We present a systematic reassessment of cosmological constraints beyond ΛCDM by progressively relaxing the assumptions underlying Dark Energy (DE), Curvature, Neutrinos, and Inflation. Using the latest CMB data together with DESI BAO and different SN catalogues, we show that the preference for dynamical DE persists across all the extended cosmologies considered. Ωk remains compatible with flatness, despite a mild 2.2σ preference for Ωk > 0 that is substantially degraded in dynamical DE extensions. Constraints on Neff are broadly consistent with Neff=3.04, while cosmological upper limits on the total neutrino mass vary substantially across the cosmologies explored, ranging from ∑mν ≲ 0.06 eV to ≲ 0.2 eV. We quantify both the preference for the mass ordering and the apparent tension between cosmology and oscillation experiments, showing that they are strongly framework dependent. We find no evidence for inflationary tensor modes, with r ≲ 0.035. Constraints on the spectral index ns show significant model dependence. Allowing for the scalar runnings produces a mild shift toward αs > 0 and βs > 0 that can reabsorb the preference for larger ns found in small-scale CMB data, although both αs and βs remain consistent with zero at ∼ 1.5σ. We highlight the implications for slow-roll inflation and benchmark models. None of the extensions considered here can resolve the H0 tension. We discuss the implications for Ωm and S8. Overall, dynamical DE is the only significant deviation from ΛCDM and has the strongest impact on the inferred conclusions in the other sectors of the model.
This review explores the physical mechanisms driving the evolution of low- and intermediate-mass binary star systems, with particular emphasis on emerging mechanisms that challenge classical paradigms. We begin by describing the principal formation channels and orbital properties of binary systems. A critical reassessment of the Roche lobe formalism is presented, focusing on systems with eccentric orbits and asynchronous rotation, where deviations from traditional approximations become significant. We then review current theoretical models of mass and angular momentum exchange via Roche-lobe overflow, incorporating results from recent hydrodynamical simulations of wind accretion. The review also reports advances in tidal dissipation theory. Finally, we explore mechanisms capable of sustaining or exciting orbital eccentricity, including perturbations induced by mass transfer and interactions with circumbinary disks. These discussions aim to outline underexplored facets of binary evolution, offering new perspectives for theoretical and observational studies.
In this paper I review recent results on high-energy neutrino astronomy and what they can reveal about some of the most extreme cosmic accelerators. I discuss recent measurements of the diffuse TeV-PeV cosmic neutrino spectrum by the IceCube observatory and the current flux limits in the ultra-high-energy regime, contextualizing the recent detection of an ultra-high-energy neutrino by the KM3NeT observatory. I review the recent emergence of a TeV signal from nearby Seyfert galaxies such as NGC 1068, the potential of γ-ray blazars as neutrino sources above the PeV regime, and the current status of tidal disruption events and other transient classes as possible neutrino sources. For each of these topics, I discuss ongoing developments in source models and their current limitations. I argue for the indispensable role of next-generation multi-messenger facilities, such as IceCube-Gen2, in solidifying current source associations, probing the ultra-high-energy regime, and resolving vast transient populations that remain unidentified with current statistics.
Precise astrometric and photometric measurements of celestial point sources are fundamental to modern astronomy. These measurements, used to determine object positions, motions, and fluxes, are based on observational models that have evolved from empirical centroiding rules to rigorous probabilistic formulations at the pixel level. This review summarizes key contributions that formalized this transition and analyzes seminal works addressing both the theoretical limits and the empirical performance of estimators. Central to these developments is the derivation of fundamental bounds, such as the Cramér-Rao Lower Bound (CRLB), and the assessment of widely used estimators, including Maximum Likelihood (ML), Least Squares (LS), and Weighted Least Squares (WLS). These studies show that, while the CRLB sets a theoretical benchmark, practical estimators achieve it only under specific signal-to-noise ratio (SNR) regimes, with notable discrepancies in high-SNR conditions. Moreover, recent results demonstrate that jointly estimating source flux and background significantly improves photometric precision compared to sequential approaches. Looking ahead, the increasing complexity of astronomical surveys, driven by massive data volumes, dynamic observational conditions, and the integration of machine learning, poses new challenges to reliable inference. In this context, tools from statistical theory, including performance bounds and theoretically grounded estimators, remain critical to guide algorithm design and ensure robust astrometric and photometric pipelines.
The search for extrasolar photosynthetic life is one of the most important goals for modern astrobiology. Recent discoveries of cold brown dwarfs, as well as planets orbiting M-, G-, K-, and F-type main-sequence stars, have expanded opportunities to search for photosynthetic biosignatures within their habitable zones. This comprehensive review synthesizes current knowledge and emerging trends in the field. The paper addresses stellar variability and how spectral energy distribution influences potential pigment evolution and photoprotective adaptations, whether photosynthetic life could exist on peculiar exoworlds with specific illumination and surface conditions, as well as observational strategies with current and future telescopes. The goal of this work is to help researchers navigate the vast sea of knowledge by providing a strategic roadmap for prioritizing targets and interpreting potential biosignatures.
