Miracle-dz/UniFAR-FTUs huggingface dataset:
On restrictions and extensions of cusp forms

Let F be a number field. We denote by OF its ring of integers, AF its adèle ring, and for each place v of F , we also denote by Fv the associated completion of F and Ov ⊂ Fv its ring of integers. Let H be a reductive linear algebraic group defined over F . We set H∞ = H(F⊗QR), the direct product of the Lie groups H(Fv) for v Archimedean, and denote by Hf the locally profinite group H(AfF ) where A f F is the F -algebra of finite adèles of F : we have H(AF ) = H∞×Hf . Our main reference for automorphic forms will be Borel-Jacquet’s paper [BJ79]. If c is a character of the center of H(AF ), we denote by Acusp(H)c the space of cuspidal automorphic functions H(AF )→ C with central character c and with respect to a choice of maximal compact subgroup K∞ of H∞ (in the sense of [BJ79, §4.4]). This is an admissible, semi-simple, (LieH∞,K∞)×Hf -module. For short, a (LieH∞,K∞)×Hf module will be called an H(AF )-gk-module. Recall that for any integer m ≥ 1 such that (F,m) is not special in the sense of the statement of the Grunwald-Wang theorem (see [AT, Ch. X]), an element of F is an m-th power in F if, and only if, it is an m-th power in Fv for each place v of F . For instance, if m 6≡ 0 mod 8, or if F = Q, then (F,m) is not special.
The Promotion Club

How can principals in an organization incentivize efforts while maintaining personnel flexibility? We show that a "promotion club" solves a large part of the problem: Principal selects, from n agents, m top-performing agents into a club, and then promote one from within a club based fully on principal's idiosyncratic preference ("mindset"). Intuitively, m=1 indicates a tournament, and m=n, cronyism. We show that a proper (m>1) promotion club outperforms tournament in efforts when the homogenous agents are many. Under heterogeneous agents, it may still outperform tournament due to intra-crony competition. We use promotion data of Chinese governments at different levels to validate the model and test its predictions. Our theory and empirical evidence helps to explain how an organization with centralized personnel control manages to incentivize subordinates while maintaining high degrees of discretionary power at the top. JEL: P16 M50 D73 H11 1 Shuo Chen, Department of Economics, Fudan University, mail: cs@fudan.edu. cn; Xinyu Fan: Cheung Kong Graduate School of Business, mail: xyfan@ckgsb.edu. cn; Zhitao Zhu: Department of Economics, Chise University of Hong Kong, mail: zhuzhitao@link.cuhk. edu.hk. We thank Xi Weng, Zenan Wu, Zhuoran Lu, Zhiyong Yao, Kyle Woodward, Yang Xie, seminar participants in Peking University, Fudan University, Shantou University, Econometric Society Asian Meeting at Xiamen, for their useful comments and suggestions on previous drafts. This work was supported by the National Natural Science Foundation of China (71303059) and Innovation Program of Shanghai Municipal Education Commission (2017-01-07-00-07-E00002). All remaining errors are our own.
Creditor Rights, Debt Capacity and Securities Issuance: Evidence from Anti-Recharacterization Laws

This paper examines the effects of improvement in creditors’ rights protection on firms’ financing choices and securities issuance. To address these issues, I exploit exogenous variation in creditors’ rights protection induced by the staggered adoption of anti-recharacterization laws by some U.S. states. The laws enhance the ability of creditors to repossess collateral during bankruptcy. Using a difference-in-difference methodology to estimate the causal impacts, I find that: [1] the laws are positively related to debt capacity and debt maturity. Firms increase market leverage and substitute away from costly short-term debt financing into long-term debt financing [2] the laws are positively related to debt issuance [3] the laws are negatively related to equity issuance. My analysis further demonstrates that proactive securities issuers are significantly more responsive to the adoption of anti-recharacterization laws than passive securities issuers
Successional trends in Sonoran Desert abandoned agricultural fields in northern Mexico

Excessive ground-water use and saline intrusion to the aquifer led, in less than three decades, to an increase in abandoned agricultural fields at La Costa de Hermosillo, within the Sonoran Desert. Using a chronosequence from years since abandonment, patterns of field succession were developed. Contrary to most desert literature, species replacement was found, both in fields with and without saline intrusion. Seasonal photosynthetic capacity as well as water and nitrogen use efficiencies were different in dominant early and late successional plant species. These ecological findings provided a framework for a general explanation of species dominance and replacement within abandoned agricultural fields in the Sonoran Desert. r 2004 Elsevier Ltd. All rights reserved.
Large Scale FM Signal Strength Map Estimation For Passive Approximate Localization

In this paper, we present a coarse, passive localization system for GPS denied environments. Our system is based on broadcast FM radio signals and uses RSSI obtained using an inexpensive software defined radio (SDR). The RSSI thus obtained is used for matching into a large database of estimated FM spectrum for the entire United States. We show that with an inexpensive hardware for data acquisition and associated algorithms, we are capable of localizations that can be used for countering GPS spoofing. The algorithm is based on a large-scale pre-processing phase that estimates the probable FM power spectrum in small rectangular cells (realized using geohashes) across entire US, from various FM towers in the locality. The query phase first runs a peak detector on the power spectrum obtained using the SDR and then solves a subset query problem to compute proposed locations (geohashes) to be analyzed. Finally, it uses a simple Euclidean nearest neighbor search to localize the observed power spectrum to a location of interest. We use more than nine hundred observed power spectra distributed over four hundred miles in Florida for experimentally validating our query algorithm. We also provide a Bayesian decision theoretic explanation for the nearest neighbor search.
Minorities and Business: the Case of Russian Old Believers⇤

In 19th century Russia, a close-knit and persecuted religious minority, the Old Believers, controlled a large share of textile manufacturing. I estimate the production functions of the textile factories of Moscow province (the main center of Old Believers’ business) in 1882–1883, using their share in the population within a 7 km range from the factory as a proxy for the status of Old Believers’ factory. The Old Believers’ factories had a higher Total Factor Productivity, but this effect is only observed in the districts that generally had a high share of Old Believers. I interpret this as evidence of the social capital theory of this minority’s economic prominence, indicating the importance of business networks that developed in the Old Believers’ communes. Following the existing literature on the role of Protestants in the economic development of Europe, I also control for human capital and geography factors and do not find that they explain the business success of Old Believers. ⇤I would like to thank Steven Nafziger from Williams College for the data he provided and the suggestions he made, and Simeon Djankov, Paul Dower and Andrei Markevich, my advisors at NES, for their guidance and support I received from them. I would also like to thank Amanda Gregg from Middlebury College for her comments to the early version of this paper. All errors are my own.
Electromagnetic Precursors to Gravitational-wave Events: Numerical Simulations of Flaring in Pre-merger Binary Neutron Star Magnetospheres

The detection of gravitational waves from neutron star merger events has opened up a new field of multimessenger astronomy linking gravitational-wave events to short gamma-ray bursts and kilonova afterglows. A further—yet to be discovered—electromagnetic counterpart is a precursor emission produced by the nontrivial interaction of the magnetospheres of the two neutron stars prior to merger. By performing special-relativistic force-free simulations of orbiting neutron stars we discuss the effect of different magnetic field orientations and show how the emission can be significantly enhanced by differential motion present in the binary, either due to stellar spins or misaligned stellar magnetospheres. We find that the buildup of twist in the magnetic flux tube connecting the two stars can lead to the repeated emission of powerful flares for a variety of orbital configurations. We also discuss potential coherent radio emission mechanisms in the flaring process.
Securing Wireless Sensor Networks Against Denial‐of‐Sleep Attacks Using RSA Cryptography Algorithm and Interlock Protocol

Wireless sensor networks (WSNs) have been vastly employed in the collection and transmission of data via wireless networks. This type of network is nowadays used in many applications for surveillance activities in various environments due to its low cost and easy communications. In these networks, the sensors use a limited power source which after its depletion, since it is non‐renewable, network lifetime ends. Due to the weaknesses in sensor nodes, they are vulnerable to many threats. One notable attack threating WSN is Denial of Sleep (DoS). DoS attacks denotes the loss of energy in these sensors by keeping the nodes from going into sleep and energy‐saving mode. In this paper, the Abnormal Sensor Detection Accuracy (ASDA‐RSA) method is utilized to counteract DoS attacks to reducing the amount of energy consumed. The ASDA‐RSA schema in this paper consists of two phases to enhancement security in the WSNs. In the first phase, a clustering approach based on energy and distance is used to select the proper cluster head and in the second phase, the RSA cryptography algorithm and interlock protocol are used here along with an authentication method, to prevent DoS attacks. Moreover, ASDA‐RSA method is evaluated here via extensive simulations carried out in NS‐2. The simulation results indicate that the WSN network performance metrics are improved in terms of average throughput, Packet Delivery Ratio (PDR), network lifetime, detection ratio, and average residual energy.
Rumor Detection on Social Media with Bi-Directional Graph Convolutional Networks

Social media has been developing rapidly in public due to its nature of spreading new information, which leads to rumors being circulated. Meanwhile, detecting rumors from such massive information in social media is becoming an arduous challenge. Therefore, some deep learning methods are applied to discover rumors through the way they spread, such as Recursive Neural Network (RvNN) and so on. However, these deep learning methods only take into account the patterns of deep propagation but ignore the structures of wide dispersion in rumor detection. Actually, propagation and dispersion are two crucial characteristics of rumors. In this paper, we propose a novel bi-directional graph model, named Bi-Directional Graph Convolutional Networks (Bi-GCN), to explore both characteristics by operating on both top-down and bottom-up propagation of rumors. It leverages a GCN with a top-down directed graph of rumor spreading to learn the patterns of rumor propagation; and a GCN with an opposite directed graph of rumor diffusion to capture the structures of rumor dispersion. Moreover, the information from source post is involved in each layer of GCN to enhance the influences from the roots of rumors. Encouraging empirical results on several benchmarks confirm the superiority of the proposed method over the state-of-the-art approaches.
Dysphagia in unilateral medullary infarction: Lateral vs medial lesions

Objective:To study dysphagia in pure,unilateral medullary infarction using video fluoroscopic swallowing (VFS) tests and to compare the results between lateral medullary infarction (LMI)-and medial medullary infarction (MMI). Methods: We studied 46 patients with medullary infarction (37 LMI, 9 MMI). Based on the MRI findings, each LMI was classified rostrocaudally as either a rostral or caudal lesion, and horizontally as either a superficial (lateral +dorsal) or nonsuperficial lesion. Each MMI was assigned to either a deep (lesion extending to the dorsal surface) or superficial lesion group. VFS examination was conducted and an 8-point scale was used for assessing the severity of dysphagia. Based on these results, dysphagia was classified as: 1) problems on timing of hyolaryngeal excursion (PT), and 2) problems on range of hyolaryngeal excursion (PR). Results: Dysphagia was more frequent (p 0.05) in MMI patients (78%) than in LMI patients (35%). Among the LMI patients, dysphagia was more frequent (p 0.01) and severe (p 0.01) in the rostral than in the cadual group and in the nonsuperficial than in the superficial group. In the MMI group, there was no difference in the frequency of dysphagia between the deep and superficial groups. Regarding the characteristics of dysphagia, seven (54%) of the LMI patients had PR, five (38%) had PT, and one (8%) had both. For the MMI patients, PT was frequent (86%) but PR was present in only one patient (14%). Five MMI patients (71%) showed no responses to penetration or aspiration, and silent dysphagia was observed in only four LMI patients (31%). Conclusions: Dysphagia is as frequent and severe in medial medullary infarction (MMI) as in lateral medullary infarction (LMI) patients. The types and characteristics of dysphagia are different between the LMI and MMI patients, implicating the rationale for a different treatment strategy.
A Submillimeter Perspective on the GOODS Fields (SUPER GOODS). IV. The Submillimeter Properties of X-Ray Sources in the CDF-S

The Chandra Deep Field (CDF)-S is the deepest X-ray image available and will remain so for the near future. We provide a spectroscopic (64.5%; 64% with spectral classifications) and photometric redshift catalog for the full 7 Ms sample, but much of our analysis focuses on the central (off-axis angles <5.′7) region, which contains a large, faint ALMA sample of 75 > 4. 5σ 850 μm sources. We measure the 850 μm fluxes at the X-ray positions using the ALMA images, where available, or an ultradeep SCUBA-2 map. We find that the full X-ray sample produces ∼10% of the 850 μm extragalactic background light. We separate the submillimeter-detected X-ray sources into star-forming galaxies and active galactic nuclei (AGNs) using a star formation rate (SFR) versus X-ray luminosity calibration for high-SFR galaxies. We confirm this separation using the X-ray photon indices. We measure the X-ray fluxes at the accurate positions of the 75 ALMA sources and detect 70% at >3σ in either the 0.5–2 or 2–7 keV bands. However, many of these may produce both their X-ray and submillimeter emission by star formation. Indeed, we find that only 20% of the ALMA sources have intermediate X-ray luminosities (rest-frame 8–28 keV luminosities of 1042.5–1044 erg s−1), and none has a high X-ray luminosity (>1044 erg s−1). Conversely, after combining the CDF-S with the CDF-N, we find extreme star formation (SFR > 300 M⊙ yr−1) in some intermediate X-ray luminosity sources but not in any high X-ray luminosity sources. We argue that the quenching of star formation in the most luminous AGNs may be a consequence of the clearing of gas in these sources.
Parker Solar Probe In Situ Observations of Magnetic Reconnection Exhausts during Encounter 1

Magnetic reconnection in current sheets converts magnetic energy into particle energy. The process may play an important role in the acceleration and heating of the solar wind close to the Sun. Observations from Parker Solar Probe (PSP) provide a new opportunity to study this problem, as it measures the solar wind at unprecedented close distances to the Sun. During the first orbit, PSP encountered a large number of current sheets in the solar wind through perihelion at 35.7 solar radii. We performed a comprehensive survey of these current sheets and found evidence for 21 reconnection exhausts. These exhausts were observed in heliospheric current sheets, coronal mass ejections, and regular solar wind. However, we find that the majority of current sheets encountered around perihelion, where the magnetic field was strongest and plasma β was lowest, were Alfvénic structures associated with bursty radial jets, and these current sheets did not appear to be undergoing local reconnection. We examined conditions around current sheets to address why some current sheets reconnected while others did not. A key difference appears to be the degree of plasma velocity shear across the current sheets: the median velocity shear for the 21 reconnection exhausts was 24% of the Alfvén velocity shear, whereas the median shear across 43 Alfvénic current sheets examined was 71% of the Alfvén velocity shear. This finding could suggest that large, albeit sub-Alfvénic, velocity shears suppress reconnection. An alternative interpretation is that the Alfvénic current sheets are isolated rotational discontinuities that do not undergo local reconnection.
On the Emergence Mechanism of Carrot Sprites

We investigate the launch of negative upward streamers from sprite glows. This phenomenon is readily observed in high‐speed observations of sprites and underlies the classification of sprites into carrot or column types. First, we describe how an attachment instability leads to a sharply defined region in the upper part of the streamer channel. This region has an enhanced electric field, low conductivity and strongly emits in the first positive system of molecular nitrogen. We identify it as the sprite glow. We then show how, in the most common configuration of a carrot sprite, several upward streamers emerge close to the lower boundary of the glow, where negative charge gets trapped and the lateral electric field is high enough. These streamers cut off the current flowing toward the glow and lead to the optical deactivation of the glow above. Finally, we discuss how our results naturally explain angel sprites.
ArguLens: Anatomy of Community Opinions On Usability Issues Using Argumentation Models

In open-source software (OSS), the design of usability is often influenced by the discussions among community members on platforms such as issue tracking systems (ITSs). However, digesting the rich information embedded in issue discussions can be a major challenge due to the vast number and diversity of the comments. We propose and evaluate ArguLens, a conceptual framework and automated technique leveraging an argumentation model to support effective understanding and consolidation of community opinions in ITSs. Through content analysis, we anatomized highly discussed usability issues from a large, active OSS project, into their argumentation components and standpoints. We then experimented with supervised machine learning techniques for automated argument extraction. Finally, through a study with experienced ITS users, we show that the information provided by ArguLens supported the digestion of usability-related opinions and facilitated the review of lengthy issues. ArguLens provides the direction of designing valuable tools for high-level reasoning and effective discussion about usability.
Entropies and the first laws of black hole thermodynamics in Einstein-aether-Maxwell theory

Using the solution phase space method, we investigate the thermodynamics of black holes in Einstein-aether-Maxwell theory, for which the traditional Wald method (covariant phase space method) fails. We show the first laws of thermodynamics and definitive entropy expressions at both Killing and universal horizons for some examples of exact black hole solutions, including three-dimensional static charged quasi-BTZ black hole, two four-dimensional static charged black holes and three-dimensional rotating solution. At Killing horizons the entropies are exactly one quarter of the horizon area, but at universal horizons of three-dimensional black holes, the entropies have a corrected term in addition to the one proportional to the horizon area.
SNODE: Spectral Discretization of Neural ODEs for System Identification

This paper proposes the use of spectral element methods \citep{canuto_spectral_1988} for fast and accurate training of Neural Ordinary Differential Equations (ODE-Nets; \citealp{Chen2018NeuralOD}) for system identification. This is achieved by expressing their dynamics as a truncated series of Legendre polynomials. The series coefficients, as well as the network weights, are computed by minimizing the weighted sum of the loss function and the violation of the ODE-Net dynamics. The problem is solved by coordinate descent that alternately minimizes, with respect to the coefficients and the weights, two unconstrained sub-problems using standard backpropagation and gradient methods. The resulting optimization scheme is fully time-parallel and results in a low memory footprint. Experimental comparison to standard methods, such as backpropagation through explicit solvers and the adjoint technique \citep{Chen2018NeuralOD}, on training surrogate models of small and medium-scale dynamical systems shows that it is at least one order of magnitude faster at reaching a comparable value of the loss function. The corresponding testing MSE is one order of magnitude smaller as well, suggesting generalization capabilities increase.
Distinguishing simple groups.

The distinguishing number $D(\Gamma)$ of a graph $\Gamma$ is the least size of a partition of the vertices of $\Gamma$ such that no non-trivial automorphism of $\Gamma$ preserves this partition. We show that if the automorphism group of a graph $\Gamma$ is simple, than $D(\Gamma)=2$. This is obtained by establishing the distinguishing number for all possible actions of simple groups.
The accretion rates and mechanisms of Herbig Ae/Be stars

This work presents a spectroscopic study of 163 Herbig Ae/Be stars. Amongst these, we present new data for 30 objects. Stellar parameters such as temperature, reddening, mass, luminosity, and age are homogeneously determined. Mass accretion rates are determined from $\rm H\alpha$ emission line measurements. Our data is complemented with the X-Shooter sample from previous studies and we update results using Gaia DR2 parallaxes giving a total of 78 objects with homogeneously determined stellar parameters and mass accretion rates. In addition, mass accretion rates of an additional 85 HAeBes are determined. We confirm previous findings that the mass accretion rate increases as a function of stellar mass, and the existence of a different slope for lower and higher mass stars, respectively. The mass where the slope changes is determined tobe $3.98^{+1.37}_{-0.94}\, \rm M_{\odot }$. We discuss this break in the context of different modes of disc accretion for low- and high-mass stars. Because of their similarities with T Tauri stars, we identify the accretion mechanism for the late-type Herbig stars with the Magnetospheric Accretion. The possibilities for the earlier-type stars are still open, we suggest the Boundary Layer accretion model may be a viable alternative. Finally, we investigated themass accretion–age relationship. Even using the superior Gaia based data, it proved hard to select a large enough sub-sample to remove the mass dependence in this relationship. Yet, it would appear that the mass accretion does decline with age as expected from basic theoretical considerations.