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Deep neural network (DNN)-based joint source and channel coding is proposed for end-to-end secure image transmission against multiple eavesdroppers. Both scenarios of colluding and non-colluding eavesdroppers are considered. Instead of idealistic assumptions of perfectly known and i.i.d. source and channel distributions, the proposed scheme assumes unknown source and channel statistics. The goal is to transmit images with minimum distortion, while simultaneously preventing eavesdroppers from inferring private attributes of images. Simultaneously generalizing the ideas of privacy funnel and wiretap coding, a multi-objective optimization framework is expressed that characterizes the trade-off between image reconstruction quality and information leakage to eavesdroppers, taking into account the structural similarity index (SSIM) for improving the perceptual quality of image reconstruction. Extensive experiments over CIFAR-10 and CelebFaces Attributes (CelebA) datasets, together with ablation studies are provided to highlight the performance gain in terms of SSIM, adversarial accuracy, and cross-entropy metric compared with benchmarks. Experiments show that the proposed scheme restrains the adversarially-trained eavesdroppers from intercepting privatized data for both cases of eavesdropping a common secret, as well as the case in which eavesdroppers are interested in different secrets. Furthermore, useful insights on the privacy-utility trade-off are also provided.

MPI-Rockstar is a massively parallel halo finder based on the Rockstar phase-space temporal halo finder code, which is one of the most extensively used halo finding codes. Compared to the original code, parallelized by a primitive socket communication library, we parallelized it in a hybrid way using MPI and OpenMP, which is suitable for analysis on the hybrid shared and distributed memory environments of modern supercomputers. This implementation can easily handle the analysis of more than a trillion particles on more than 100,000 parallel processes, enabling the production of a huge dataset for the next generation of cosmological surveys. As new functions to the original Rockstar code, MPI-Rockstar supports HDF5 as an output format and can output additional halo properties such as the inertia tensor., Comment: 3 pages, submitted to Journal of Open Source Software (JOSS), GitHub repository: https://github.com/Tomoaki-Ishiyama/mpi-rockstar/

Wide-field cosmological surveys provide hundreds of thousands of spectroscopically confirmed galaxy groups and clusters, valuable for tracing baryonic matter distribution. However, controlling systematics in identifying host dark matter halos and estimating their properties is crucial. We evaluate three group detection methods on a simulated dataset replicating the GAMA selection to understand systematics and selection effects. This is key for interpreting data from SDSS, GAMA, DESI, WAVES, and leveraging optical catalogues in the (X-ray) eROSITA era to quantify baryonic mass in galaxy groups. Using a lightcone from the Magneticum hydrodynamical simulation, we simulate a spectroscopic galaxy survey in the local Universe (down to $z<0.2$ and stellar mass completeness $M_{\star}\geq10^{9.8} M_{\odot}$). We assess completeness and contamination of reconstructed halo catalogues, evaluate membership accuracy, and analyse the halo mass recovery rate of group finders. All three group finders achieve high completeness ($>80\%$) at group and cluster scales, confirming optical selection's suitability for dense regions. Contamination at low masses ($M_{200}<10^{13} M_{\odot}$) arises from interlopers and fragmentation. Membership is at least 70\% accurate above the group mass scale, but inaccuracies bias halo mass estimates using galaxy velocity dispersion. Alternative proxies, like total stellar luminosity or mass, yield more accurate halo masses. The cumulative luminosity function of galaxy members matches predictions, showing the group finders' accuracy in identifying galaxy populations. These results confirm the reliability and completeness of spectroscopic catalogues produced by state-of-the-art group finders. This supports studies requiring large spectroscopic samples of galaxy groups and clusters, as well as investigations into galaxy evolution across diverse environments., Comment: submitted to A&A, 17 pages, 9 figures. Abstract reduced for ArXiv submission

Existing 3D facial emotion modeling have been constrained by limited emotion classes and insufficient datasets. This paper introduces "Emo3D", an extensive "Text-Image-Expression dataset" spanning a wide spectrum of human emotions, each paired with images and 3D blendshapes. Leveraging Large Language Models (LLMs), we generate a diverse array of textual descriptions, facilitating the capture of a broad spectrum of emotional expressions. Using this unique dataset, we conduct a comprehensive evaluation of language-based models' fine-tuning and vision-language models like Contranstive Language Image Pretraining (CLIP) for 3D facial expression synthesis. We also introduce a new evaluation metric for this task to more directly measure the conveyed emotion. Our new evaluation metric, Emo3D, demonstrates its superiority over Mean Squared Error (MSE) metrics in assessing visual-text alignment and semantic richness in 3D facial expressions associated with human emotions. "Emo3D" has great applications in animation design, virtual reality, and emotional human-computer interaction., Comment: 11 pages, 10 figures

We infer supermassive black hole (SMBH) accretion rates and Eddington ratios as a function of SMBH/host galaxy mass and redshift with the empirical TRINITY model of dark matter halo--galaxy--SMBH connection. The galaxy--SMBH mass and growth rate connection from TRINITY is constrained by galaxy observables from $06$: at these redshifts, dark matter halos experience $\sim$Eddington specific growth rates, driving $\sim$Eddington specific growth rates in both galaxies and SMBHs., Comment: 14 pages, 19 figures, submitted to MNRAS

Public transportation systems play a crucial role in daily commutes, business operations, and leisure activities, emphasizing the need for effective management to meet public demands. One approach to achieve this goal is by predicting demand at the station level. Bike-sharing systems, as a form of transit service, contribute to the reduction of air and noise pollution, as well as traffic congestion. This study focuses on predicting travel demand within a bike-sharing system. A novel hybrid deep learning model called the gate graph convolutional neural network is introduced. This model enables prediction of the travel demand at station level. By integrating trajectory data, weather data, access data, and leveraging gate graph convolution networks, the accuracy of travel demand forecasting is significantly improved. Chicago City bike-sharing system is chosen as the case study. In this investigation, the proposed model is compared to the base models used in previous literature to evaluate their performance, demonstrating that the main model exhibits better performance than the base models. By utilizing this framework, transportation planners can make informed decisions on resource allocation and rebalancing management.

Aspera is a NASA Astrophysics Pioneers SmallSat mission designed to study diffuse OVI emission from the warm-hot phase gas in the halos of nearby galaxies. Its payload consists of two identical Rowland Circle-type long-slit spectrographs, sharing a single MicroChannel plate detector. Each spectrograph channel consists of an off-axis parabola primary mirror and a toroidal diffraction grating optimized for the 1013-1057 Angstroms bandpass. Despite the simple configuration, the optical alignment/integration process for Aspera is challenging due to tight optical alignment tolerances, driven by the compact form factor, and the contamination sensitivity of the Far-Ultraviolet optics and detectors. In this paper, we discuss implementing a novel multi-phase approach to meet these requirements using state-of-the-art optical metrology tools. For coarsely positioning the optics we use a blue-laser 3D scanner while the fine alignment is done with a Zygo interferometer and a custom computer-generated hologram. The detector focus requires iterative in-vacuum alignment using a Vacuum UV collimator. The alignment is done in a controlled cleanroom facility at the University of Arizona., Comment: Manuscript submitted for Proceedings of Astronomical Telescopes + Instrumentation 2024, Paper no. 13093-9

For the joint analysis of second-order weak lensing and galaxy clustering statistics, so-called $3{\times}2$ analyses, the selection and characterization of optimal galaxy samples is a major area of research. One promising choice is to use the same galaxy sample as lenses and sources, which reduces the systematics parameter space that describes uncertainties related to galaxy samples. Such a "lens-equal-source" analysis significantly improves self-calibration of photo-z systematics leading to improved cosmological constraints. With the aim to enable a lens-equal-source analysis on small scales we investigate the halo-galaxy connection of DES-Y3 source galaxies. We develop a technique to construct mock source galaxy populations by matching COSMOS/UltraVISTA photometry onto UniverseMachine galaxies. These mocks predict a source halo occupation distribution (HOD) that exhibits significant redshift evolution, non-trivial central incompleteness and galaxy assembly bias. We produce multiple realizations of mock source galaxies drawn from the UniverseMachine posterior with added uncertainties in measured DES photometry and galaxy shapes. We fit a modified HOD formalism to these realizations to produce priors on the galaxy-halo connection for cosmological analyses. We additionally train an emulator that predicts this HOD to $\sim2\%$ accuracy from redshift $z = 0.1 - 1.3$ that models the dependence of this HOD on 1) observational uncertainties in galaxy size and photometry, and 2) uncertainties in the UniverseMachine predictions., Comment: 15 pages, 7 figures, 1 table. Submitted to The Astrophysical Journal

Environment plays a critical role in shaping the assembly of low-mass galaxies. Here, we use the UniverseMachine (UM) galaxy-halo connection framework and the Data Release 3 of the Satellites Around Galactic Analogs (SAGA) Survey to place dwarf galaxy star formation and quenching into a cosmological context. UM is a data-driven forward model that flexibly parameterizes galaxy star formation rates (SFR) using only halo mass and assembly history. We add a new quenching model to UM, tailored for galaxies with stellar masses $\lesssim 10^9$ solar masses, and constrain the model down to a stellar mass $\gtrsim 10^7$ solar masses using new SAGA observations of 101 satellite systems around Milky Way (MW)-mass hosts and a sample of isolated field galaxies in a similar mass range from the Sloan Digital Sky Survey (SDSS). The new best-fit model, 'UM-SAGA,' reproduces the satellite stellar mass functions, average SFRs, and quenched fractions in SAGA satellites while keeping isolated dwarfs mostly star forming. The enhanced quenching in satellites relative to isolated field galaxies leads the model to maximally rely on halo assembly to explain the observed environmental quenching. Extrapolating the model down to a stellar mass $\sim 10^{6.5}$ solar masses yields a quenched fraction of $\gtrsim$ 30% for isolated field galaxies and $\gtrsim$ 80% for satellites of MW-mass hosts at this stellar mass. This specific prediction can soon be tested by spectroscopic surveys to reveal the relative importance of internal feedback, cessation of mass and gas accretion, satellite-specific gas processes, and reionization for the evolution of faint low-mass galaxies., Comment: 33 pages, 14 figures, 2 tables. This paper is part of the SAGA Survey Data Release 3. Survey website: https://sagasurvey.org

We measure the clustering of low-redshift SDSS galaxies as a function of stellar mass ($10.0<\log(M_*/M_\odot)<11.5$) and specific star formation rate (sSFR) and compare the results to models of the galaxy--halo connection. We find that the auto-correlation functions of central galaxies exhibit little dependence on sSFR, with the well-known stronger clustering of quiescent galaxies mainly attributable to satellites. Because halo assembly history is known to affect distinct halo clustering, this result implies that there is little net correlation between halo assembly history and central galaxy sSFR. However, cross-correlations with satellites are stronger for quiescent centrals than star-forming centrals, consistent with quiescent centrals having more satellites in their haloes at fixed $M_*$, as found in SDSS group catalogues. We model the galaxy--halo connection in an $N$-body simulation by assigning sSFRs to central galaxies in three different ways. Two of the models depend on halo assembly history (being based on halo accretion rate or concentration), while the third is independent of halo assembly history (being based on peak halo circular velocity, $V_\text{peak}$, a proxy for halo mass). All three models replicate the observed auto-correlations of central galaxies, while only the $V_\text{peak}$ model reproduces the observed cross-correlations with satellites. This further suggests that the effects of halo assembly history may not be easily seen in auto-correlations of centrals and implies that a more complete understanding of central galaxy clustering may require more than auto-correlations of centrals alone. Additionally, the good agreement with the $V_\text{peak}$ model supports the idea that quiescent galaxies reside in more massive haloes than star-forming galaxies at fixed $M_*$., Comment: MNRAS accepted, 26 pages

In this investigation, we leverage the combination of Dark Energy Spectroscopic Instrument Legacy imaging Surveys Data Release 9 (DESI LS DR9), Survey Validation 3 (SV3), and Year 1 (Y1) data sets to estimate the conditional luminosity and stellar mass functions (CLFs & CSMFs) of galaxies across various halo mass bins and redshift ranges. To support our analysis, we utilize a realistic DESI Mock Galaxy Redshift Survey (MGRS) generated from a high-resolution Jiutian simulation. An extended halo-based group finder is applied to both MGRS catalogs and DESI observation. By comparing the r and z-band luminosity functions (LFs) and stellar mass functions (SMFs) derived using both photometric and spectroscopic data, we quantified the impact of photometric redshift (photo-z) errors on the galaxy LFs and SMFs, especially in the low redshift bin at low luminosity/mass end. By conducting prior evaluations of the group finder using MGRS, we successfully obtain a set of CLF and CSMF measurements from observational data. We find that at low redshift the faint end slopes of CLFs and CSMFs below $10^{9}h^{-2}L_{\odot}$ (or $h^{-2}M_{\odot}$) evince a compelling concordance with the subhalo mass functions. After correcting the cosmic variance effect of our local Universe following arXiv:1809.00523, the faint end slopes of the LFs/SMFs turn out to be also in good agreement with the slope of the halo mass function., Comment: 28 pages, 13 figures, Accepted for publication in ApJ

The wavelength-coverage and sensitivity of JWST now enables us to probe the rest-frame UV - optical spectral energy distributions (SEDs) of galaxies at high-redshift ($z>4$). From these SEDs it is, in principle, through SED fitting possible to infer key physical properties, including stellar masses, star formation rates, and dust attenuation. These in turn can be compared with the predictions of galaxy formation simulations allowing us to validate and refine the incorporated physics. However, the inference of physical properties, particularly from photometry alone, can lead to large uncertainties and potential biases. Instead, it is now possible, and common, for simulations to be \emph{forward-modelled} to yield synthetic observations that can be compared directly to real observations. In this work, we measure the JWST broadband fluxes and colours of a robust sample of $58$ the distributions differ somewhat, though our observed sample size is small and thus susceptible to statistical fluctuations. Likewise, the predicted and observed colour evolution show broad agreement, at least at $58$, though, again, the sample size is small here., Comment: 11 pages, 10 figures, submitted to MNRAS

We present a sample of 88 candidate z~8.5-14.5 galaxies selected from the completed NIRCam imaging from the Cosmic Evolution Early Release Science (CEERS) survey. These data cover ~90 arcmin^2 (10 NIRCam pointings) in six broad-band and one medium-band imaging filter. With this sample we confirm at higher confidence early JWST conclusions that bright galaxies in this epoch are more abundant than predicted by most theoretical models. We construct the rest-frame ultraviolet luminosity functions at z~9, 11 and 14, and show that the space density of bright (M_UV=-20) galaxies changes only modestly from z~14 to z~9, compared to a steeper increase from z~8 to z~4. While our candidates are photometrically selected, spectroscopic followup has now confirmed 13 of them, with only one significant interloper, implying that the fidelity of this sample is high. Successfully explaining the evidence for a flatter evolution in the number densities of UV-bright z>10 galaxies may thus require changes to the dominant physical processes regulating star formation. While our results indicate that significant variations of dust attenuation with redshift are unlikely to be the dominant factor at these high redshifts, they are consistent with predictions from models which naturally have enhanced star-formation efficiency and/or stochasticity. An evolving stellar initial mass function could also bring model predictions into better agreement with our results. Deep spectroscopic followup of a large sample of early galaxies can distinguish between these competing scenarios., Comment: Submitted to ApJL. Main paper is 33 pages, 13 figures, 5 tables. Two appendices with additional figures and tables

Dark matter halo demographics and assembly histories are a manifestation of cosmological structure formation and have profound implications for the formation and evolution of galaxies. In particular, merger trees provide fundamental input for several modelling techniques, such as semi-analytic models (SAMs), sub-halo abundance matching (SHAM), and decorated halo occupation distribution models (HODs). Motivated by the new ultra-high-redshift (z > 10) frontier enabled by JWST, we present a new suite of Gadget at Ultrahigh Redshift with Extra-Fine Timesteps (GUREFT) dark matter-only cosmological simulations that are carefully designed to capture halo merger histories and structural properties in the ultra-z universe. The simulation suite consists of four 1024^3-particle simulations with box sizes of 5, 15, 35, and 90 Mpc h-1, each with 170 snapshots stored between 40 > z > 6. With the unprecedented number of available snapshots and strategically chosen dynamic range covered by these boxes, gureft uncovers the emerging dark matter halo populations and their assembly histories in the earliest epochs of cosmic history. In this work, we present the halo mass functions between z ~ 20 to 6 down to log(Mvir/Msun) ~ 5, and show that at high redshift, these robust halo mass functions can differ substantially from commonly used analytic approximations or older fitting functions in the literature. We also present key physical properties of the ultra-z halo population, such as concentration and spin, as well as their mass growth and merger rates, and again provide updated fitting functions., Comment: 20 pages, 18 figures, accepted for publication in MNRAS

We present predictions for the high-redshift halo-galaxy-supermassive black hole (SMBH) connection from the TRINITY model. Constrained by a comprehensive compilation of galaxy ($0\leq z \leq 10$) and SMBH datasets ($0\leq z \leq 6.5$), TRINITY finds: 1) The number of SMBHs with $M_\bullet > 10^9 M_\odot$ in the observable Universe increases by six orders of magnitude from $z\sim10$ to $z\sim2$, and by another factor of $\sim 3$ from $z\sim2$ to $z=0$; 2) The $M_\bullet > 10^9/10^{10} M_\odot$ SMBHs at $z\sim 6$ live in haloes with $\sim (2-3)/(3-5) \times 10^{12} M_\odot$; 3) the new JWST AGNs at $7\lesssim z \lesssim 11$ are broadly consistent with the median SMBH mass-galaxy mass relation for AGNs from TRINITY; 4) Seeds from runaway mergers in nuclear star clusters are viable progenitors for the SMBHs in GN-z11 ($z=10.6$) and CEERS_1019 ($z=8.7$); 5) $z=6-10$ quasar luminosity functions from wide area surveys by, e.g., Roman and Euclid, will reduce uncertainties in the $z=6-10$ SMBH mass-galaxy mass relation by up to $\sim 0.5$ dex., Comment: 15 pages, 12 figures, submitted to MNRAS. Questions and comments are welcome!

Despite the Milky Way's proximity to us, our knowledge of its dark matter halo is fairly limited, and there is still considerable uncertainty in its halo mass. Many past techniques have been limited by assumptions such as the Galaxy being in dynamical equilibrium as well as nearby galaxies being true satellites of the Galaxy, and/or the need to find large samples of Milky Way analogs in simulations.Here, we propose a new technique based on neural networks that obtains high precision ($<0.14$ dex mass uncertainty) without assuming halo dynamical equilibrium or that neighboring galaxies are all satellites, and which can use information from a wide variety of simulated halos (even those dissimilar to the Milky Way) to improve its performance. This method uses only observable information including satellite orbits, distances to nearby larger halos, and the maximum circular velocity of the largest satellite galaxy. In this paper, we demonstrate a proof-of-concept method on simulated dark matter halos; in future papers in this series, we will apply neural networks to estimate the masses of the Milky Way's and M31's dark matter halos, and we will train variations of these networks to estimate other halo properties including concentration, assembly history, and spin axis.

Given a rectangle $R$ with area $A$ and a set of areas $L=\{A_1,...,A_n\}$ with $\sum_{i=1}^n A_i = A$, we consider the problem of partitioning $R$ into $n$ sub-regions $R_1,...,R_n$ with areas $A_1,...,A_n$ in a way that the total perimeter of all sub-regions is minimized. The goal is to create square-like sub-regions, which are often more desired. We propose an efficient $1.203$--approximation algorithm for this problem based on a divide and conquer scheme that runs in $\mathcal{O}(n^2)$ time. For the special case when the aspect ratios of all rectangles are bounded from above by 3, the approximation factor is $2/\sqrt{3} \leq 1.1548$. We also present a modified version of out algorithm as a heuristic that achieves better average and best run times.

Treemaps have been widely applied to the visualization of hierarchical data. A treemap takes a weighted tree and visualizes its leaves in a nested planar geometric shape, with sub-regions partitioned such that each sub-region has an area proportional to the weight of its associated leaf nodes. Efficiently generating visually appealing treemaps that also satisfy other quality criteria is an interesting problem that has been tackled from many directions. We present an optimization model and five new algorithms for this problem, including two divide and conquer approaches and three spiral treemap algorithms. Our optimization model is able to generate superior treemaps that could serve as a benchmark for comparing the quality of more computationally efficient algorithms. Our divide and conquer and spiral algorithms either improve the performance of their existing counterparts with respect to aspect ratio and stability or perform competitively. Our spiral algorithms also expand their applicability to a wider range of input scenarios. Four of these algorithms are computationally efficient as well with quasilinear running times and the last algorithm achieves a cubic running time. A full version of this paper with all appendices, data, and source codes is available at \anonymizeOSF{\OSFSupplementText}.

We consider a combined system of regular delivery trucks and crowdsourced drones, available via a sharing economy platform, to provide a technology-assisted crowd-based last-mile delivery experience. We develop analytical models and methods for a system in which package delivery is performed by a big truck carrying many packages to a neighborhood or a town in a metropolitan area and then the packages are assigned to crowdsourced drone operators to deliver them to their final destinations. We develop several optimization models for various cases of the problem and use a combination of heuristic algorithms to solve this NP-hard problem. Finally, we present computational results for the models and algorithms, and conduct an exhaustive sensitivity analysis to check the influence of different parameters and assumptions on the final results. We also provide extensive managerial insights on the benefits of our proposed model if implemented in practice.

In this paper, a generalization of deep learning-aided joint source channel coding (Deep-JSCC) approach to secure communications is studied. We propose an end-to-end (E2E) learning-based approach for secure communication against multiple eavesdroppers over complex-valued fading channels. Both scenarios of colluding and non-colluding eavesdroppers are studied. For the colluding strategy, eavesdroppers share their logits to collaboratively infer private attributes based on ensemble learning method, while for the non-colluding setup they act alone. The goal is to prevent eavesdroppers from inferring private (sensitive) information about the transmitted images, while delivering the images to a legitimate receiver with minimum distortion. By generalizing the ideas of privacy funnel and wiretap channel coding, the trade-off between the image recovery at the legitimate node and the information leakage to the eavesdroppers is characterized. To solve this secrecy funnel framework, we implement deep neural networks (DNNs) to realize a data-driven secure communication scheme, without relying on a specific data distribution. Simulations over CIFAR-10 dataset verifies the secrecy-utility trade-off. Adversarial accuracy of eavesdroppers are also studied over Rayleigh fading, Nakagami-m, and AWGN channels to verify the generalization of the proposed scheme. Our experiments show that employing the proposed secure neural encoding can decrease the adversarial accuracy by 28%.

Supply chain disruption can occur for a variety of reasons, including natural disasters or market dynamics for which resilient strategies should be designed. If the disruption is profound and with dire consequences for the economy, it calls for the regulator's intervention to minimize the impact for the betterment of the society. This paper considers a shipping company with limited capacity which will ship a group of products with heterogeneous transportation and production costs and prices, and investigates the minimum quota regulation on transportation amounts stipulated by the government. An interesting example can happen in North American rail transportation market, where the rail capacity is used for a variety of products and commodities such as oil and grains. Similarly, in Europe supply chain of grains produced in Ukraine is disrupted by the Ukraine war and the blockade of sea transportation routes, which puts pressure on rail transportation capacity of Ukraine and its neighboring countries to the west that needs to be shared for shipping a variety of products including grains, military, and humanitarian supplies. Such situations require a proper execution of government intervention for effective management of the limited transportation capacity to avoid the rippling effects throughout the economy. We propose mathematical models and solutions for the market players and the government in a Canadian case study. Subsequently, the conditions that justify government intervention are identified, and an algorithm to obtain the optimum minimum quotas is presented.

The stellar mass - halo mass relation provides a strong basis for connecting galaxies to their host dark matter halos in both simulations and observations. Other observable information, such as the density of the local environment, can place further constraints on a given halo's properties. In this paper, we test how the peak masses of dark matter halos and subhalos correlate with observationally-accessible environment measures, using a neural network to extract as much information from the environment as possible. For high mass halos (peak mass $>10^{12.5} M_{\odot}$), the information on halo mass contained in stellar mass - selected galaxy samples is confined to the $\sim$ 1 Mpc region surrounding the halo center. Below this mass threshold, nearly the entirety of the information on halo mass is contained in the galaxy's own stellar mass instead of the neighboring galaxy distribution. The overall root-mean-squared error of the best-performing network was 0.20 dex. When applied to only the central halos within the test data, the same network had an error of 0.17 dex. Our findings suggest that, for the purposes of halo mass inference, both distances to the $k$th nearest neighbor and counts in cells of neighbors in a fixed aperture are similarly effective measurements of the local environment., Comment: Accepted to the Open Journal of Astrophysics; 17 pages, 20 figures; revised version

Accurately modeling the cold gas content in the universe is challenging for current theoretical models. We propose a new empirical model NeutralUniverseMachine for the evolution of HI and H$_2$ gas along with dark matter halos based on the UniverseMachine catalog. It is able to accurately describe the observed HI and H$_2$ mass functions, molecular-to-atomic ratio, HI-halo mass relation, HI/H$_2$-stellar mass relations at $z\sim0$, as well as the evolution of cosmic gas densities $\rho_{\rm HI}$ and $\rho_{\rm H_2}$ in $0

We develop two simple and efficient approximation algorithms for the continuous $k$-medians problems, where we seek to find the optimal location of $k$ facilities among a continuum of client points in a convex polygon $C$ with $n$ vertices in a way that the total (average) Euclidean distance between clients and their nearest facility is minimized. Both algorithms run in $\mathcal{O}(n + k + k \log n)$ time. Our algorithms produce solutions within a factor of 2.002 of optimality. In addition, our simulation results applied to the convex hulls of the State of Massachusetts and the Town of Brookline, MA show that our algorithms generally perform within a range of 5\% to 22\% of optimality in practice.

We present the redshift evolution of quasar luminosity functions decomposed by halo mass, galaxy mass, supermassive black hole (SMBH) mass, and Eddington ratio, as well as SMBH kinetic/radiative energy output ratios from TRINITY, a flexible empirical model that self-consistently infers the halo--galaxy--SMBH connection that match observational data. Key findings include: 1) The normalization of QLF increases by ~3-4 dex from z~10 to z~4, due to the fast mass build-up of different SMBH populations; 2) From z~4 to z~1, less massive galaxies and SMBHs make up bigger and bigger fractions of QLFs, due to the AGN downsizing effect; 3) At z~0, massive haloes/galaxies/SMBHs are responsible for most bright quasars due to low Eddington ratios among all SMBHs; 4) The bright ends of quasar luminosity functions (QLFs) are dominated by SMBHs that are at least 0.3 dex over-massive relative to the median SMBH mass-galaxy mass relation; 5) QLFs at z~6-7 are dominated by SMBHs accreting at Eddington ratios 0.1 < $\eta_\mathrm{rad}$ < 1, but super-Eddington AGNs contribute more significantly to QLFs towards z~9-10., Comment: 18 pages, 14 figures. Accepted by MNRAS. Comments welcome!

We analyze the Near Infrared ($\sim0.8-1\mu$m) rest-frame morphologies of galaxies with $\log M_*/M_\odot>9$ in the redshift range $010.5$) at $z\sim5$, and bulge-dominated galaxies also exist at these early epochs, confirming a rich and evolved morphological diversity of galaxies $\sim1$ Gyr after the Big Bang. Finally, we find that the morphology-quenching relation is already in place for massive galaxies at $z>3$, with massive quiescent galaxies ($\log M_*/M_\odot>10.5$) being predominantly bulge-dominated., Comment: Submitted to A&A, comments welcome

Dark matter subhaloes are key for the predictions of simulations of structure formation, but their existence frequently ends prematurely due to two technical issues, namely numerical disruption in N-body simulations and halo finders failing to identify them. Here we focus on the second issue, using the phase-space friends-of-friends halo finder ROCKSTAR as a benchmark (though we expect our results to translate to comparable codes). We confirm that the most prominent cause for losing track of subhaloes is tidal distortion rather than a low number of particles. As a solution, we present a flexible post-processing algorithm that tracks all subhalo particles over time, computes subhalo positions and masses based on those particles, and progressively removes stripped matter. If a subhalo is lost by the halo finder, this algorithm keeps tracking its so-called ghost until it has almost no particles left or has truly merged with its host. We apply this technique to a large suite of N-body simulations and restore lost subhaloes to the halo catalogues, which has a dramatic effect on key summary statistics of large-scale structure. Specifically, the subhalo mass function increases by about 50% and the halo correlation function increases by a factor of two at small scales. While these quantitative results are somewhat specific to our algorithm, they demonstrate that particle tracking is a promising way to reliably follow haloes and reduce the need for orphan models. Our algorithm and augmented halo catalogues are publicly available., Comment: 16 pages, 10 figures. Comments welcome

In their recent study, Labb\'e et al. used multi-band infrared images captured by the James Webb Space Telescope (JWST) to discover a population of red massive galaxies that formed approximately 600 million years after the Big Bang. The authors reported an extraordinarily large density of these galaxies, with stellar masses exceeding $10^{10}$ solar masses, which, if confirmed, challenges the standard cosmological model as suggested by recent studies. However, this conclusion is disputed. We contend that during the early epochs of the universe the stellar mass-to-light ratio could not have reached the values reported by Labb\'e et al. A model of galaxy formation based on standard cosmology provides support for this hypothesis, predicting the formation of massive galaxies with higher ultraviolet (UV) luminosity, which produce several hundred solar masses of stars per year and containing significant dust. These forecasts are consistent with the abundance of JWST/HST galaxies selected photometrically in the rest-frame UV wavelengths and with the properties of the recent spectroscopically-confirmed JWST/HST galaxies formed during that era. Discrepancies with Labb\'e et al. may arise from overestimation of the stellar masses, systematic uncertainties, absence of JWST/MIRI data, heavy dust extinction affecting UV luminosities, or misidentification of faint red AGN galaxies at closer redshifts. The current JWST/HST results, combined with a realistic galaxy formation model, provide strong confirmation of the standard cosmology., Comment: Submitted to Nature, matters arising

Mid-infrared observations are powerful in identifying heavily obscured Active Galactic Nuclei (AGN) which have weak emission in other wavelengths. Data from the Mid-Infrared Instrument (MIRI) onboard JWST provides an excellent opportunity to perform such studies. We take advantage of the MIRI imaging data from the Cosmic Evolution Early Release Science Survey (CEERS) to investigate the AGN population in the distant universe. We estimate the source properties of MIRI-selected objects by utilizing spectral energy distribution (SED) modelling, and classify them into star-forming galaxies (SF), SF-AGN mixed objects, and AGN. The source numbers of these types are 418, 111, and 31, respectively, from 4 MIRI pointings covering $\sim 9$ arcmin$^2$. The sample spans a redshift range of $\approx 0$--5. We derive the median SEDs for all three source types, respectively, and publicly release them. The median MIRI SED of AGN is similar to the typical SEDs of hot dust-obscured galaxies and Seyfert 2s, for which the mid-IR SEDs are dominantly from AGN-heated hot dust. Based on our SED-fit results, we estimate the black-hole accretion density (BHAD; i.e., total BH growth rate per comoving volume) as a function of redshift. At $z<3$, the resulting BHAD agrees with the X-ray measurements in general. At $z>3$, we identify a total of 27 AGN and SF-AGN mixed objects, leading to that our high-$z$ BHAD is substantially higher than the X-ray results ($\sim 0.5$ dex at $z \approx 3$--5). This difference indicates MIRI can identify a large population of heavily obscured AGN missed by X-ray surveys at high redshifts., Comment: ApJL in press, as part of the CEERS Focus Issue. 13 pages and 7 figures (median SEDs in Fig. 5 are available upon request)

We report the discovery of an accreting supermassive black hole at z=8.679, in CEERS_1019, a galaxy previously discovered via a Ly$\alpha$-break by Hubble and with a Ly$\alpha$ redshift from Keck. As part of the Cosmic Evolution Early Release Science (CEERS) survey, we observed this source with JWST/NIRSpec spectroscopy, MIRI and NIRCam imaging, and NIRCam/WFSS slitless spectroscopy. The NIRSpec spectra uncover many emission lines, and the strong [O III] emission line confirms the ground-based Ly$\alpha$ redshift. We detect a significant broad (FWHM~1200 km/s) component in the H$\beta$ emission line, which we conclude originates in the broad-line region of an active galactic nucleus (AGN), as the lack of a broad component in the forbidden lines rejects an outflow origin. This hypothesis is supported by the presence of high-ionization lines, as well as a spatial point-source component embedded within a smoother surface brightness profile. The mass of the black hole is log($M_{BH}/M_{\odot})=6.95{\pm}0.37$, and we estimate that it is accreting at 1.2 ($\pm$0.5) x the Eddington limit. The 1-8 $\mu$m photometric spectral energy distribution (SED) from NIRCam and MIRI shows a continuum dominated by starlight and constrains the host galaxy to be massive (log M/M$_{\odot}$~9.5) and highly star-forming (SFR~30 M$_{\odot}$ yr$^{-1}$). Ratios of the strong emission lines show that the gas in this galaxy is metal-poor (Z/Z$_{\odot}$~0.1), dense (n$_{e}$~10$^{3}$ cm$^{-3}$), and highly ionized (log U~-2.1), consistent with the general galaxy population observed with JWST at high redshifts. We use this presently highest-redshift AGN discovery to place constraints on black hole seeding models and find that a combination of either super-Eddington accretion from stellar seeds or Eddington accretion from massive black hole seeds is required to form this object by the observed epoch., Comment: 26 pages, 14 figures, 6 tables, published in ApJL

Using recent empirical constraints on the dark matter halo--galaxy--supermassive black hole (SMBH) connection from $z=0-7$, we infer how undermassive, typical, and overmassive SMBHs contribute to the quasar luminosity function (QLF) at $z=6$. We find that beyond $L_\mathrm{bol} = 5 \times 10^{46}$ erg/s, the $z=6$ QLF is dominated by SMBHs that are at least 0.3 dex above the $z=6$ median $M_\bullet-M_*$ relation. The QLF is dominated by typical SMBHs (i.e., within $\pm 0.3$ dex around the $M_\bullet-M_*$ relation) at $L_\mathrm{bol} \lesssim 10^{45}$ erg/s. At $z\sim 6$, the intrinsic $M_\bullet-M_*$ relation for all SMBHs is slightly steeper than the $z=0$ scaling, with a similar normalization at $M_* \sim 10^{11} M_\odot$. We also predict the $M_\bullet-M_*$ relation for $z=6$ bright quasars selected by different bolometric luminosity thresholds, finding very good agreement with observations. For quasars with $L_\mathrm{bol} > 3 \times 10^{46}$ ($10^{48}$) erg/s, the scaling relation is shifted upwards by $\sim0.35$ (1.0) dex for $10^{11} M_\odot$ galaxies. To accurately measure the intrinsic $M_\bullet-M_*$ relation, it is essential to include fainter quasars with $L_\mathrm{bol} \lesssim 10^{45}$ erg/s. At high redshifts, low-luminosity quasars are thus the best targets for understanding typical formation paths for SMBHs in galaxies., Comment: 5 pages, 3 figures. Submitted to MNRAS Letters. Comments welcome!

We present CEERS JWST/NIRCam imaging of a massive galaxy group at z=1.85, to explore the early JWST view on massive group formation in the distant Universe. The group contains >16 members (including 6 spectros. confirmations) down to log10(Mstar/Msun)=8.5, including the brightest group galaxy (BGG) in the process of actively assembling at this redshift. The BGG is comprised of multiple merging components extending ~3.6" (30kpc) across the sky. The BGG contributes 69% of the group's total galactic stellar mass, with one of the merging components containing 76% of the total mass of the BGG and a SFR>1810Msun/yr. Most importantly, we detect intra-halo light (IHL) in several HST and JWST/NIRCam bands, allowing us to construct a state-of-the-art rest-frame UV-NIR Spectral Energy Distribution of the IHL for the first time at this high redshift. This allows stellar population characterisation of both the IHL and member galaxies, as well as the morphology distribution of group galaxies vs. their star-formation activity when coupled with Herschel data. We create a stacked image of the IHL, giving us a sensitivity to extended emission of 28.5 mag/arcsec2 at rest-frame 1um. We find that the IHL is extremely dust poor (Av~0), containing an evolved stellar population of log10(t50/yr)=8.8, corresponding to a formation epoch for 50% of the stellar material 0.63Gyr before z=1.85. There is no evidence of ongoing star-formation in the IHL. The IHL in this group at z=1.85 contributes ~10% of the total stellar mass, comparable with what is observed in local clusters. This suggests that the evolution of the IHL fraction is more self-similar with redshift than predicted by some models, challenging our understanding of IHL formation during the assembly of high-redshift clusters. JWST is unveiling a new side of group formation at this redshift, which will evolve into Virgo-like structures in the local Universe., Comment: 14 pages + appendix, 11 figures, 4 tables. Accepted to A&A on 15th May 2023

We present JWST NIRSpec spectroscopy for 11 galaxy candidates with photometric redshifts of $z\simeq9-13$ and $M_{\rm\,UV} \in[-21,-18]$ newly identified in NIRCam images in the Cosmic Evolution Early Release Science (CEERS) Survey. We confirm emission line redshifts for 7 galaxies at $z=7.762-8.998$ using spectra at $\sim1-5\mu$m either with the NIRSpec prism or its three medium resolution gratings. For $z\simeq9$ photometric candidates, we achieve a high confirmation rate of $\simeq$90\%, which validates the classical dropout selection from NIRCam photometry. No robust emission lines are identified in three galaxy candidates at $z>10$, where the strong [OIII] and H$\beta$ lines would be redshifted beyond the wavelength range observed by NIRSpec, and the Lyman-$\alpha$ continuum break is not detected with the current sensitivity. Compared with HST-selected bright galaxies ($M_{\rm\,UV}\simeq-22$) that are similarly spectroscopically confirmed at $z\gtrsim8$, these NIRCam-selected galaxies are characterized by lower star formation rates (SFR$\simeq4\,M_{\odot}$~yr$^{-1}$) and lower stellar masses ($\simeq10^{8}\,M_{\odot}$), but with higher [OIII]+H$\beta$ equivalent widths ($\simeq$1100$\r{A}$), and elevated production efficiency of ionizing photons ($\log(\xi_{\rm\,ion}/{\rm\,Hz\,erg}^{-1})\simeq25.8$) induced by young stellar populations ($<10$~Myrs) accounting for $\simeq20\%$ of the galaxy mass, highlighting the key contribution of faint galaxies to cosmic reionization. Taking advantage of the homogeneous selection and sensitivity, we also investigate metallicity and ISM conditions with empirical calibrations using the [OIII]/H$\beta$ ratio. We find that galaxies at $z\sim8-9$ have higher SFRs and lower metallicities than galaxies at similar stellar masses at $z\sim2-6$, which is generally consistent with the current galaxy formation and evolution models., Comment: 24 pages, 12 figures, 2 tables. ApJL Focus Issue in press

We present a photometric halo mass estimation technique for local galaxies that enables us to establish the stellar mass-halo mass (SMHM) relation down to stellar masses of 10$^5$ M$_\odot$. We find no detectable differences among the SMHM relations of four local galaxy clusters or between the cluster and field relations and we find agreement with extrapolations of previous SMHM relations derived using abundance matching approaches. We fit a power law to our empirical SMHM relation and find that for adopted NFW dark matter profiles and for M$_* < 10^9$ M$_\odot$, the halo mass is M$_h = 10^{10.35\pm0.02}({\rm M}_*/10^8 {\rm M}_\odot)^{0.63\pm0.02}$. The normalisation of this relation is susceptible to systematic modelling errors that depend on the adopted dark matter potential and the quoted uncertainties refer to the uncertainties in the median relation. For galaxies with M$_* < 10^{9}$ M$_\odot$ that satisfy our selection criteria, the scatter about the fit in $M_h$, including uncertainties arising from our methodology, is 0.3 dex. Finally, we place lower luminosity Local Group galaxies on the SMHM relationship using the same technique, extending it to M$_* \sim 10^3$ M$_\odot$ and suggest that some of these galaxies show evidence for additional mass interior to the effective radius beyond that provided by the standard dark matter profile. If this mass is in the form of a central black hole, the black hole masses are in the range of intermediate mass black holes, $10^{(5.7\pm0.6)}$ M$_\odot$, which corresponds to masses of a few percent of M$_h$, well above values extrapolated from the relationships describing more massive galaxies., Comment: Accepted for publication in MNRAS; 13 pages

Physical layer key generation (PLKG) can significantly enhance the security of classic encryption schemes by enabling them to change their secret keys significantly faster and more efficient. However, due to the reliance of PLKG techniques on channel medium, reaching a high secret key rate is challenging in static environments. Recently, exploiting intelligent reflecting surface (IRS) as a means to induce randomness in static wireless channels has received significant research interest. However, the impact of spatial correlation between the IRS elements is rarely studied. To be specific, for the first time, in this contribution, we take into account a spatially correlated IRS which intends to enhance the secret key generation (SKG) rate in a static medium. Closed form analytical expressions for SKG rate are derived for the two cases of random phase shift and equal random phase shift for all the IRS elements. We also analyze the temporal correlation between the channel samples to ensure the randomness of the generated secret key sequence. We further formulate an optimization problem in which we determine the optimal portion of time within a coherence interval dedicated for the direct and indirect channel estimation. We show the accuracy and the fast convergence of our proposed sequential convex programming (SCP) based algorithm and discuss the various parameters affecting spatially correlated IRS assisted PLKG.

Recently, simultaneously transmitting and reflecting reconfigurable intelligent surfaces (STAR-RISs) have emerged as a novel technology that provides 360 coverage and new degrees-of-freedom (DoFs). They are also capable of manipulating signal propagation and simultaneous wireless information and power transfer (SWIPT). This paper introduces a novel STAR-RIS-aided secure SWIPT system for downlink multiple input single output rate-splitting multiple access (RSMA) networks. The transmitter concurrently communicates with the information receivers (IRs) and sends energy to untrusted energy receivers (UERs). The UERs are also capable of wiretapping the IR streams. We assume that the channel state information (CSI) of the IRs is known at the information transmitter, but only imperfect CSI for the UERs is available at the energy transmitter. By exploiting RSMA, the base station splits the messages of the IRs into common and private parts. The former is encoded into a common stream that can be decoded by all IRs, while the private messages are individually decoded by their respective IRs. We find the precoders and STAR-RIS configuration that maximizes the achievable worst-case sum secrecy rate of the IRs under a total transmit power constraint, a sum energy constraint for the UERs, and subject to constraints on the transmission and reflection coefficients. The formulated problem is non-convex and has intricately coupled variables. To tackle this challenge, a suboptimal two-step iterative algorithm based on the sequential parametric convex approximation method is proposed. Simulations demonstrate that the RSMA-based algorithm implemented with a STAR-RIS enhances both the rate of confidential information transmission and the total spectral efficiency. Furthermore, our method surpasses the performance of both orthogonal multiple access (OMA) and non-OMA (NOMA)., Comment: 16 pages, journal paper

We present an investigation into the first 500 Myr of galaxy evolution from the Cosmic Evolution Early Release Science (CEERS) survey. CEERS, one of 13 JWST ERS programs, targets galaxy formation from z~0.5 to z>10 using several imaging and spectroscopic modes. We make use of the first epoch of CEERS NIRCam imaging, spanning 35.5 sq. arcmin, to search for candidate galaxies at z>9. Following a detailed data reduction process implementing several custom steps to produce high-quality reduced images, we perform multi-band photometry across seven NIRCam broad and medium-band (and six Hubble broadband) filters focusing on robust colors and accurate total fluxes. We measure photometric redshifts and devise a robust set of selection criteria to identify a sample of 26 galaxy candidates at z~9-16. These objects are compact with a median half-light radius of ~0.5 kpc. We present an early estimate of the z~11 rest-frame ultraviolet (UV) luminosity function, finding that the number density of galaxies at M_UV ~ -20 appears to evolve very little from z~9 to z~11. We also find that the abundance (surface density [arcmin^-2]) of our candidates exceeds nearly all theoretical predictions. We explore potential implications, including that at z>10 star formation may be dominated by top-heavy initial mass functions, which would result in an increased ratio of UV light per unit halo mass, though a complete lack of dust attenuation and/or changing star-formation physics may also play a role. While spectroscopic confirmation of these sources is urgently required, our results suggest that the deeper views to come with JWST should yield prolific samples of ultra-high-redshift galaxies with which to further explore these conclusions., Comment: Replaced with published version

Large language models (LLMs) have been shown to be able to perform new tasks based on a few demonstrations or natural language instructions. While these capabilities have led to widespread adoption, most LLMs are developed by resource-rich organizations and are frequently kept from the public. As a step towards democratizing this powerful technology, we present BLOOM, a 176B-parameter open-access language model designed and built thanks to a collaboration of hundreds of researchers. BLOOM is a decoder-only Transformer language model that was trained on the ROOTS corpus, a dataset comprising hundreds of sources in 46 natural and 13 programming languages (59 in total). We find that BLOOM achieves competitive performance on a wide variety of benchmarks, with stronger results after undergoing multitask prompted finetuning. To facilitate future research and applications using LLMs, we publicly release our models and code under the Responsible AI License.

The new capabilities that JWST offers in the near- and mid-infrared (IR) are used to investigate in unprecedented detail the nature of optical/near-IR faint, mid-IR bright sources, HST-dark galaxies among them. We gather JWST data from the CEERS survey in the EGS, jointly with HST data, and analyze spatially resolved optical-to-mid-IR spectral energy distributions (SEDs) to estimate both photometric redshifts in 2 dimensions and stellar populations properties in a pixel-by-pixel basis. We select 138 galaxies with F150W-F356W>1.5 mag, F356W<27.5 mag. The nature of these sources is threefold: (1) 71% are dusty star-forming galaxies at 2100 Gyr^-1); (2) 18% are quiescent/dormant (i.e., subject to reignition and rejuvenation) galaxies at 3

We present a comprehensive analysis of the evolution of the morphological and structural properties of a large sample of galaxies at z=3-9 using early JWST CEERS NIRCam observations. Our sample consists of 850 galaxies at z>3 detected in both CANDELS HST imaging and JWST CEERS NIRCam images to enable a comparison of HST and JWST morphologies. Our team conducted a set of visual classifications, with each galaxy in the sample classified by three different individuals. We also measure quantitative morphologies using the publicly available codes across all seven NIRCam filters. Using these measurements, we present the fraction of galaxies of each morphological type as a function of redshift. Overall, we find that galaxies at z>3 have a wide diversity of morphologies. Galaxies with disks make up a total of 60\% of galaxies at z=3 and this fraction drops to ~30% at z=6-9, while galaxies with spheroids make up ~30-40% across the whole redshift range and pure spheroids with no evidence for disks or irregular features make up ~20%. The fraction of galaxies with irregular features is roughly constant at all redshifts (~40-50%), while those that are purely irregular increases from ~12% to ~20% at z>4.5. We note that these are apparent fractions as many selection effects impact the visibility of morphological features at high redshift. The distributions of S\'ersic index, size, and axis ratios show significant differences between the morphological groups. Spheroid Only galaxies have a higher S\'ersic index, smaller size, and higher axis ratio than Disk/Irregular galaxies. Across all redshifts, smaller spheroid and disk galaxies tend to be rounder. Overall, these trends suggest that galaxies with established disks and spheroids exist across the full redshift range of this study and further work with large samples at higher redshift is needed to quantify when these features first formed., Comment: Accepted for publication to ApJL, 24 pages, 14 figures

The Nancy Grace Roman Space Telescope, NASA's next flagship observatory, will redefine deep-field galaxy survey with a field of view two orders of magnitude larger than Hubble and an angular resolution of matching quality. These future deep-wide galaxy surveys necessitate new simulations to forecast their scientific output and to optimise survey strategies. In this work, we present five realizations of 2-deg^2 lightcones, containing a total of >25 million simulated galaxies with -16 < MUV < -25 spanning z ~ 0 to 10. This dataset enables a new set of experiments with the impacts of survey size on the derived galaxy formation and cosmological constraints. The intrinsic and observable galaxy properties are predicted using a well-established, physics-based semi-analytic modelling approach. We provide forecasts for number density, cosmic SFR, field-to-field variance, and angular two-point correlation functions, and demonstrate how the future wide-field surveys will be able to improve these measurements relative to current generation surveys. We also present a comparison between these lightcones and others that have been constructed with empirical models. The mock lightcones are designed to facilitate the exploration of multi-instrument synergies and connecting with current generation instruments and legacy surveys. In addition to Roman, we also provide photometry for a number of other instruments on upcoming facilities, including Euclid and Rubin, as well as the instruments that are part of many legacy surveys. Full object catalogues and data tables for the results presented in this work are made available through a web-based, interactive portal https://www.simonsfoundation.org/semi-analytic-forecasts., Comment: 25 pages, 16 figures. Accepted for publication in MNRAS

The Cooperative Rate-Splitting (CRS) scheme, proposed evolves from conventional Rate Splitting (RS) and relies on forwarding a portion of the RS message by the relaying users. In terms of secrecy enhancement, it has been shown that CRS outperforms its non-cooperative counterpart for a two-user Multiple Input Single Output (MISO) Broadcast Channel (BC). Given the massive connectivity requirement of 6G, we have generalized the existing secure two-user CRS framework to the multi-user framework, where the highest-security users must be selected as the relay nodes. This paper addresses the problem of maximizing the Worst-Case Secrecy Rate (WCSR) in a UAV-aided downlink network where a multi-antenna UAV Base-Station (UAV-BS) serves a group of users in the presence of an external eavesdropper (Eve). We consider a practical scenario in which only imperfect channel state information of Eve is available at the UAV-BS. Accordingly, we conceive a robust and secure resource allocation algorithm, which maximizes the WCSR by jointly optimizing both the Secure Relaying User Selection (SRUS) and the network parameter allocation problem, including the RS transmit precoders, message splitting variables, time slot sharing and power allocation. To circumvent the resultant non-convexity owing to the discrete variables imposed by SRUS, we propose a two-stage algorithm where the SRUS and network parameter allocation are accomplished in two consecutive stages. With regard to the SRUS, we study both centralized and distributed protocols. On the other hand, for jointly optimizing the network parameter allocation we resort to the Sequential Parametric Convex Approximation (SPCA) algorithm. Our numerical results show that the proposed solution significantly outperforms the existing benchmarks for a wide range of network loads in terms of the WCSR., Comment: arXiv admin note: text overlap with arXiv:1910.07843 by other authors