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We study the implications of relaxing the requirement for ultralight axions to account for all dark matter in the Universe by examining mixed dark matter (MDM) cosmologies with axion fractions |$f \le 0.3$| within the fuzzy dark matter window |$10^{-25}$|  eV |$\lesssim m \lesssim 10^{-23}$|  eV. Our simulations, using a new MDM gravity solver implemented in AxiREPO , capture wave dynamics across various scales with high accuracy down to redshifts |$z\approx 1$|⁠. We identify haloes with Rockstar using the cold dark matter component and find good agreement of inferred halo mass functions and concentration–mass relations with theoretical models across redshifts |$z=1{\!-\!}10$|⁠. This justifies our halo finder approach a posteriori as well as the assumptions underlying the MDM halo model AxionHMcode. Using the inferred axion halo mass–cold halo mass relation |$M_{\text{a}}(M_{\text{c}})$| and calibrating a generalized smoothing parameter |$\alpha$| to our MDM simulations, we present a new version of AxionHMcode. The code exhibits excellent agreement with simulations on scales |$k\lt 20 \, h \, \text{cMpc}^{-1}$| at redshifts |$z=1{\!-\!}3.5$| for |$f\le 0.1$| around the fiducial axion mass |$m = 10^{-24.5}\, \text{eV} = 3.16\times 10^{-25}\, \text{eV}$|⁠ , with maximum deviations remaining below 10 per cent. For axion fractions |$f\le 0.3$|⁠ , the model maintains accuracy with deviations under 20 per cent at redshifts |$z\approx 1$| and scales |$k\lt 10 \, h \, \text{cMpc}^{-1}$|⁠ , though deviations can reach up to 30 per cent for higher redshifts when |$f=0.3$|⁠. Reducing the run-time for a single evaluation of AxionHMcode to below 1 min, these results highlight the potential of AxionHMcode to provide a robust framework for parameter sampling across MDM cosmologies in Bayesian constraint and forecast analyses. [ABSTRACT FROM AUTHOR]

Along the lower course of the Rioni and several minor rivers, more than 70 settlement mounds (local name: Dikhagudzuba) have been identified by field surveys and remote sensing techniques. They give evidence of a formerly densely populated landscape in the coastal lowlands on the Colchian plain (western Georgia) and have been dated to the Bronze Age. As yet, limited information is available on their internal architecture, the chronology of the different layers and their palaeoenvironmental context. Based on archaeological sources, remote sensing measurements of three mounds and sediment cores from one mound and its closer surroundings, our study presents a review of the relevant literature and reveals the internal structure, distribution and spatial extent of the mounds. Geochemical and sedimentological analyses of element contents (X‐ray fluorescence) and granulometry helped to identify different stratigraphical layers and differentiate between natural facies and anthropogenic deposits; using the Structure‐from‐Motion technique the mounds' dimensions were calculated. The studied settlement mounds had relatively small dimension (varying from 30 to 100 m in diameter) and were similar in their stratigraphy. Measurement of elements that can identify types of human activity, notably metals and phosphorus, suggest changing intensities of human occupation, pastoral agriculture and metalworking through the occupation sequence. According to the 14C chronology, the formation of the settlements occurred during the first half of the second millennium B.C., which confirms the archaeological interpretation of their Bronze Age origin. The narrow age difference between the lowermost and uppermost anthropogenic layers indicates an intentional construction of the mounds, rather than a successive accumulation of construction debris due to the disintegration of loam bricks by weathering. Therefore, they are indeed mounds and not tells. It is most likely that the characteristic circular moats that surround them were the source of their construction material. Fluvial and alluvial processes in a warm and humid climate dominated the environment of the mounds. [ABSTRACT FROM AUTHOR]

Soils in hyper‐arid climates, such as the Chilean Atacama Desert, show indications of past and present forms of life despite extreme water limitations. We hypothesize that fog plays a key role in sustaining life. In particular, we assume that fog water is incorporated into soil nutrient cycles, with the inland limit of fog penetration corresponding to the threshold for biological cycling of soil phosphorus (P). We collected topsoil samples (0–10 cm) from each of 54 subsites, including sites in direct adjacency (<10 cm) and in 1 m distance to plants, along an aridity gradient across the Coastal Cordillera. Satellite‐based fog detection revealed that Pacific fog penetrates up to 10 km inland, while inland sites at 10–23 km from the coast rely solely on sporadic rainfall for water supply. To assess biological P cycling we performed sequential P fractionation and determined oxygen isotope of HCl‐extractable inorganic Pδ18OHCl−Pi$$ \mathrm{P}\ \left({\updelta}^{18}{\mathrm{O}}_{\mathrm{HCl}-{\mathrm{P}}_{\mathrm{i}}}\right) $$. Total P (Pt) concentration exponentially increased from 336 mg kg−1 to a maximum of 1021 mg kg−1 in inland areas ≥10 km. With increasing distance from the coast, soil δ18OHCl−Pi$$ {\updelta}^{18}{\mathrm{O}}_{\mathrm{HCl}-{\mathrm{P}}_{\mathrm{i}}} $$ values declined exponentially from 16.6‰ to a constant 9.9‰ for locations ≥10 km inland. Biological cycling of HCl‐Pi near the coast reached a maximum of 76%–100%, which could only be explained by the fact that fog water predominately drives biological P cycling. In inland regions, with minimal rainfall (<5 mm) as single water source, only 24 ± 14% of HCl‐Pi was biologically cycled. We conclude that biological P cycling in the hyper‐arid Atacama Desert is not exclusively but mainly mediated by fog, which thus controls apatite dissolution rates and related occurrence and spread of microbial life in this extreme environment. [ABSTRACT FROM AUTHOR]

Fuzzy dark matter (FDM) is a dark matter candidate consisting of ultralight scalar particles with masses around |$10^{-22}\, \mathrm{eV}/c^2$|⁠ , a regime where cold bosonic matter behaves as a collective wave rather than individual particles. Although constraints on FDM are accumulating in many different contexts, very few have been verified by self-consistent numerical simulations. We present new large numerical simulations of cosmic structure formation with FDM, solving the full Schrödinger–Poisson (SP) equations using the AxiREPO code, which implements a pseudo-spectral numerical method. Combined with our previous simulations, they allow us to draw a four-way comparison of matter clustering, contrasting results (such as power spectra) for each combination of initial conditions (ICs; FDM versus cold dark matter, CDM) and dynamics (SP versus N -body). By disentangling the impact of ICs and non-linear dynamics in this manner, we can gauge the validity of approximate methods used in previous works, such as ordinary N -body simulations with an FDM initial power spectrum. Due to the comparatively large volume achieved in our FDM simulations, we are able to measure the FDM halo mass function from full wave simulations for the first time, and compare to previous results obtained using analytic or approximate approaches. We also investigate the density profiles of these filaments and compare to their ΛCDM counterparts. [ABSTRACT FROM AUTHOR]

Using a single gravitational lens system observed at ≲ 5 mas resolution with very long baseline interferometry, we place a lower bound on the mass of the fuzzy dark matter (FDM) particle, ruling out m χ ≤ 4.4 × 10−21 eV with a 20:1 posterior odds ratio relative to a smooth lens model. We generalize our result to non-scalar and multiple-field models, such as vector FDM, with m χ,vec > 1.4 × 10−21 eV. Due to the extended source structure and high angular resolution of the observation, our analysis is directly sensitive to the presence of granule structures in the main dark matter halo of the lens, which is the most generic prediction of FDM theories. A model based on well-understood physics of ultra-light dark matter fields in a gravitational potential well makes our result robust to a wide range of assumed dark matter fractions and velocity dispersions in the lens galaxy. Our result is competitive with other lower bounds on m χ from past analyses, which rely on intermediate modelling of structure formation and/or baryonic effects. Higher resolution observations taken at 10–100 GHz could improve our constraints by up to two orders of magnitude in the future. [ABSTRACT FROM AUTHOR]

A complete annual cycle of the dynamics of fine-grained sediment supplied by the Omo and smaller rivers is simulated for Lake Turkana, one of the world's large lakes, with the hydrodynamic, wave and sediment transport model Delft3D. The model is forced with river liquid and solid discharge and wind data in order to simulate cohesive sediment transport and resuspension. It simulates stratification due to salinity, wave generation and dissipation, and sediment advection and resuspension by waves and currents, with multiple cohesive sediment fractions. A comparison of the simulation results with remotely-sensed imagery and with available in-situ sediment deposition rates validates the model. By devising simulation scenarios in which certain processes were switched on or off, we investigated the contribution of waves, wind-induced surface and bottom currents, salinity-induced stratification and river jet, in resuspending and transporting fine sediments in the lake basin. With only the wind or river influence, most of the sediment deposition occurs in the first 10 km off the Omo River mouth and at a depth < 10 m. When waves are switched on, increased bed shear stresses resuspend most of the fine sediments, that are then deposited further and deeper in the first 30 km, in water depths > 30 m. This study sheds new light on sediment transport in Lake Turkana and in great lakes in general, favouring the view that wind-waves can be the main agent that transports sediment away from river mouths and to deeper areas, as opposed to river-plume or gravity-driven transport. [ABSTRACT FROM AUTHOR]

Phoenicians were the first to systematically develop the area surrounding the Strait of Gibraltar at the end of the 9th century B.C. Following pioneering studies in the Río Guadiaro estuary (Málaga/Cádiz) in the 1980s, a German‐Spanish cooperation project focussed on the role of indigenous people in the Phoenician colonisation trading networks at Los Castillejos de Alcorrín (Manilva, Málaga), one of the most important Early Iron Age settlements in southwestern Iberia. In the recent past, combined with systematic archaeological surveys, geoarchaeological research embedded in the interdisciplinary project 'Archeostraits' aimed at (i) deciphering palaeoenvironmental and coastal changes in the surroundings of Los Castillejos de Alcorrín throughout the mid‐ to late Holocene; (ii) constraining palaeoenvironmental conditions during early Phoenician colonisation; and (iii) better understanding human–environment interactions during the Final Bronze and Early Iron Age (i.e., end of 9th and 8th centuries B.C.). Coring transects along the Río Guadiaro allowed for differentiating successive palaeoenvironments and for establishing a chrono‐stratigraphy for the Holocene sedimentary infill of the valley. Based on these results, the deposition of shallow marine sands, overlying deltaic deposits of alternating sand and mud, and the subsequent development of lagoonal conditions in the lower Guadiaro valley took place before the Phoenicians established the first settlements along the coast. [ABSTRACT FROM AUTHOR]

In the fuzzy dark matter (FDM) model, gravitationally collapsed objects always consist of a solitonic core located within a virialized halo. Although various numerical simulations have confirmed that the collapsed structure can be described by a cored Navarro–Frenk–White-like density profile, there is still disagreement about the relation between the core mass and the halo mass. To fully understand this relation, we have assembled a large sample of cored haloes based on both idealized soliton mergers and cosmological simulations with various box sizes. We find that there exists a sizeable dispersion in the core–halo mass relation that increases with halo mass, indicating that the FDM model allows cores and haloes to coexist in diverse configurations. We provide a new empirical equation for a core–halo mass relation with uncertainties that can encompass all previously found relations in the dispersion, and emphasize that any observational constraints on the particle mass m using a tight one-to-one core–halo mass relation should suffer from an additional uncertainty of the order of 50  per cent for halo masses |${\gtrsim} 10^9 \, [8\times 10^{-23} \, \mathrm{eV}/(mc^2)]^{3/2} \, \mathrm{M}_\odot$|⁠. We suggest that tidal stripping may be one of the effects contributing to the scatter in the relation. [ABSTRACT FROM AUTHOR]

An ultralight bosonic particle of mass around |$10^{-22}\, \mathrm{eV}/c^2$| is of special interest as a dark matter candidate, as it both has particle physics motivations, and may give rise to notable differences in the structures on highly non-linear scales due to the manifestation of quantum-physical wave effects on macroscopic scales, which could address a number of contentious small-scale tensions in the standard cosmological model, ΛCDM. Using a spectral technique, we here discuss simulations of such fuzzy dark matter (FDM), including the full non-linear wave dynamics, with a comparatively large dynamic range and for larger box sizes than considered previously. While the impact of suppressed small-scale power in the initial conditions associated with FDM has been studied before, the characteristic FDM dynamics are often neglected; in our simulations, we instead show the impact of the full non-linear dynamics on physical observables. We focus on the evolution of the matter power spectrum, give first results for the FDM halo mass function directly based on full FDM simulations, and discuss the computational challenges associated with the FDM equations. FDM shows a pronounced suppression of power on small scales relative to cold dark matter (CDM), which can be understood as a damping effect due to 'quantum pressure'. In certain regimes, however, the FDM power can exceed that of CDM, which may be interpreted as a reflection of order-unity density fluctuations occurring in FDM. In the halo mass function, FDM shows a significant abundance reduction below a characteristic mass scale only. This could in principle alleviate the need to invoke very strong feedback processes in small galaxies to reconcile ΛCDM with the observed galaxy luminosity function, but detailed studies that also include baryons will be needed to ultimately judge the viability of FDM. [ABSTRACT FROM AUTHOR]

In southern Iberia, the surroundings of the Strait of Gibraltar are known as a crossroad for population movements, cultural exchanges, and trade from Late Prehistory to modern times. However, questions remain about the impact of this historical development on the environment. The settlement of La Silla del Papa, an important hillfort in southern Andalusia (Cádiz), was occupied during the entire Iron Age, replaced by the coastal town Baelo Claudia during Roman times, and re‐occupied during Early Medieval times. As such, La Silla del Papa and its territory represent an ideal location for long‐term studies on human‐environment interactions. Within the framework of the interdisciplinary project "Archeostraits," geoarchaeological investigations in the surroundings of La Silla del Papa aimed at constraining ecological conditions and human‐environment interactions during the mid‐ and late Holocene and during major human occupation phases. Our results document an early mid‐Holocene marine embayment in the lower floodplain of the Río del Cachón, rapidly turning into a coastal lagoon and later into freshwater‐dominated wetlands. After approximately 2100 BP (c. 150 BC), fluvial and alluvial deposition i600ing a high anthropogenic impact on the local landscape during Roman or post‐Roman times. Palynological results reveal fluctuating agricultural and pastoral activities and distinct periods of landscape opening during the Neolithic and Iron Age. [ABSTRACT FROM AUTHOR]

Wave-transported boulders represent important records of storm and tsunami impact over geological timescales. Their use for hazard assessment requires chronological information on their displacement that in many cases cannot be achieved by established dating approaches. To fill this gap, this study investigated, for the first time, the potential of optically stimulated luminescence rock surface exposure dating (OSL-RSED) for estimating cliff-detachment ages of wave-transported coastal boulders. The approach was tested on calcarenite clasts at the Rabat coast, Morocco. Calibration of the OSL-RSED model was based on samples with rock surfaces exposed to sunlight for ∼ 2 years, and OSL exposure ages were evaluated against age control deduced from satellite images. Our results show that the dating precision is limited for all targeted boulders due to the local source rock lithology which has low amounts of quartz and feldspar. The dating accuracy may be affected by erosion rates on boulder surfaces of 0.02–0.18 mm yr -1. Nevertheless, we propose a robust relative chronology for boulders that are not affected by significant post-depositional erosion and that share surface angles of inclination with the calibration samples. The relative chronology indicates that (i) most boulders were detached from the cliff by storm waves; (ii) these storms lifted boulders with masses of up to ∼ 24 t; and (iii) the role of storms in the formation of boulder deposits along the Rabat coast is more significant than previously assumed. Although OSL-RSED cannot provide reliable absolute exposure ages for the coastal boulders in this study, the approach has large potential for boulder deposits composed of rocks with larger amounts of quartz or feldspar and less susceptibility to erosion. [ABSTRACT FROM AUTHOR]

Chronostratigraphic investigations on coastal sedimentary records such as washover fans or beach‐ridge sequences may be used to reconstruct storm chronologies on centennial to millennial time scales. However, modern analogs are pivotal in interpreting depositional processes and reducing uncertainty in evaluating the complex chronostratigraphic architecture of these landforms. Such a modern analog was provided by category 3 tropical cyclone (TC) Olwyn in 2015, which caused a significant storm surge in the Exmouth Gulf (Western Australia). Pre‐ and post‐TC Olwyn geomorphological surveys and high‐resolution drone‐derived topographical data of a large washover fan document a detailed history of erosion and deposition during the event. The modern analog deposits provided an excellent opportunity to evaluate the use of luminescence‐based proxies (luminescence inventories) for tracing event‐related sediment source environments and understanding transport processes. Sediments deposited during Olwyn show a systematic relationship between luminescence characteristics and washover fan position. Seaward and central washover sections are indicated by well‐bleached deposits due to the beach as the dominant source and/or long transport distances. Lateral washover deposits are characterized by rather local source areas and short transport distances, resulting in higher remnant ages of 70–140 a. Our data show that the combination of sediment source environments and sediment transport length across the fan represents the main control in resetting the luminescence signal and enabling reliable depositional ages to be calculated. It documents the benefit of investigating luminescence inventories when establishing chronologies from complex sedimentary records, thereby demanding a careful consideration of local processes and source areas when interpreting sedimentary TC records. Key Points: We investigated deposits of tropical cyclone Olwyn by combining drone‐derived digital elevation models and single grain luminescence dataHigh‐resolution pre‐ and post‐TC Olwyn DEMs helped to quantify the complex pattern of erosion and deposition in a large washover fanThe single grain luminescence data revealed differences in sediment source areas and transport distances of the washover deposits [ABSTRACT FROM AUTHOR]

In the southernmost part of the Colchian plain (Georgia), the Supsa and Rioni rivers represent important catchments for reconstructing Holocene landscape changes. Using granulometric methods, geochemical analyses and radiocarbon dating, we demonstrate that significant palaeoenvironmental changes have taken place in the surroundings of the Supsa fan since at least 4000 BCE. The initial foothill fan accumulation was prolonged by delta plain progradation. Due to continued fluvial sediment supply, mainly from the Rioni, the lagoon silted up and extended peat bogs formed east of the beach ridge complex. The Supsa fan first prograded northwards (since the third millennium BCE) and later shifted westwards, eventually following an avulsion of the Rioni. While Supsa deposits remain limited to the area of the fan and the modern estuary, the alluvial fines of the Rioni dominate the surrounding areas. The relative sea-level (RSL) index points of the region suggest a gradual RSL rise from ∼-9 m between 4000 and 3500 BCE to -3 / -2 m below the modern sea level in the second half of the first millennium BCE, the period during which Greek colonization and Colchian settlements are attested by archaeological remains. Kurzfassung: Im südlichsten Teil der kolchischen Tiefebene (Georgien) stellen die Einzugsgebiete von Rioni und Supsa wichtige Areale zur Rekonstruktion des holozänen Landschaftswandels dar. Mittels granulometrischer und geochemischer Analysen sowie Radiokohlenstoffdatierungen lässt sich der signifikante Landschaftswandel im Bereich des Supsa-Schwemmfächers seit etwa 4000 v. Chr. nachweisen. Das Areal wurde von einer Sandbarre vom offenen Meer getrennt, hinter der sich große Stillwasserbereiche bildeten. Der anhaltende fluviale Sedimenteintrag, hauptsächlich durch den Rioni, begünstigte die allmähliche Verlandung und die Entstehung von Torfmooren. Gleichzeitig baute sich – zunächst nach Norden (etwa ab dem 3. Jahrtausend v. Chr.) und später durch den Rioni nach Westen abgelenkt – der Schwemmfächer des Supsa vor. Während sich die Supsa-Ablagerungen im Wesentlichen auf den Schwemmfächer und die aktuelle Mündung beschränken, dominieren die feinkörnigen Ablagerungen des Rioni die Umgebung. Die Indexpunkte für den relativen Meeresspiegel deuten auf einen anhaltenden Anstieg des Meeres hin, ausgehend von etwa -9 m unter dem heutigen Niveau um 4000 bis 3500 v. Chr. auf -3 bis -2 m in der zweiten Hälfte des 1. Jahrtausends v. Chr. Für den letztgenannten Zeitraum sind kolchische und griechische Siedlungen durch archäologische Funde in der Umgebung der Supsa-Mündung belegt. [ABSTRACT FROM AUTHOR]