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We run a three-dimensional Galactic chemical evolution (GCE) model to follow the propagation of ⁵³Mn (exclusively produced from type Ia supernovae, SNIa), ⁶⁰Fe (exclusively produced from core-collapse supernovae, CCSNe), ¹⁸²Hf (exclusively produced from intermediate mass stars, IMSs), and ²⁴⁴Pu (exclusively produced from neutron star mergers, NSMs). By comparing the predictions from our three-dimensional GCE model to recent detections of ⁵³Mn, ⁶⁰Fe, and ²⁴⁴Pu on the deep-sea floor, we draw conclusions about their propagation in the interstellar medium.

We revisit the problem of the positive correlation between age and Galactocentric distance seen in Galactic Classical Cepheids, which at first sight may seem counter-intuitive in the context of inside-out galaxy formation. To explain it, we use the Besançon Galaxy Model and a simulation of star particles in the Galactic disc coupled with stellar evolutionary models. We then select Classical Cepheids from this simulation and test in qualitative terms which ingredients are necessary to find agreement with the observational data. We show that the interplay of the Galactic disc's metallicity gradient and the metallicity dependence of the Cepheids' life-time in the instability strip results in a pronounced positive age-Galactocentric distance relation. This renders a reconstruction of the recent star-formation history based on Classical Cepheids unrealistic. It also has important consequences on our interpretation of the observed scatter about the radial metallicity gradient measured with Galactic Classical Cepheids.

In this work, we start from the hypothesis that the universe lives in a Gravitational Wave Background (GWB). From this hypothesis, it follows that space–time is not locally flat because we have to take into account the fluctuations of the GWB in space–time. This implies that sufficiently small particles will feel these oscillations, preventing them from following geodesic trajectories. Thus, in a previous work, it was shown that if these particles follow the geodesic trajectories plus a stochastic term due to space–time fluctuations, the field equation for these quantum particles is simply the Klein–Gordon equation in this arbitrary curved space–time. In this work, we analyze these geodesics plus the stochastic trajectories in a Schwarzschild black hole.

In this paper, we present the latest results of our ongoing multiplicity survey of (Community) TESS Objects of Interest, using astrometry and photometry from the latest data release of the ESA Gaia mission to detect stellar companions of these stars and to characterize their properties. A total of 92 binary and two hierarchical triple star systems are identified among the 745 target stars whose multiplicity is explored in this study, all at distances of less than 500 pc around the Sun. As expected for components of gravitationally bound star systems, the targets and the detected companions are at the same distance and share a common proper motion, as shown by their accurate Gaia astrometry. The companions have masses of about 0.12 to 1.6 $��M_{\odot }�$ and are most frequently found in the mass range up to 0.6 $��M_{\odot }�$. The companions have projected separations from the targets between about 110 and 9600 au. Their frequency is highest and constant from about 300 to 800 au, decreasing at larger projected separations. In addition to main sequence stars, five white dwarf companions are detected in this study, whose true nature is unveiled by their photometric properties.

We investigate the effects of a minimal measurable length on neutron stars, within the quantum hadrodynamics (QHD-I) model modified by the Generalized Uncertainty Principle (GUP). Working in a deformed Poisson algebra framework, we incorporate GUP effects via a time-invariant transformation of the phase space volume, effectively reducing the number of accessible quantum states at high momentum. We focus specifically on two observables critical to this star physics, the compressibility, which encapsulates how stiff EOS become, and the speed of sound, which imposes a causality constraint. Using this model as an exploratory study, due to its simplicity and structured description, we perform a preliminary analysis of GUP effects with a minimum spacetime length on these compact objects. This deformation increases the speed of sound while decreasing the compressibility, and we identify critical values of the Fermi momentum beyond which both quantities become nonphysical. These results underscore the potential role of a minimal length scale in shaping the bulk properties and possible phase structures of dense matter in neutron stars.

Recent observational results, such as those from pulsar timing arrays (PTA), suggest a low-frequency Gravitational Wave Background (GWB) permeates our universe. This opens the possibility that gravitational waves could span a broader spectrum, potentially impacting cosmological scales. Among novel Dark Energy (DE) models that explain DE as a very low-frequency GWB, the Compton Mass Dark Energy model (CMaDE) has shown promising theoretical alignment with cosmic acceleration. In this study, we explore the cosmological implications of the CMaDE model when coupled with Scalar Field Dark Matter (SFDM) as the dark matter candidate. We numerically solve the cosmological evolution equations for this combined CMaDE+SFDM framework, examining its impact on key observables and comparing results to the standard $��\mathrm{\Lambda CDM}�$ model. Our findings demonstrate that the CMaDE+SFDM model is broadly consistent with $��\mathrm{\Lambda CDM}�$, showing similar evolution in observables such as the cosmic microwave background and the background energy densities, with some deviations that merit further investigation.