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On fully intuitionistic fuzzy linear fractional programming via novel parameterized membership functions with application in portfolio optimization
No full textFractional programming is an extensively used technique to simultaneously deal with two conflicting objectives, by optimizing their ratio. This paper focuses on fully intuitionistic fuzzy fractional programming to address real-world problems. Firstly, the intuitionistic fuzzy model is converted into a crisp multi-objective problem with fractional objectives. Subsequently, a novel intuitionistic fuzzy programming approach is proposed, offering an insightful method for selecting least acceptable values. The existing literature on intuitionistic fuzzy programming employs linear, exponential, hyperbolic, or parabolic membership and non-membership functions. This article presents that these functions result in a highly restrictive feasibility region. Thus, a family of parameterized membership and non-membership functions is introduced, which overcomes the limitations of conventionally used functions and effectively captures both the acceptance as well as rejection degrees. In this article, theoretical foundations are established for the proposed technique through several theorems which have been constructed and proved. Additionally, the proposed technique is illustrated through a numerical example and applied to a real-life portfolio optimization problem, demonstrating its effectiveness. Finally, a comparative analysis with prevalent studies is also conducted to emphasize the versatile nature of the proposed functions
Implications of dual-purpose concerns and power dynamics in green supply chains
No full textThis study investigates the dynamic interplay between dual-purpose concerns, integrating social responsibility with profit objectives, and green investment efficiency within green supply chains using a game-theoretical approach. These factors are examined in different configurations: Retailer Stackelberg (RS), Manufacturer Stackelberg (MS), and Vertical Nash (VN). Research results show that dual-purpose concerns generally improve both environmental efforts and overall profitability, but their effects vary depending on the supply chain structure. In the RS structure, the manufacturer’s dual-purpose concerns lead to better environmental and economic outcomes, while in MS and VN, the retailer’s concerns drive better results. Additionally, being the first to set prices is not always beneficial. For instance, when green investments are highly effective, the retailer prefers to follow the manufacturer’s lead. As investment efficiency drops, the retailer favors simultaneous decision-making or even taking the lead. For manufacturers, the MS structure is best if they prioritize profits. However, if they also care about social responsibility, their preferred role changes based on green investment efficiency and the level of dual-purpose concern, sometimes favoring leadership and other times a follower position or simultaneous decision-making. Furthermore, two extensions are examined: one considers the scenario in which both firms exhibit dual-purpose concerns, and the other explores a variable marginal production cost setting
Environmental DNA (eDNA) sampling strategies influence estimates of lake fish eDNA concentrations
No full textEnvironmental DNA (eDNA) is increasingly used to estimate species abundance and biomass, but impacts of sampling strategies are poorly understood. We compared point and spatially integrated sampling, two commonly used sampling strategies, in two lakes using quantitative eDNA analysis. Integrated sampling increases the spatial coverage and the total volume of water sampled relative to point sampling. However, integrated sampling led to lower fish eDNA recovery and underestimated eDNA concentrations compared to point sampling. Although the exact mechanisms underlying this pattern require further investigation, these results underscore the importance of aligning sampling strategies with key study objectives
Millimeter-wave observations of Euclid Deep Field South using the South Pole Telescope
No full textContext. The South Pole Telescope third-generation camera (SPT-3G) has observed over 10 000 square degrees of sky at 95, 150, and 220 GHz (3.3, 2.0, 1.4 mm, respectively) and will significantly overlap the ongoing 14 000 square-degree Euclid Wide Survey. The Euclid collaboration recently released Euclid Deep Field South (EDF-S) observations of 23 square degrees at wide field depths in the first quick data release (Q1).
Aims. With the goal of releasing complementary millimeter-wave data and encouraging legacy science, we performed dedicated observations of a 57-square-degree field overlapping the EDF-S.
Methods. The observing time totaled 20 days, and we reached noise depths of 4.3, 3.8, and 13.2 μK-arcmin at 95, 150, and 220 GHz, respectively.
Results. In this work we present the temperature maps and two catalogs constructed from these data. The emissive source catalog contains 601 objects (334 inside EDF-S) with 54% synchrotron-dominated sources and 46% thermal dust emission-dominated sources. The 5σ detection thresholds are 1.7, 2.0, and 6.5 mJy in the three bands. The cluster catalog contains 217 cluster candidates (121 inside EDF-S) with median mass M500c = 2.12 × 1014 M⊙/h70 and median redshift z = 0.70, corresponding to an order-of-magnitude improvement in cluster density over previous tSZ-selected catalogs in this region (3.81 clusters per square degree).
Conclusions. The overlap between SPT and Euclid data will enable a range of multiwavelength studies of the aforementioned source populations. This work serves as the first step toward joint projects between SPT and Euclid and provides a rich dataset containing information on galaxies, clusters, and their environments
Heavy-element-enriched atmospheres and where they are born
No full textThe heavy element content of giant exoplanets, inferred from structure models based on their radius and mass, often exceeds predictions based on classical core accretion. Pebble drift, coupled with volatile evaporation, has been proposed as a possible remedy to this since the level of heavy element enrichment a planet can accrete, as well as its atmospheric composition, is strongly dependent on where in the disc it is forming. We used a planet formation model that simulates the evolution of the protoplanetary disc, accounting for pebble growth, drift and evaporation, and the formation of planets from pebble and gas accretion. We simulated the growth and migration of planetary embryos in ten different protoplanetary discs whose chemical compositions are matched to the host stars of the planets that we aim to reproduce; this provided a more realistic model of their growth than previous studies. The heavy element content of giant exoplanets was used to infer their formation location and thus to estimate their atmospheric abundances. We focused on giants more massive than Saturn, as we expect that their heavy element content is dominated by their envelope rather than their core. The heavy element content of nine out of the ten simulated planets is successfully matched to their observed values. Our simulations predict formation in the inner disc regions, where the majority of the volatiles have already evaporated and can thus be accreted onto the planet via the gas. As the majority of the planetary heavy element content originates from water vapour accretion, our simulations predict a high atmospheric O/H ratio in combination with a low atmospheric C/O ratio, which is in general agreement with observations. For certain planets, namely WASP-84b, these properties may be observable in the near future, offering a method of testing the constraints placed on the planet’s formation
Resolving the terrestrial planet-forming region of HD 172555 with ALMA
No full textContext. Giant impacts between planetary embryos are a natural step in the terrestrial planet formation process and are expected to create disks of warm debris in the terrestrial regions of their stars. Understanding the gas and dust debris produced in giant impacts is vital for comprehending and constraining models of planetary collisions.
Aims. We reveal the distribution of millimeter (mm) grains in the giant impact debris disk of HD 172555 for the first time, using new ALMA 0.87 mm observations at ∼80 mas (2.3 au) resolution.
Methods. We modeled the interferometric visibilities to obtain basic spatial properties of the disk and compared these data to the disk’s dust and gas distributions at other wavelengths.
Results. We detected the star and dust emission from an inclined disk out to ∼9 au and down to 2.3 au (on-sky) from the central star, with no significant asymmetry in the dust distribution. The radiative transfer modeling of the visibilities indicates the disk surface density distribution of mm grains most likely peaks around ∼5 au, while the width inferred remains model-dependent at the S/N of the data. We highlighted an outward radial offset of the small grains traced by scattered light observations compared to the mm grains, which could be explained by the combined effect of gas drag and radiation pressure in the presence of large enough gas densities. Furthermore, our SED modeling implies a size distribution slope for the mm grains consistent with the expectation of collisional evolution and flatter than inferred for the micron-sized grains, implying a break in the grain size distribution and confirming an overabundance of small grains
Interacting supernovae and where to find them
No full textContext. The early interaction of supernova blast waves with circumstellar material has the potential to accelerate particles to petaelectronvolt energies, although this has not yet been detected. Current models for this interaction assume that the blast wave expands into a smooth freely expanding stellar wind, although multiwavelength observations of many supernovae do not support this assumption.
Aims. We extend previous work by considering blast waves expanding into complex density profiles consisting of smooth winds with dense circumstellar shells at various distances from the progenitor star. We aim to predict the gamma-ray and multiwavelength signatures of circumstellar interaction.
Methods. We used the code PION to model the circumstellar medium around luminous blue variables including a brief episode of enhanced mass-loss and to simulate the formation of photoionization-confined shells around red supergiants. Consequently, we used the time-dependent acceleration code RATPaC to study the acceleration of cosmic rays in supernovae expanding into these media and to evaluate the emitted radiation (both thermal and nonthermal) across the whole electromagnetic spectrum.
Results. We find that the interaction with the circumstellar shells can significantly boost the gamma-ray emission of a remnant, with the emission peaking weeks to years after the explosion when γγabsorption has reduced to negligible levels. The peak luminosity for Type IIP and Type IIn remnants can exceed the luminosity expected for smooth winds by several orders of magnitude. For Type IIP explosions, the light-curve peak is only reached years after the explosion, when the blast wave reaches the circumstellar shell. We evaluated the multiwavelength signatures expected from the interaction of the blast wave with a dense circumstellar shell from radio to optical and thermal X-rays.
Conclusions. High-cadence optical surveys and continuous monitoring of nearby supernovae in radio and millimeter wavelengths are the best-suited strategies for identifying targets. They should be followed-up by gamma-ray observatories. We predict that gamma-rays from interaction with dense circumstellar shells may be detectable out to a few megaparsec for late interaction and out to tens of megaparsec for an early interaction
The Tarantula massive binary monitoring
No full textMassive O-type stars (M ≳ 15 M⊙) with an X-ray-quiet black hole (BH) companion represent a crucial stage in the massive binary evolution leading to binary BH mergers. The population of such binaries remains elusive, with ≲5 candidate or confirmed systems. The Tarantula nebula harbors thousands of massive stars, 2–3% of which are expected to have BH companions. It is therefore an ideal place to hunt for such systems. We analyzed 30 epochs of VLT/FLAMES IFU high-resolution observations of the Hδ region and archival FLAMES spectroscopy of VFTS 812, a 17-day single-lined spectroscopic binary with an O4 V primary and a minimum secondary mass of 5.1 M⊙. Following careful removal of the nebular contamination, spectral disentangling on the new data did not reveal any signature of the hidden companion. We derive kK, log L = 5.7 ± 0.1, and km s−1 for the O4 V component, yielding a (single-star) evolutionary mass of and an age in the range 0–1.6 Myr. Using injection tests for various luminous artificial companions in our data, we exhaustively ruled out the presence of any luminous signature from a main sequence star more massive than 6 M⊙. We discuss the possible nature of the companion, suggesting that a rejuvenated O star + BH companion is the most suitable scenario to consistently explain the location, (rejuvenated) young age, eccentricity, and lack of companion signature. While this establishes VFTS 812 as a strong candidate O + BH system, follow-up observations are deemed necessary for a robust confirmation and to search for accretion signatures on the O4 V star
The BINGO project. X. Cosmological parameter constraints from HI intensity mapping lognormal simulations
No full textBuilding on the transformative success of optical redshift surveys, the emerging technique of neutral hydrogen (HI) intensity mapping (IM) offers a novel probe of large-scale structure (LSS) growth and the late-time accelerated expansion of the Universe.
We present cosmological forecasts for the Baryon acoustic oscillations from Integrated Neutral Gas Observations (BINGO) project, a pioneering HI IM experiment, quantifying its potential to constrain the Planck-calibrated lambda-cold dark matter (ΛCDM) cosmology and extensions to the w_0w_aCDM dark energy model.
For BINGO's phase 1 configuration, we simulated the HI IM signal using a lognormal model and incorporated three dominant systematics: foreground residuals, thermal noise, and beam resolution effects. Using Bayesian inference, we derived joint constraints on six cosmological parameters (Ω_b h^2, Ω_c h^2, 100þeta_s, n_s, łn 10^ 10 A_s, and τ_r) alongside 60 HI parameters (b_ ̊m HI ^i, Ω_ ̊m HI ^i b_ ̊m HI ^i) across 30 frequency channels.
Our results demonstrate that combining BINGO with the Planck 2018 Cosmic Microwave Background (CMB) dataset tightens the confidence regions of cosmological parameters to ∼40% the size of those from Planck alone, significantly improving the precision of parameter estimation. Furthermore, BINGO constrains the redshift evolution of HI density and delivers competitive measurements of the dark energy equation of state parameters (w_0, w_a).
These results demonstrate BINGO’s potential to extract significant cosmological information from the HI distribution and provide constraints competitive with current and future cosmological surveys