Showing papers on "Shadow (psychology) published in 2022"
TL;DR: A review of the current state of the research of the black hole shadow, focusing on analytical (as opposed to numerical and observational) studies can be found in this article , with particular attention to the definition of the shadow and its relation to the often used concepts of escape cone, critical impact parameter and particle cross-section.
106 citations
TL;DR: Wang et al. as discussed by the authors proposed a multilevel feature enhanced network for cloud/shadow segmentation, where ResNet-18 is used as the backbone to extract all levels of semantic information, and Feature Enhancement Module is proposed to strengthen the feature information to obtain more effective feature information.
Abstract: ABSTRACT In the application of remote sensing, cloud blocking brings trouble to the analysis of surface parameters and atmospheric parameters. Due to the complexity of the background, the influence of some cloud-like interferences (such as ice, snow, buildings, etc.) and the complexity of the cloud shape, the traditional deep learning method is difficult to segment the edge information of cloud and cloud shadow accurately, resulting in misjudgement at the edge. In order to solve these problems, a multilevel feature enhanced network is proposed for cloud/shadow segmentation. In this work, ResNet-18 is used as the backbone to extract all levels of semantic information, and Feature Enhancement Module is proposed to strengthen the feature information to obtain more effective feature information. Multiscale Fusion module is constructed to fuses multiscale features of deep information to obtain global feature information while considering local feature information. Finally, through the Feature Guidance module, low-level features are used to guide the high-level features to guide the recovery of spatial information and improve the efficiency of upsampling. On the data collected by Landsat-8, Sentinel-2, and HRC_WHU data set, the experimental results show that this method is superior to the existing methods.
38 citations
TL;DR: In this article , the inner disk geometries of 20 well-known transition disks with VLTI/GRAVITY observations were derived from the ALMA velocity maps and compared to inner disk constraints.
Abstract: For several transition disks (TDs), dark regions interpreted as shadows have been observed in scattered light imaging and are hypothesized to originate from misalignments between distinct disk regions. We aim to investigate the presence of misalignments in TDs. We study the inner disk geometries of 20 well-known transition disks with VLTI/GRAVITY observations and use complementary $^{12}$CO and $^{13}$CO molecular line data from ALMA to derive the orientation of the outer disk regions. We fit simple models to the GRAVITY data to derive the inner disks inclination and position angles. The outer disk geometries were derived from Keplerian fits to the ALMA velocity maps and compared to the inner disk constraints. We also predicted the locations of shadows for significantly misaligned systems. Our analysis reveals six disks to exhibit significant misalignments between their inner and outer disks. The predicted shadow positions agree well with the scattered light images of HD100453 and HD142527, and we find supporting evidence for a shadow in the disk around CQ Tau. In the other three targets for which we infer significantly misaligned disks, V1247 Ori, V1366 Ori, and RY Lup, we do not see any evident sign of shadows in the scattered light images. The scattered light shadows observed in DoAr44, HD135344B, and HD139614 are consistent with our observations, yet the underlying morphology is likely too complex to be described by our models and the accuracy achieved by our observations. Whereas we can derive precise constraints on the potential shadow positions for well-resolved inner disks around HAeBe stars, the statistical uncertainties for the marginally resolved inner disks around the TTS of our sample make it difficult to extract conclusive constraints for the presence of shadows in these systems.
27 citations
TL;DR: In this paper , the shadow drift and the variation in the azimuthal angle lapse associated to the photon ring autocorrelation were studied for the supermassive object Sgr A$^\star.
Abstract: Ultralight bosons can affect the dynamics of spinning black holes (BHs) via superradiant instability, which can lead to a time evolution of the supermassive BH shadow. We study prospects for witnessing the superradiance-induced BH shadow evolution, considering ultralight vector and tensor fields. We introduce two observables sensitive to the shadow time-evolution: the shadow drift, and the variation in the azimuthal angle lapse associated to the photon ring autocorrelation. The two observables are shown to be highly complementary, depending on the observer's inclination angle. Focusing on the supermassive object Sgr A$^\star$ we show that both observables can vary appreciably over human timescales of a few years in the presence of superradiant instability, leading to signatures which are well within the reach of the Event Horizon Telescope for realistic observation times (but benefiting significantly from extended observation periods), and paving the way towards probing ultralight bosons in the $\sim 10^{-17}\,{\rm eV}$ mass range.
27 citations
TL;DR: In this article , the authors constructed a charged rotating black hole in 4D EGB gravity using complex coordinate transformations suggested by Newman-Janis, and investigated the shape of the shadow cast by a rotating charged black hole.
26 citations
TL;DR: In this paper , the cosmological constant corrections arising when the dark energy action has the usual form and when dark energy arises from a Weyl scaling invariant action were calculated.
Abstract: We review the equations determining the photon sphere radius and the black hole shadow radius, and calculate the cosmological constant corrections arising when the dark energy action has the usual form, and when dark energy arises from a Weyl scaling invariant dark energy action. For black hole targets of the Event Horizon Telescope, the corrections are very small.
24 citations
TL;DR: Liu et al. as mentioned in this paper summarized the progress and achievements in the cloud and cloud shadow detection methods in terms of features, algorithms, and validation of results, and then discussed existing problems, and provided their prospects.
Abstract: The presence of clouds prevents optical satellite imaging systems from obtaining useful Earth observation information and negatively affects the processing and application of optical satellite images. Therefore, the detection of clouds and their accompanying shadows is an essential step in preprocessing optical satellite images and has emerged as a popular research topic in recent decades due to the interest in image time series analysis and remote sensing data mining. This review first analyzes the trends of the field, summarizes the progress and achievements in the cloud and cloud shadow detection methods in terms of features, algorithms, and validation of results, and then discusses existing problems, and provides our prospects at the end. We aim at identifying the emerging research trends and opportunities, while providing guidance for selecting the most suitable methods for coping with cloud contaminated problems faced by optical satellite images, an extremely important issue for remote sensing of cloudy and rainy areas. In the future, expected improvements in accuracy and generalizability, the combination of physical models and deep learning, as well as artificial intelligence and online big data processing platforms will be able to further promote processing efficiency and facilitate applications of image time series. In addition, this review collects the latest open-source tools and datasets for cloud and cloud shadow detection and launches an online project (Open Satellite Image Cloud Detection Resources, i.e., OpenSICDR) to share the latest research outputs ( https://github.com/dr-lizhiwei/OpenSICDR ).
24 citations
TL;DR: In this article , the authors developed a model of investigating the link between the level of shadow economy and indicators of social development of the country to identify the risks of the shadow economy for social indicators of macroeconomic stability.
Abstract: Purpose. To develop a model of investigating the link between the level of shadow economy and indicators of social development of the country. Methodology. The study of the relationship between the analyzed indicators was conducted using general and special research methods. The established hypotheses were tested using VAR/VEC modeling. Dickey-Fuller test, the Phillips-Perron test, Joansen test are used in the work. Findings. The paper identifies the risks of the shadow economy for social indicators of macroeconomic stability. Based on the analysis of the countrys social development indicators, indicators were identified that are most sensitive to changes in the level of the shadow economy which are: Gini coefficient, average income ratio of 10% of the richest to 10% of the poorest, average income ratio of 20% of the richest to 20% of the poorest sections of the population, Human Development Index, gross average wage. The EU countries and Ukraine are identified as the statistical base of the study and the assessment period is 20052020. The results of modeling proved the relationship between the level of shadow economy and indicator of social development. Originality. The approach to assessing the relationship between the level of the shadow economy and indicators of social development of the country by considering the indicators that most fully characterize the level of social protection and material well-being of the population has been improved. Practical value. The scientific contribution of the paper is that existing research on the impact of shadow economy on the level of social development of the countries remains fragmented, as well as studies assessing its effect on the macroeconomic stability. The impulse response function constructed by the authors may provide some insight into better understanding of the indicators of social development, the most sensitive to the shadow economy shocks. The results of estimation can be used for practical or scientific purposes.
22 citations
TL;DR: In this paper , the authors use classical shadows and randomized measurements to circumvent the need for coherent access to multiple copies at an exponential cost and find that the overhead is still favorable compared to full state tomography.
Abstract: Mitigating errors in quantum information processing devices is especially important in the absence of fault tolerance. An effective method in suppressing state-preparation errors is using multiple copies to distill the ideal component from a noisy quantum state. Here, we use classical shadows and randomized measurements to circumvent the need for coherent access to multiple copies at an exponential cost. We study the scaling of resources using numerical simulations and find that the overhead is still favorable compared to full state tomography. We optimize measurement resources under realistic experimental constraints and apply our method to an experiment preparing Greenberger-Horne-Zeilinger (GHZ) state with trapped ions. In addition to improving stabilizer measurements, the analysis of the improved results reveals the nature of errors affecting the experiment. Hence, our results provide a directly applicable method for mitigating errors in near-term quantum computers.
18 citations
TL;DR: In this article , shadow care infrastructures is a new frame for conceptualizing the complex and interconnected practices through which marginalised people seek survival in urban poverty in the global north.
Abstract: Economic restructuring and welfare reform are driving new forms of urban poverty in the global north. Shadow care infrastructures is a new frame for conceptualising the complex and interconnected practices through which marginalised people seek survival in this context. It remaps welfare landscapes across a continuum that includes formal and informal, established and improvised practice, the not-for-profit sector, informal community networks and exchange and the black market. Conceptually, it centres the care practices that sustain life and the infrastructures that sustain them. Activating a ‘shadow geographies’ tradition it foregrounds care infrastructures that are necessary, but rarely visible within, welfare discourse.
TL;DR: In this article , the authors examined the impact of financial inclusion and shadow economy on the economic growth of developing economies over the period 2008-2017 and concluded that financial inclusion has positive and significant impact on economic growth.
TL;DR: In this paper , the cosmological constant corrections arising when the dark energy action has the usual form and when dark energy arises from a Weyl scaling invariant action were calculated.
Abstract: We review the equations determining the photon sphere radius and the black hole shadow radius, and calculate the cosmological constant corrections arising when the dark energy action has the usual form, and when dark energy arises from a Weyl scaling invariant dark energy action. For black hole targets of the Event Horizon Telescope, the corrections are very small.
TL;DR: In this paper , the authors investigated the importance of remote sensing data for different land cover (LC) classes such as agriculture, forest, grassland, water, urban, and natural-seminatural.
Abstract: The increasing availability and variety of global satellite products provide a new level of data with different spatial, temporal, and spectral resolutions; however, identifying the most suited resolution for a specific application consumes increasingly more time and computation effort. The region’s cloud coverage additionally influences the choice of the best trade-off between spatial and temporal resolution, and different pixel sizes of remote sensing (RS) data may hinder the accurate monitoring of different land cover (LC) classes such as agriculture, forest, grassland, water, urban, and natural-seminatural. To investigate the importance of RS data for these LC classes, the present study fuses NDVIs of two high spatial resolution data (high pair) (Landsat (30 m, 16 days; L) and Sentinel-2 (10 m, 5–6 days; S), with four low spatial resolution data (low pair) (MOD13Q1 (250 m, 16 days), MCD43A4 (500 m, one day), MOD09GQ (250 m, one-day), and MOD09Q1 (250 m, eight day)) using the spatial and temporal adaptive reflectance fusion model (STARFM), which fills regions’ cloud or shadow gaps without losing spatial information. These eight synthetic NDVI STARFM products (2: high pair multiply 4: low pair) offer a spatial resolution of 10 or 30 m and temporal resolution of 1, 8, or 16 days for the entire state of Bavaria (Germany) in 2019. Due to their higher revisit frequency and more cloud and shadow-free scenes (S = 13, L = 9), Sentinel-2 (overall R2 = 0.71, and RMSE = 0.11) synthetic NDVI products provide more accurate results than Landsat (overall R2 = 0.61, and RMSE = 0.13). Likewise, for the agriculture class, synthetic products obtained using Sentinel-2 resulted in higher accuracy than Landsat except for L-MOD13Q1 (R2 = 0.62, RMSE = 0.11), resulting in similar accuracy preciseness as S-MOD13Q1 (R2 = 0.68, RMSE = 0.13). Similarly, comparing L-MOD13Q1 (R2 = 0.60, RMSE = 0.05) and S-MOD13Q1 (R2 = 0.52, RMSE = 0.09) for the forest class, the former resulted in higher accuracy and precision than the latter. Conclusively, both L-MOD13Q1 and S-MOD13Q1 are suitable for agricultural and forest monitoring; however, the spatial resolution of 30 m and low storage capacity makes L-MOD13Q1 more prominent and faster than that of S-MOD13Q1 with the 10-m spatial resolution.
TL;DR: A conceptual model for smart digital forensic readiness of organizations with shadow IoT devices is developed, which will serve as a prototype for IoT device identification, IoT device monitoring, as well as digital potential evidence capturing and preservation for forensic readiness.
Abstract: Internet of Things (IoT) is the network of physical objects for communication and data sharing. However, these devices can become shadow IoT devices when they connect to an existing network without the knowledge of the organization’s Information Technology team. More often than not, when shadow devices connect to a network, their inherent vulnerabilities are easily exploited by an adversary and all traces are removed after the attack or criminal activity. Hence, shadow connections pose a challenge for both security and forensic investigations. In this respect, a forensic readiness model for shadow device-inclusive networks is sorely needed for the purposes of forensic evidence gathering and preparedness, should a security or privacy breach occur. However, the hidden nature of shadow IoT devices does not facilitate the effective adoption of the most conventional digital and IoT forensic methods for capturing and preserving potential forensic evidence that might emanate from shadow devices in a network. Therefore, this paper aims to develop a conceptual model for smart digital forensic readiness of organizations with shadow IoT devices. This model will serve as a prototype for IoT device identification, IoT device monitoring, as well as digital potential evidence capturing and preservation for forensic readiness.
TL;DR: In this article , a hierarchical framework was proposed for IS mapping at the city scale by synergetic fusion of dual polarized SAR and multispectral information. But, the proposed method performed well on the urban area with abundant shadows, with an Overall Accuracy (OA) of 93.9% and a Kappa coefficient of 0.92 achieved.
Abstract: The combined use of the data from Sentinel-1 (S1) dual-polarized Synthetic Aperture Radar (SAR) and Sentinel-2 (S2) Multispectral Sensor Images (MSI) has been successfully applied in many remote sensing applications. However, when it comes to the mapping of impervious surface (IS), the non-negligible shadows on S2 images can severely degrade the mapping accuracy. How to effectively incorporate S1 and S2 data to precisely extract IS from cities has not been well investigated yet. Besides, it still remains challenging to extract appropriate polarimetric features of S1 to discriminate IS and supplement the drawbacks of S2. In this research, we explore more effective polarimetric features of S1 and propose a hierarchical framework for IS mapping at the city scale by synergetic fusion of dual polarized SAR and multispectral information. The new polasrimetric features of S1 is initially explored based on the backscattering mechanism of dual polarized SAR. Then the IS is identified from shadow-free and shadow areas in two consecutive steps with different feature sets. The result indicates that our new polarimetric features of S1, i.e., the diagonal elements of coherence matrix, are more suitable for IS mapping due to their associated physical meaning with different land covers. With suitable feature sets, our proposed methods performed well on the urban area with abundant shadows, with an Overall Accuracy (OA) of 93.9% and a Kappa coefficient of 0.92 achieved.
TL;DR: In this article , a qualitative study with a reflective lifeworld approach was conducted to gain a deeper understanding of how women not infected by SARS-CoV-2 experienced pregnancy during the COVID-19 pandemic in Sweden.
TL;DR: In this article , the authors summarized the arguments and counterarguments within the scientific discussion on improving public administration tools in the context of implementing innovative mechanisms for combating shadow financial transactions and formalized innovative strategies to counter the shadow withdrawal of capital with the participation of financial intermediaries.
Abstract: This article summarizes the arguments and counterarguments within the scientific discussion on improving public administration tools in the context of implementing innovative mechanisms for combating shadow financial transactions. The main purpose of this research is to formalize innovative strategies to counter the shadow withdrawal of capital with the participation of financial intermediaries. The systematization of scientific sources and approaches to solving the problem of the de-shadow economy proved that a characteristic feature of the functioning of the shadow market is the active participation of financial intermediaries in shadow operations. The information base is data from the World Bank and the Organization for Economic Cooperation and Development, the Group for the Development of Financial Measures to Combat Money Laundering, Transparency International, and the World Economic Forum. The period of the study is 2003-2021. The EU countries, Ukraine, Moldova, and Montenegro, as candidate countries for EU membership, were selected as the object of the study. This study applied the methods of bibliometric analysis to generalize the existing scientific work on the investigated issue, analysis of changes in the number of search changes on the problems of shadowing the economy, and clustering regions by the number of search queries on the shadow economy. Intellectual data analysis methods (one-dimensional branching CART and agglomeration methods) were used for clustering countries depending on the nature of the policy of countering the shadowing of the economy. Based on the results of the bibliometric analysis, theories describing the shadow economy, in particular: innovation theory, the theory of centralization, and institutional theory, were summarized. The article presents the results of cluster analysis, which proved the practicality of selecting three clusters of countries: cluster 1 – Cyprus, Czech Republic, Denmark, Finland, Greece, Ireland, Italy, Luxembourg, and Portugal; cluster 2 – Bulgaria, Croatia, Estonia, France, Malta, Netherlands, Spain, Sweden, Belgium, Greece, Austria, Hungary, and Slovak Republic, Slovenia; cluster 3 – Lithuania, Latvia, Romania, Poland, Moldova, Montenegro, and Ukraine. The study empirically confirmed and theoretically proved that the entire set of innovative scenarios for implementing economic de-shadowing policy could be divided into three types (evolutionary scenario, sequential transformation scenario, and forced scenario). The above scenarios depend on the speed of change in the indicators of developing the shadow economic sector and their sensitivity to the implemented measures.
TL;DR: In this article , the authors analyzed the effects of corruption and institutional quality on shadow economy to test the hypothesis of greasing and sanding the wheels of corruption by empirically studying 29 Asian countries.
Abstract: This study analyzes the effects of corruption and institutional quality on shadow economy to test the hypothesis of greasing and sanding the wheels of corruption. After empirically studying 29 Asian countries, our results indicate that corruption and institutional quality have a positive and negative impact on shadow economy, respectively. Furthermore, the interaction of corruption and economic freedom has a negative impact on shadow economy, whereas corruption and democracy have a positive impact on shadow economy, confirming that corruption works better to ‘grease of the wheels’ in weak economic institutions conditions and in strong political institutions conditions.
TL;DR: In this article , a deep learning-based method for cloud/shadow-covered missing data reconstruction for time-series Landsat images is proposed, which combines the combined use of autoencoder, long-short-term memory (AE-LSTM)-based similar pixel clustering and for backward LSTM-based time series prediction.
Abstract: ABSTRACT Reconstructing the missing data for cloud/shadow-covered optical satellite images has great significance for enhancing the data availability and multi-temporal analysis. In this study, we proposed a deep-learning-based method for cloud/shadow-covered missing data reconstruction for time-series Landsat images. Central to this method is the combined use of autoencoder, long-short-term memory (AE-LSTM)-based similar pixel clustering and for backward LSTM-based time-series prediction. First, manually delineated cloud/shadow-covered masks were overlaid onto multi-temporal satellite images to produce pixel-wise time-series data with masking values. Second, these pixel-wise time series were clustered by an AE-LSTM-based unsupervised method into multiple clusters, for searching similar pixels. Third, for each cluster of target images, a for-backward-LSTM-based model was established to restore missing values in time series data. Finally, reconstructed data were merged with cloud-free (image) regions to produce cloud-free time-series images. The proposed method was applied onto three datasets of multi-temporal Landsat-8 OLI images to restore cloud/shadow-covered images. The reconstruction results, showing an improvement of greater than 10% in normalized mean-square error compared to the state-of-the-art methods, demonstrated the effectiveness of the proposed method in time-series reconstruction for satellite images.
TL;DR: In this article , the authors analyse user discussions on shadow banning, a controversial, potentially non-existing form of content moderation on popular social media platforms, and argue that discursive mobilisations of the term can act as a methodological entry point to studying the shifting grounds and emerging logics of algorithmic governance.
Abstract: In this paper, I approach platform governance through algorithmic folklore, consisting of beliefs and narratives about moderation systems that are passed on informally and can exist in tension with official accounts. More specifically, I analyse user discussions on ‘shadow banning’, a controversial, potentially non-existing form of content moderation on popular social media platforms. I argue that discursive mobilisations of the term can act as a methodological entry point to studying the shifting grounds and emerging logics of algorithmic governance, not necessarily in terms of the actual practices themselves, but in terms of its experiential dimension that, in turn, indicates broader modalities and relationalities of control. Based on my analysis of the user discussions, I argue that the constitutive logics of social media platforms increasingly seem to run counter to the values of good governance, such as clarity and stability of norms, and consistency of enforcement. This is reflected in how users struggle, desperately, to form expectations about system operation and police themselves according to perceived rules, yet are left in a state of dependency and frustration, unable to take hold of their digital futures.
TL;DR: In this article , the authors investigated the shadow and photon sphere of the black bole in clouds of strings and quintessence with static and infalling spherical accretions, and they obtained the geodesics of the photons near a black hole with different impact parameters.
Abstract: In this study, we investigate the shadow and photon sphere of the black bole in clouds of strings and quintessence with static and infalling spherical accretions. We obtain the geodesics of the photons near a black hole with different impact parameters b to investigate how the string cloud model and quintessence influence the specific intensity by altering the geodesic and the average radial position of photons. In addition, the range of the string cloud parameter a is constrained to ensure that a shadow can be observed. Moreover, the light sources in the accretion follow a normal distribution with an attenuation factor γ, and we adopt a model of the photon emissivity to obtain the specific intensities. Furthermore, the shadow with static spherical accretion is plotted, which demonstrates that the apparent shape of the shadow is a perfect circle, and the value of γ influences the brightness of the photon sphere. Subsequently, we investigate the profile and specific intensity of the shadows with static and infalling spherical accretions, respectively. The interior of the shadows with an infalling spherical accretion will be darker than that with the static spherical accretion, and the specific intensity with both static and infalling spherical accretions gradually converges.
TL;DR: In this article , a real-time shadow model of the building complex and an STPVG system power generation model with the shadows of the surrounding buildings are developed and validated, and the models are used to simulate and analyze the influence of building shadow on the performance of the STPVM system.
TL;DR: In this article , the authors consider how the coronavirus disease (COVID-19) created a significant policy window and explore the conditions under which policy change occurs and when it sticks.
TL;DR: This work proposes a new shadow illumination model, which ensures the identity mapping among unshaded regions, and adaptively performs fine grained spatial mapping between shadow regions and their references, and reformulates the shadow removal task as a variational optimization problem.
Abstract: Deep Convolutional Neural Networks (CNNs) based methods have achieved significant breakthroughs in the task of single image shadow removal. However, the performance of these methods remains limited for several reasons. First, the existing shadow illumination model ignores the spatially variant property of the shadow images, hindering their further performance. Second, most deep CNNs based methods directly estimate the shadow free results from the input shadow images like a black box, thus losing the desired interpretability. To address these issues, we first propose a new shadow illumination model for the shadow removal task. This new shadow illumination model ensures the identity mapping among unshaded regions, and adaptively performs fine grained spatial mapping between shadow regions and their references. Then, based on the shadow illumination model, we reformulate the shadow removal task as a variational optimization problem. To effectively solve the variational problem, we design an iterative algorithm and unfold it into a deep network, naturally increasing the interpretability of the deep model. Experiments show that our method could achieve SOTA performance with less than half parameters, one-fifth of floating-point of operations (FLOPs), and over seventeen times faster than SOTA method (DHAN).
TL;DR: In this paper , the authors showed that shadow from surrounding buildings affects the energy generation but the impact of shadow is generally limited and only buildings of less than 3 storeys might suffer serious shadow covering and those higher than this mainly reduce their productivity by only about 1%.
TL;DR: In this paper , the authors investigated the ability of current and future very long baseline interferometers to estimate the physical parameters of the black hole spacetime and accretion disk using two different parametrized black hole metrics that encode a number of possible deviations from Kerr.
Abstract: The black hole shadow, first observed by the Event Horizon Telescope in 2017, is the newest method for studying black holes and understanding gravity. Much work has gone into understanding the shadow of a Kerr black hole, including all of the complex astrophysics of the accretion disk, and there are numerous studies of the ideal shadow in non-Kerr black holes and exotic compact objects. This paper presents one of the first studies of the black hole shadow of non-Kerr black holes when the illumination source is an accretion disk. In particular, the ability of current and future very long baseline interferometers to estimate the physical parameters of the black hole spacetime and accretion disk is investigated using two different parametrized black hole metrics that encode a number of possible deviations from Kerr. Both the full shadow image and the individual subrings of the shadow are analyzed as the higher order subrings are weakly dependent on the disk physics and may be a more viable observable for studying the spacetime. The results suggest that with current telescope capabilities and any future earth-based telescopes it will be quite difficult to place strong constraints on departures from the Kerr spacetime, primarily due to the low resolution and strong degeneracies between the spacetime parameters. More optimistically, space-based interferometers may be capable of testing the Kerr nature of black holes and general relativity to comparable or better precision than is currently possible with other observations.
TL;DR: Wang et al. as mentioned in this paper examined the effects of adverse childhood experiences (ACEs) on adult entrepreneurial behaviors by adopting the data from China Health and Retirement Longitudinal Study (CHARLS), and found that the shadow of ACEs is significantly detrimental to entrepreneurship in adulthood, and this result proved robust across several methods.
TL;DR: In this article , the shadow of Born-Infeld (BI) black holes with magnetic monopoles and Schwarzschild black holes immersed in the BI uniform magnetic field was studied using backward ray-tracing method.
Abstract: Abstract In this work, we study the shadow of Born–Infeld (BI) black holes with magnetic monopoles and Schwarzschild black holes immersed in the BI uniform magnetic field. Illuminated by a celestial sphere, black hole images are obtained by using the backward ray-tracing method. For magnetically charged BI black holes, we find that the shadow radius increases with the increase of nonlinear electromagnetics effects. For Schwarzschild black holes immersed in the BI uniform magnetic field, photons tend to move towards the axis of symmetric, resulting in stretched shadows along the equatorial plane.