Recent observations reveal the surprising breakdown of stellar gyrochronology relations at about the Sun's age hinting that middle-aged, solar-like stars transition to a magnetically inactive future. We provide a theoretical basis for these intriguing observations inspired by simulations with a mathematical dynamo model that can explore long-term solar cycle fluctuations. We reproduce the observed bimodal distribution of sunspot numbers, but only for subcritical dynamos. Based on a bifurcation analysis, we argue that ageing of solar-like stars makes the magnetically-weak dynamo regime readily accessible. Weak magnetic field production in this regime compromises wind-driven angular momentum losses thus disrupting the hegemony of magnetic braking on stellar rotational spin-down. This hypothesis of {\emph{subcritical magnetic dynamos}} of solar-like stars provides a self-consistent, unifying physical basis for a diversity of solar-stellar phenomena such as why stars beyond their mid-life do not spin-down as fast as in their youth, the break-down of stellar gyrochronology relations, the observed bimodal distribution of long-term sunspot observations and recent findings suggesting that
Radio pulsar observations probe the lives of Galactic double neutron-star (DNS) systems while gravitational waves enable us to study extragalactic DNS in their final moments. By combining measurements from radio and gravitational-wave astronomy, we seek to gain a more complete understanding of DNS from formation to merger. We analyse the recent gravitational-wave binary neutron star mergers GW170817 and GW190425 in the context of other DNS known from radio astronomy. By employing a model for the birth and evolution of DNS, we measure the mass distribution of DNS at birth, at mid-life (in the radio), and at death (in gravitational waves). We consider the hypothesis that the high-mass gravitational-wave event GW190425 is part of a subpopulation formed through unstable case BB mass transfer, which quickly merge in $\sim 10-100~\mathrm{Myr}$. We find mild evidence to support this hypothesis and that GW190425 is not a clear outlier from the radio population as previously claimed. If there are fast-merging binaries, we estimate that they constitute $8-79\%$ of DNS at birth (90% credibility). We estimate the typical delay time between the birth and death of fast-merging binaries to be $\a
We present a physics-based framework that runs from fundamental interactions and constants to biospheres, using a sequence of quantitative nonequilibrium thresholds ("gates"). Each gate is an inequality in measurable variables-free-energy flux, reaction-transport rates, replication fidelity, coding capacity, ecological closure, and climate feedback gains. Crucially, the gate vector is anchored in fundamental physics: dimensionless constants, nuclear resonance placements (e.g., the $^{12}$C Hoyle state), statistical mechanics (Landauer's bound $k_BT \ln 2$) fix the energetic, kinetic, information-theoretic margins that propagate through the gates. This anchoring lets us propagate sensitivities of the constants into biosphere-level metrics (net primary productivity (NPP), cycle-closure ratios, and climate feedback gain), yielding an end-to-end map from constants to biospheres. The framework is predictive: it yields testable inequalities, margin rankings, and population-level correlations between stellar and planetary boundary conditions and biosphere feasibility. It does not claim point predictions of life prevalence; rather, it specifies which gate margins are observable-bounded ver
We develop a Starshaped Mean Residual Life (SMEL) framework for survival data with non-monotonic hazard patterns, where early-stage attrition is followed by mid-career stabilization. Unlike Cox proportional hazards models or standard mean residual life models requiring monotonicity, SMEL accommodates complex temporal dynamics by requiring only that $m(t)/t$ be nondecreasing, formalizing the transition from vulnerability to equilibrium. We extend SMEL to regression settings via proportional mean residual life (PMRL) models, $m(t\mid Z)=m_0(t)\exp(Z^\topγ)$, with adaptive Bayesian estimation using three-parameter Weibull--resilience distributions and the No-U-Turn Sampler. Monte Carlo simulations across 48,000 datasets show SMEL-PMRL maintains bias $\leq 0.02$ under 40\% right-censoring, reduces integrated Brier score by 19\% over Cox models ($2.34$ vs.\ $2.88\times10^{-2}$), and achieves 5.4\% AIC improvement. Joint longitudinal-survival extensions via shared frailty enable simultaneous modeling of correlated time-to-event and continuous outcomes. Application to 169 rural STEM teachers (2018--2023, NSF Noyce) confirms starshaped equilibrium ($Λ=12.47$, $p=0.002$), with 38\% early-ca
Nulling interferometry is one of the most promising techniques that is envisioned for the imaging and characterization of exoplanets in the mid-infrared for ground-based and space-based observatories. On the ground, the upcoming Asgard/NOTT visitor instrument for the Very Large Telescope Interferometer (VLTI) is expected to be the first nuller to observe young giant exoplanets. The Large Interferometer For Exoplanets (LIFE) project aims at implementing long-baseline nulling interferometry in space to image and characterize Earth-like exoplanets. LIFE requires to reach deep ($<10^{-5}$) null depths over a large bandwidth in the mid-infrared (MIR: 4-18.5$\,μ$m) with a high throughput ($>15\,\%$). These requirements are necessary to detect and characterize the thermal emission of Earth-like exoplanets. To achieve deep null depths, a spatial filter is necessary to wash away the wavefront aberrations that would otherwise be a limiting factor for the contrast. However, efficient spatial filtering with high throughput ($>95\,\%$) is challenging to achieve over such a large bandwidth. In this study, we explore the possibility of broadband spatial filtering using two step-index fib
We used the Webots robotics simulation platform to simulate a dyadic avoiding and mobbing predator behavior in a group of Braitenbergian robots. Mobbing is an antipredator adaptation used by some animals in which the individuals cooperatively attack or harass a predator to protect themselves. One way of coordinating a mobbing attack is using mobbing calls to summon other individuals of the mobbing species. We imitated this mechanism and simulated Braitenbergian robots that use mobbing calls when they face a light source (representing an inanimate predator) and mob it if they can summon allies, otherwise, they escape from it. We explore the effects of range of mobbing call (infinite range, mid-range and low-range) and the size of the robot group (ten robots vs three) on the overall success of mobbing. Our results suggest that both variables have significant impacts. This work has implications for simulations of action selection in artificial life and designing control architectures for autonomous agents.
We investigate how well the Large Interferometer for Exoplanets (LIFE) mission concept can detect habitable conditions on exoplanets through the presence of atmospheric water vapor as a proxy for surface oceans. We model the atmosphere of a pre-biotic Earth-like planet across a range of water concentrations, from water-poor to water-rich, with surface partial pressures from 10$^{-7}$ to 1 bar of H$_2$O. We simulate LIFE-like noise at spectral resolutions R = 50 and 100 using LIFEsim and perform Bayesian atmospheric retrievals to determine the technical requirements for LIFE to confirm habitability. We model three vertical water distributions: a vertically constant profile, a Manabe-Wetherald based Earth-like profile, and a diffusion and photochemistry profile to test how the assumed vertical structure influences the retrieved abundances. Clouds are not modeled. We find the ability for LIFE to detect water strongly depends on the vertical profile assumed. LIFE is unable to constrain the highest water cases and provides upper limits on low water planets. For the highest water abundances, absorption features saturate and reduce sensitivity to characterize precise H$_2$O levels. Water
Mid-infrared hyperspectral imaging has become an indispensable tool to spatially resolve chemical information in a wide variety of samples. However, acquiring three-dimensional data cubes is typically time-consuming due to the limited speed of raster scanning or wavelength tuning, which impedes real-time visualization with high spatial definition across broad spectral bands. Here, we devise and implement a high-speed, wide-field mid-infrared hyperspectral imaging system relying on broadband parametric upconversion of high-brightness supercontinuum illumination at the Fourier plane. The upconverted replica is spectrally decomposed by a rapid acousto-optic tunable filter, which records high-definition monochromatic images at a frame rate of 10 kHz based on a megapixel silicon camera. Consequently, the hyperspectral imager allows us to acquire 100 spectral bands over 2600-4085 cm$^{-1}$ in 10 ms, corresponding to a refreshing rate of 100 Hz. Moreover, the angular dependence of phase matching in the image upconversion is leveraged to realize snapshot operation with spatial multiplexing for multiple spectral channels, which may further boost the spectral imaging rate. The high acquisiti
A key goal of astronomers with the next generation telescopes is to detect signs of life in exoplanet atmospheres. NASA's next flagship is the Habitable Worlds Observatory (HWO). In the context of ESA's Voyage 2050 program, the Senior Committee report prioritises detecting habitable exoplanet atmospheres in the mid-IR. The most suited mission for this is the Large Interferometer for Exoplanets (LIFE) which can detect an even wider range of biosignatures than HWO and at lower concentrations. LIFE is a global science collaboration based out of ETH Zürich. With the UK's expertise in building infrared instruments we could play a leading role in realising an ambitious European-led mission. Notably, LIFE is able to detect necessary planetary context like surface temperature and pressure, along with a key discriminator molecule for biosignature false positives, methane, which will be much harder or impossible with HWO. Also, LIFE will be able to investigate many of the nearby rocky exoplanets known from radial velocity searches that are inaccessible to HWO due to its limited spatial resolution.
Active mid-infrared (MIR) imagers capable of retrieving three-dimensional (3D) structure and reflectivity information are highly attractive in a wide range of biomedical and industrial applications. However, the infrared 3D imaging at low-light levels is still challenging due to the deficiency of sensitive and fast MIR sensors. Here we propose and implement a MIR time-of-flight imaging system that operates at single-photon sensitivity and femtosecond timing resolution. Specifically, back-scattered infrared photons from a scene are optically gated by delay-controlled ultrashort pump pulses through nonlinear frequency upconversion. The upconverted images with time stamps are then recorded by a silicon camera to facilitate the 3D reconstruction with high lateral and depth resolutions. Moreover, an effective numerical denoiser based on spatiotemporal correlation allows us to reveal the object profile and reflectivity under photon-starving conditions with a detected flux below 0.05 photons/pixel/second. The presented MIR 3D imager features with high detection sensitivity, precise timing resolution, and wide-field operation, which may open new possibilities in life and material sciences.
The oxidation state of rocky exoplanets is expected to play a fundamental role in shaping the chemical composition of their secondary atmospheres by influencing the chemical composition of volcanically released gasses. Distinguishing planetary redox states through direct atmospheric characterization would offer insight into the formation and evolution of secondary atmospheres on exoplanets and inform the background chemistry of putative biosignatures. The Large Interferometer For Exoplanets (LIFE) mission concept aims to employ a space-based mid-infrared nulling interferometer to characterize exoplanetary atmospheres. In this work, we assess LIFE's performance in distinguishing the redox states of rocky exoplanets by direct spectroscopic measurements. We focus on the observability and spectral features of redox-sensitive molecules in secondary atmospheres of Earth-sized exoplanets. We develop and apply a retrieval framework based on the ARtful modeling Code for exoplanet Science (ARCiS) and the LIFE mission simulator (LIFEsim) to simulate observations of Earth-sized planets with atmospheres from a range of plausible mantle redox conditions. Our simulations show that LIFE in its bas
Future telescopes such as the Large Interferometer For Exoplanets (LIFE) will enable mid-infrared characterisation of the atmospheres of nearby rocky exoplanets. Whilst 4D spatial and temporal variations of Earth as an exoplanet are below spectroscopic detection limits, such variability is planet-specific. We investigate LIFE's ability to detect 4D variability in the atmospheres of tidally locked exoplanets. We create daily synthetic LIFE observations of Proxima Centauri b in a 1:1 and an eccentric 3:2 spin-orbit resonance (SOR), using LIFEsim on spectra from daily 3D climate-chemistry model output of an aquaplanet with Earth-like composition. Hemispheric distributions of temperature, clouds, and chemical species determine spectral signatures and variability with orbital phase angle. Such variability dictates the extent to which parameters can be reliably inferred from snapshot spectra at arbitrary viewing geometries. In the 1:1 SOR, MIR spectra vary significantly with viewing geometry and indirectly probe atmospheric circulation. Nightside temperature inversions generate O3, CO2, and H2O emission features, though these lie below LIFE's detection threshold, and instead O3 features
In our search for life beyond the Solar System, certain planetary bodies may be more conducive to life than Earth. However, the observability of these `superhabitable' planets in the habitable zones around K dwarf stars has not been fully modeled. This study addresses this gap by modeling the atmospheres of superhabitable exoplanets. We employed the 1D model $\texttt{Atmos}$ to define the superhabitable parameter space, $\texttt{POSEIDON}$ to calculate synthetic transmission spectra, and $\texttt{PandExo}$ to simulate $\text{JWST}$ observations. Our results indicate that planets orbiting mid-type K dwarfs, receiving $80\%$ of Earth's solar flux, are optimal for life. These planets sustain temperate surfaces with moderate $CO_2$ levels, unlike those receiving $60\%$ flux, where necessarily higher $CO_2$ levels could hinder biosphere development. Moreover, they are easier to observe, requiring significantly fewer transits for biosignature detection compared to Earth-like planets around Sun-like stars. For instance, detecting biosignature pairs like oxygen and methane from $30$ parsecs would require $150$ transits ($43$ years) for a superhabitable planet, versus over $1700$ transits (
We present a multiwavelength catalog of mid-infrared-selected compact sources in 19 nearby galaxies, combining JWST NIRCam/MIRI, HST UV-optical broadband, H$α$ narrow-band, and ALMA CO observations. We detect 24,945 compact sources at 21 $μ$m and 55,581 at 10 $μ$m. Artificial star tests show 50% completeness limits of $\sim$5 $μ$Jy for the 10 $μ$m catalog, and $\sim$24 $μ$Jy for the 21 $μ$m catalog. We find that 21 $μ$m compact sources contribute $\sim$20% of the total galaxy emission in that band, but only contribute $5%$ at 10 $μ$m. We classify sources using stellar evolution and population synthesis models combined with empirical classifications derived from the literature. Our classifications include H$α$-bright and dust-embedded optically faint clusters, red supergiants (RSGs), oxygen-rich and carbon-rich AGB stars, and a range of rarer stellar types. In sampling a broad range of star forming environments with a uniform, well-characterized selection, this catalog enables enables analyses of infrared-bright stellar populations. We find that H$α$-faint sources account for only 10% of dusty (likely young) clusters, implying that the infrared-bright, optically-faint phase of clust
The Mars Life Explorer (MLE) mission concept offers a critical opportunity to investigate whether extant life exists within the mid-latitude ice deposits of Mars. However, MLE's current science traceability matrix emphasizes habitability assessment and organic chemistry over direct life detection. As crewed missions to Mars may occur as early as 2040, the window for uncontaminated robotic exploration is rapidly closing. A high-confidence determination of Martian life must be achieved before irreversible anthropogenic contamination compromises scientific integrity. This paper evaluates the scientific, technical, and policy limitations of the current MLE architecture and recommends specific instrumentation upgrades and governance measures necessary to enable definitive and agnostic life detection while safeguarding planetary protection.
The search for potentially habitable exoplanets centers on detecting biosignature molecules in Earth-like atmospheres, which makes it essential to understand their detectability under biologically and geologically influenced conditions. In this study, we model the reflection and thermal emission spectra of such atmospheres across the UV/VIS/NIR and mid-IR regions and simulate their detectability with future mission concepts such as the Habitable Worlds Observatory (HWO) and the Large Interferometer for Exoplanets (LIFE). We employ Numerical Weather Prediction (NWP) model data, based on Earth's atmosphere, to derive temperature pressure profiles and couple them with a 1D photochemical model to assess the detectability of these molecules in Earth analogs located 10 parsecs away. We investigate the dominant reaction pathways and their contributions to the atmospheric composition of an Earth analog, with a focus on how they shape the resulting molecular signatures. We also examine the role of surface boundary conditions, which indirectly trace the effects of biological and geological processes, on the detectability of these molecules using HWO- and LIFE-type mission concepts. Our findi
Following the recommendations to NASA and ESA, the search for life on exoplanets will be a priority in the next decades. Two direct imaging space mission concepts are being developed: the Habitable Worlds Observatory (HWO) and the Large Interferometer for Exoplanets (LIFE). HWO focuses on reflected light spectra in the ultraviolet/visible/near-infrared (UV/VIS/NIR), while LIFE captures the mid-infrared (MIR) emission of temperate exoplanets. We assess the potential of HWO and LIFE in characterizing a cloud-free Earth twin orbiting a Sun-like star at 10 pc, both separately and synergistically, aiming to quantify the increase in information from joint atmospheric retrievals on a habitable planet. We perform Bayesian retrievals on simulated data from an HWO-like and a LIFE-like mission separately, then jointly, considering the baseline spectral resolutions currently assumed for these concepts and using two increasingly complex noise simulations. HWO would constrain H$_2$O, O$_2$, and O$_3$, in the atmosphere, with ~ 100 K uncertainty on the temperature profile. LIFE would constrain CO$_2$, H$_2$O, O$_3$ and provide constraints on the thermal atmospheric structure and surface temperatu
This study aims to identify exemplary science cases for observing N$_2$O, CH$_3$Cl, and CH$_3$Br in exoplanet atmospheres at abundances consistent with biogenic production using a space-based mid-infrared nulling interferometric observatory, such as the LIFE (Large Interferometer For Exoplanets) mission concept. We use a set of scenarios derived from chemical kinetics models that simulate the atmospheric response of varied levels of biogenic production of N$_2$O, CH$_3$Cl and CH$_3$Br in O$_2$-rich terrestrial planet atmospheres to produce forward models for our LIFEsim observation simulator software. In addition we demonstrate the connection to retrievals for selected cases. We use the results to derive observation times needed for the detection of these scenarios and apply them to define science requirements for the mission. Our analysis shows that in order to detect relevant abundances with a mission like LIFE in it's current baseline setup, we require: (i) only a few days of observation time for certain very near-by "Golden Target" scenarios, which also motivate future studies of "spectral-temporal" observations (ii) $\sim$10 days in certain standard scenarios such as temperate
We presents an approach for early cycle classification of lithium-ion batteries into high and low-performing categories, coupled with the prediction of their remaining useful life (RUL) using a linear lasso technique. Traditional methods often rely on extensive cycling and the measurement of a large number of electrochemical impedance spectroscopy (EIS) frequencies to assess battery performance, which can be time and resource consuming. In this study, we propose a methodology that leverages specific EIS frequencies to achieve accurate classification and RUL prediction within the first few cycles of battery operation. Notably, given only the 20 kHz impedance response, our support vector machine (SVM) model classifies batteries with 100\% accuracy. Additionally, our findings reveal that battery performance classification is frequency agnostic within the high frequency ($<20$ kHz) to low-frequency (32 mHz) range. Our model also demonstrates accurate RUL predictions with $R^2>0.96$ based on the out of phase impedance response at a single high (20 kHz) and a single mid-frequency (8.8 Hz), in conjunction with temperature data. This research underscores the significance of the mid-f
We present the database of potential targets for the Large Interferometer For Exoplanets (LIFE), a space-based mid-infrared nulling interferometer mission proposed for the Voyage 2050 science program of the European Space Agency (ESA). The database features stars, their planets and disks, main astrophysical parameters, and ancillary observations. It allows users to create target lists based on various criteria to predict, for instance, exoplanet detection yields for the LIFE mission. As such, it enables mission design trade-offs, provides context for the analysis of data obtained by LIFE, and flags critical missing data. Work on the database is in progress, but given its relevance to LIFE and other space missions, including the Habitable Worlds Observatory (HWO), we present its main features here. A preliminary version of the LIFE database is publicly available on the German Astrophysical Virtual Observatory (GAVO).