span><math><mrow><mo>lim</mo><msub><mrow><mi>T</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>∼</mo><mn>4</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>5</mn></mrow></msup><mtext>–</mtext><mn>6</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>6</mn></mrow></msup></mrow></math></span> yr are derived. The parameters’ space of such inelastic candidates is also derived for some given model assumptions. Elements towards progress in sensitivity are briefly mentioned.</div></div>","PeriodicalId":48774,"journal":{"name":"Physics of the Dark Universe","volume":"50 ","pages":"Article 102113"},"PeriodicalIF":6.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266916","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}