cssi/SciSciGPT-SciSciNet huggingface dataset:
Refining After-Tax Return and Risk Parameters

Taxes introduce certain complexities, requiring proper adjustments to return and risk parameters. The author offers a refined set of after-tax return and risk equations for use in practice and validates them with a stochastic future value cash flow model. The refined after-tax return and risk parameters can be used in portfolio optimization, Monte Carlo simulation, and deterministic present/future value portfolio modeling with internally consistent results. The refinements improve the discovery of the optimal after-tax portfolio and enhance long-term wealth planning in the presence of risk. TOPIC:Wealth management Key Findings • After-tax return and risk parameters are necessary for efficient asset allocation and accurate wealth planning. • Parameters must incorporate tax complexity while producing internally consistent results across portfolio optimization, Monte Carlo simulation, and deterministic modeling. • Refinements include the arithmetic-geometric return treatment with tax, a more precise incorporation of the effective annual capital gains tax rate, and risk manifesting in the price return across the distribution.
A Structuralist Concept of the Rule of Law

The prevalent approach to the concept of the rule of law among legal theorists puts attributes first, assigning certain features of laws and sometimes legal systems as rule-of-law virtues. Inquiring at a more basic level, this paper advances a novel, structuralist view of the rule of law. While honoring theoretical constraints that guard against diluting the rule-of-law concept too thinly as a remedy for myriad societal ills, this approach shows that the concept implicates inequalities sustained by a society’s social, economic, and political structures. This is accomplished by demonstrating that the rule-of-law project holds a structural position in the collective normative discourse as a vehicle by which people morally evaluate the interplay between the actual capabilities of individuals and groups to participate in law, and the legal system’s treatment of those individuals and groups. Law’s procedural outputs may formally provide the public with access to the legal system, but the rule-of-law project goes to the actual capabilities of the people to access the system in reality, to have a fair opportunity to participate in the inputs into the system, and to have that participation impartially adjudicated. Conditions impacting a diversity of stakeholders – and particularly the most disadvantaged within the population – perturb the virtues typically associated with the rule-of-law ideal when those conditions, and the power exercised to maintain them, impair capabilities for fair, dignified, and equal access to legal processes. Understanding the rule of law in structuralist terms, as an informal moral operator, (1) makes sense of the schism we normally accept between the concepts of law and the rule of law, (2) reorients the source of rule-of-law thinking from theorists bent on fixing a conceptual definition to communities engaged in first-order interactions with the legal system, (3) helps explain why citizens come not only to expect law to constrain official coercive powers but also to demand that law promote their actual capabilities to participate in the legal system on an egalitarian and dignitarian footing, and hence (4) implicates a critique of conditions of political and material inequalities that cannot but impair the healthy functioning of the rule-of-law project.
SeeMoRe: A Fault-Tolerant Protocol for Hybrid Cloud Environments

Large scale data management systems utilize State Machine Replication to provide fault tolerance and to enhance performance. Fault-tolerant protocols are extensively used in the distributed database infrastructure of large enterprises such as Google, Amazon, and Facebook. However, and in spite of years of intensive research, existing fault-tolerant protocols do not adequately address hybrid cloud environments consisting of private and public clouds which are widely used by enterprises. In this paper, we consider a private cloud consisting of nonmalicious nodes (crash-only failures) and a public cloud with possible malicious failures. We introduce SeeMoRe, a hybrid State Machine Replication protocol that uses the knowledge of where crash and malicious failures may occur in a public/private cloud environment to improve overall performance. SeeMoRe has three different modes that can be used depending on the private cloud load and the communication latency between the public and private clouds. SeeMoRe can dynamically transition from one mode to another. Furthermore, an extensive evaluation reveals that SeeMoRe’s performance is close to the state of the art crash fault-tolerant protocols while tolerating malicious failures.
A Practical Spectrum Sharing Scheme for Cognitive Radio Networks: Design and Experiments

Spectrum shortage is a fundamental problem in wireless networks, and this problem becomes increasingly acute with the rapid proliferation of wireless devices. To address this issue, spectrum sharing in the context of cognitive radio networks (CRNs) has been regarded as a promising solution. Although there is a large body of work on spectrum sharing in the literature, most existing work is limited to theoretical exploration and the progress in practical solution design remains scarce. In this paper, we propose a practical scheme to enable transparent spectrum sharing for a small CRN by leveraging recent advances in multiple-input multiple-output (MIMO) technology. The key components of our scheme are two MIMO-based interference management techniques: blind beamforming (BBF) and blind interference cancellation (BIC). These two techniques enable secondary users to mitigate cross-network interference in the absence of inter-network coordination, fine-grained synchronization, and mutual knowledge. We have built a prototype of our scheme on a wireless testbed and demonstrated its compatibility with commercial Wi-Fi devices (primary users). Experimental results show that, for a secondary device with two/three antennas, BBF and BIC achieve an average of 25 dB and 33 dB interference cancellation capabilities in real-world wireless environments, respectively.
Masked Language Model Scoring

Pretrained masked language models (MLMs) require finetuning for most NLP tasks. Instead, we evaluate MLMs out of the box via their pseudo-log-likelihood scores (PLLs), which are computed by masking tokens one by one. We show that PLLs outperform scores from autoregressive language models like GPT-2 in a variety of tasks. By rescoring ASR and NMT hypotheses, RoBERTa reduces an end-to-end LibriSpeech model’s WER by 30% relative and adds up to +1.7 BLEU on state-of-the-art baselines for low-resource translation pairs, with further gains from domain adaptation. We attribute this success to PLL’s unsupervised expression of linguistic acceptability without a left-to-right bias, greatly improving on scores from GPT-2 (+10 points on island effects, NPI licensing in BLiMP). One can finetune MLMs to give scores without masking, enabling computation in a single inference pass. In all, PLLs and their associated pseudo-perplexities (PPPLs) enable plug-and-play use of the growing number of pretrained MLMs; e.g., we use a single cross-lingual model to rescore translations in multiple languages. We release our library for language model scoring at https://github.com/awslabs/mlm-scoring.
Latent Feature Extraction for Process Data via Multidimensional Scaling

Computer-based interactive items have become prevalent in recent educational assessments. In such items, detailed human–computer interactive process, known as response process, is recorded in a log file. The recorded response processes provide great opportunities to understand individuals’ problem solving processes. However, difficulties exist in analyzing these data as they are high-dimensional sequences in a nonstandard format. This paper aims at extracting useful information from response processes. In particular, we consider an exploratory analysis that extracts latent variables from process data through a multidimensional scaling framework. A dissimilarity measure is described to quantify the discrepancy between two response processes. The proposed method is applied to both simulated data and real process data from 14 PSTRE items in PIAAC 2012. A prediction procedure is used to examine the information contained in the extracted latent variables. We find that the extracted latent variables preserve a substantial amount of information in the process and have reasonable interpretability. We also empirically prove that process data contains more information than classic binary item responses in terms of out-of-sample prediction of many variables.
Improvement of Osteoporosis Screening among Inflammatory Bowel Disease Patients at Gastroenterology Fellows’ Clinics

Introduction. Individuals with inflammatory bowel disease (IBD) have an increased risk of osteoporosis compared to the general population. We aimed to improve the osteoporosis screening rate in the IBD patient population of the gastroenterology (GI) fellows’ continuity clinics. Methods. Baseline preintervention data were collected on patients seen from July through September of 2018. Four simplified criteria for osteoporosis screening were extrapolated from 3 national guidelines. Among patients who met any of these criteria, we determined the baseline screening rate. Fellows were then educated with a didactic session and handout material, and a standardized template was incorporated into clinic notes. Following this intervention, screening rates were reassessed from December 2018 through February 2019. Results. During the preintervention phase, fellows saw 80 patients with IBD. Dual-energy X-ray absorptiometry (DEXA) scan was obtained in 44% of IBD patients who qualify for screening at the county hospital clinic compared to 21% of veterans’ clinic IBD patients. In the postintervention period, screening rates remarkably improved to 100% in the county hospital clinic and to 75% in the veterans’ clinic. Overall, the screening rate increased by 56% ( ). Conclusions. A large percentage of IBD patients at risk for osteoporosis did not have appropriate bone mass density testing. Educating GI fellows and adding a template to clinic notes were effective in significantly improving the number of patients at risk of osteoporosis to receive appropriate screening test, a DEXA scan. Similar educational interventions should be considered for providers caring for IBD patients to prevent complications of osteoporosis in these patients.
Online Non-Convex Learning: Following the Perturbed Leader is Optimal

We study the problem of online learning with non-convex losses, where the learner has access to an offline optimization oracle. We show that the classical Follow the Perturbed Leader (FTPL) algorithm achieves optimal regret rate of $O(T^{-1/2})$ in this setting. This improves upon the previous best-known regret rate of $O(T^{-1/3})$ for FTPL. We further show that an optimistic variant of FTPL achieves better regret bounds when the sequence of losses encountered by the learner is `predictable'.
Matching queues with reneging: a product form solution

Motivated by growing applications in two-sided markets, we study a parallel matching queue with reneging. Demand and supply units arrive to the system and are matched in an FCFS manner according to a compatibility graph specified by an N-system. If they cannot be matched upon arrival, they queue and may abandon the system as time goes by. We derive explicit product forms of the steady-state distributions of this system by identifying a partial balance condition.
Risk Aversion, Offsetting Community Effects, and COVID-19: Evidence from an Indoor Political Rally

The Centers for Disease Control and Prevention (CDC) deem large indoor gatherings without social distancing the “highest risk” activity for COVID-19 contagion. On June 20, 2020, President Donald J. Trump held his first mass campaign rally following the US coronavirus outbreak at the indoor Bank of Oklahoma arena. In the weeks following the event, numerous high-profile national news outlets reported that the Trump rally was “more than likely” the cause of a coronavirus surge in Tulsa County based on time series data. This study is the first to rigorously explore the impacts of this event on social distancing and COVID-19 spread. First, using data from SafeGraph Inc, we show that while non-resident visits to census block groups hosting the Trump event grew by approximately 25 percent, there was no decline in net stay-at-home behavior in Tulsa County, reflecting important offsetting behavioral effects. Then, using data on COVID-19 cases from the CDC and a synthetic control design, we find little evidence that COVID-19 grew more rapidly in Tulsa County, its border counties, or in the state of Oklahoma than each’s estimated counterfactual during the five-week post-treatment period we observe. Difference-in-differences estimates further provide no evidence that COVID-19 rates grew faster in counties that drew relatively larger shares of residents to the event. We conclude that offsetting risk-related behavioral responses to the rally—including voluntary closures of restaurants and bars in downtown Tulsa, increases in stay-at-home behavior, displacement of usual activities of weekend inflows, and smaller-than-expected crowd attendance—may be important mechanisms.
Minimum-fuel aeroassisted coplanar orbit transfer using lift-modulation

Minimum-fuel trajectories and lift controls are computed for aeroassisted coplanar transfer from high orbit to low orbit. The optimal aeroassisted transfer requires less fuel than the all-propulsive Hohmann transfer for a wide range of high orbit to low orbit transfers. The optimal control program for the atmospheric portion of the transfer is to fly at maximum positive L/D initially to recover from the downward plunge, and then, to fly at negative L/D to level off the flight, such that the vehicle skips out of the atmosphere with a flight path angle near zero degrees. To avoid excessive heating rates, the vehicle flies initially at high angle of attack in order to slow down higher in the atmosphere, allowing recovery from the downward plunge, which occurs subsequently using the maximum positive L/D, to take place at a lower atmospheric density, or equivalently, at a higher altitude.
Exploratory study of young children's social media needs and requirements

As social media are becoming increasingly popular among young children, it is important to explore this population's needs and requirements from these platforms. As a first step to this, we conducted an exploratory design workshop with children aged between ten and eleven years to find out about their social media needs and requirements. Through an analysis of the paper prototypes solicited from the workshop, here we discuss the social media features that are the most desired by this population.
Investment effects of pricing schemes for non-convex markets

Abstract Non-convex markets, such as those organized by electricity system operators, lack uniform clearing prices. In an attempt to align private and social costs when clearing these markets, operators have introduced a variety of price formation and uplift payment schemes. We investigate the impact that the choice of pricing scheme can have on generator entry and exit decisions. Our results suggest that despite the presence of fixed production cost elements, prices derived from marginal costs support the optimal capacity mix. The use of uplift payments to supplement these prices could lead to significant distortion of the capacity mix arising in competitive markets. Pricing schemes designed to reduce the need for uplift payments may at the same time reduce prices, leading to lower levels of capacity in equilibrium. Schemes intended to raise prices, to the extent they eliminate the need for discriminatory side payments, may allow system operators to support a higher level of capacity with less distortion to the capacity mix.
Keeping the Barbarians at the Gates: The Promise of the UNESCO and UNIDROIT Conventions for Developing Countries

The illicit trade in cultural property is a global phenomenon, powered by criminal networks and smuggling trains that sacrifice local culture for the black market of the art world. Headlines featuring the Islamic State’s lucrative exchange in stolen cultural property, among other incidents, have raised the profile of the illicit cultural property trade on the global stage. Developing countries, as the most prominent source countries of cultural property, are particularly at risk. Existing scholarship has searched for a solution to this crisis, suggesting a new international treaty to protect cultural property or recommending the utilization of adjacent legal fields. However, these solutions overlook the ready benefits of two existing international treaties on cultural property, the United Nations Educational, Scientific and Cultural Organization (“UNESCO”) and United Nations International Institute for the Unification of Private Law (“UNIDROIT”) Conventions. While the UNESCO and UNIDROIT Conventions do not provide an absolute solution to the illicit cultural property trade, they are accessible and underutilized options that are particularly calibrated to assist developing countries. Increased ratification of the UNESCO and UNIDROIT Conventions would grant source country States Parties the enforcement benefits of the import regulations and domestic court systems of market country States Parties, and the strength of the Conventions would rise as the number of signatories increases. The costs imposed on developing country signatories are deliberately low to aid them in protection and recovery. Furthermore, the adoption of these two Conventions does not constrain States Parties from contemplating and implementing additional mechanisms to further protect cultural property. The UNESCO and UNIDROIT Conventions thus offer ready, underutilized options for developing countries to better protect their cultural property.
An R Package for Generating Covariance Matrices for Maximum-Entropy Sampling from Precipitation Chemistry Data

We present an open-source R package (MESgenCov v 0.1.0) for temporally fitting multivariate precipitation chemistry data and extracting a covariance matrix for use in the MESP (maximum-entropy sampling problem). We provide multiple functionalities for modeling and model assessment. The package is tightly coupled with NADP/NTN (National Atmospheric Deposition Program/National Trends Network) data from their set of 379 monitoring sites, 1978–present. The user specifies the sites, chemicals, and time period desired, fits an appropriate user-specified univariate model for each site and chemical selected, and the package produces a covariance matrix for use by MESP algorithms.
Mission-Aware Spatio-Temporal Deep Learning Model for UAS Instantaneous Density Prediction

The number of daily sUAS operations in uncontrolled low altitude airspace is expected to reach into the millions in a few years. Therefore, UAS density prediction has become an emerging and challenging problem. In this paper, a deep learning-based UAS instantaneous density prediction model is presented. The model takes two types of data as input: 1) the historical density generated from the historical data, and 2) the future sUAS mission information. The architecture of our model contains four components: Historical Density Formulation module, UAS Mission Translation module, Mission Feature Extraction module, and Density Map Projection module. The training and testing data are generated by a python based simulator which is inspired by the multi-agent air traffic resource usage simulator (MATRUS) framework. The quality of prediction is measured by the correlation score and the Area Under the Receiver Operating Characteristics (AUROC) between the predicted value and simulated value. The experimental results demonstrate outstanding performance of the deep learning-based UAS density predictor. Compared to the baseline models, for simplified traffic scenario where no-fly zones and safe distance among sUASs are not considered, our model improves the prediction accuracy by up to 15.2% and its correlation score reaches 0.947. In a more realistic scenario, where the no-fly zone avoidance and the safe distance among sUASs are maintained using A* routing algorithm, our model can still achieve 0.822 correlation score. Meanwhile, the AUROC can reach 0.951 for the hot spot prediction.
Miniaturized Circuitry for Capacitive Self-Sensing and Closed-Loop Control of Soft Electrostatic Transducers.

Soft robotics is a field of robotic system design characterized by materials and structures that exhibit large-scale deformation, high compliance, and rich multifunctionality. The incorporation of ...
Strata of a disconnected reductive group

Abstract Let D be a fixed connected component of a reductive algebraic group over an algebraically closed field. We use a variant of the Springer representation to define and study a partition of D into finitely many Strata, one of which is the open set of regular elements. We show that the Strata of D are indexed by a set defined purely in terms of the Weyl group and its automorphism defined by D .
Analysis of KSHV B lymphocyte lineage tropism in human tonsil reveals efficient infection of CD138+ plasma cells.

Despite 25 years of research, the basic virology of Kaposi Sarcoma Herpesviruses (KSHV) in B lymphocytes remains poorly understood. This study seeks to fill critical gaps in our understanding by characterizing the B lymphocyte lineage-specific tropism of KSHV. Here, we use lymphocytes derived from 40 human tonsil specimens to determine the B lymphocyte lineages targeted by KSHV early during de novo infection in our ex vivo model system. We characterize the immunological diversity of our tonsil specimens and determine that overall susceptibility of tonsil lymphocytes to KSHV infection varies substantially between donors. We demonstrate that a variety of B lymphocyte subtypes are susceptible to KSHV infection and identify CD138+ plasma cells as a highly targeted cell type for de novo KSHV infection. We determine that infection of tonsil B cell lineages is primarily latent with few lineages contributing to lytic replication. We explore the use of CD138 and heparin sulfate proteoglycans as attachment factors for the infection of B lymphocytes and conclude that they do not play a substantial role. Finally, we determine that the host T cell microenvironment influences the course of de novo infection in B lymphocytes. These results improve our understanding of KSHV transmission and the biology of early KSHV infection in a naive human host, and lay a foundation for further characterization of KSHV molecular virology in B lymphocyte lineages.
Using rat operant delayed match-to-sample task to identify neural substrates recruited with increased working memory load

The delayed match-to-sample task (DMS) is used to probe working memory (WM) across species. While the involvement of the PFC in this task has been established, limited information exists regarding the recruitment of broader circuitry, especially under the low- versus high-WM load. We sought to address this question by using a variable-delay operant DMS task. Male Sprague-Dawley rats were trained and tested to determine their baseline WM performance across all (0- to 24-sec) delays. Next, rats were tested in a single DMS test with either 0- or 24-sec fixed delay, to assess low-/high-load WM performance. c-Fos mRNA expression was quantified within cortical and subcortical regions and correlated with WM performance. High WM load up-regulated overall c-Fos mRNA expression within the PrL, as well as within a subset of mGlu5+ cells, with load-dependent, local activation of protein kinase C (PKC) as the proposed underlying molecular mechanism. The PrL activity negatively correlated with choice accuracy during high load WM performance. A broader circuitry, including several subcortical regions, was found to be activated under low and/or high load conditions. These findings highlight the role of mGlu5- and/or PKC-dependent signaling within the PrL, and corresponding recruitment of subcortical regions during high-load WM performance.
Regression Oracles and Exploration Strategies for Short-Horizon Multi-Armed Bandits

This paper explores multi-armed bandit (MAB) strategies in very short horizon scenarios, i.e., when the bandit strategy is only allowed very few interactions with the environment. This is an understudied setting in the MAB literature with many applications in the context of games, such as player modeling. Specifically, we pursue three different ideas. First, we explore the use of regression oracles, which replace the simple average used in strategies such as ϵ-greedy with linear regression models. Second, we examine different exploration patterns such as forced exploration phases. Finally, we introduce a new variant of the UCB1 strategy called UCBT that has interesting properties and no tunable parameters. We present experimental results in a domain motivated by exergames, where the goal is to maximize a player’s daily steps. Our results show that the combination of ϵ-greedy or ϵ-decreasing with regression oracles outperforms all other tested strategies in the short horizon setting.
Lamplighters admit weakly aperiodic SFTs

Let $A$ be a finite set and $G$ a group. A closed subset $X$ of $A^G$ is called a subshift if the action of $G$ on $A^G$ preserves $X$. If $K$ is a closed subset of $A^G$ such that membership in $K$ is determined by looking at a fixed finite set of coordinates, and $X$ is the intersection of all translates of $K$ under the action of $G$, then $X$ is called a subshift of finite type (SFT). If an SFT is nonempty and contains no finite $G$-orbits, it is said to be weakly aperiodic. A virtually cyclic group has no weakly aperiodic SFT, and Carroll and Penland have conjectured that a group with no weakly aperiodic SFT must be virtually cyclic. Answering a question of Jeandel, we show that lamplighters always admit weakly aperiodic SFTs.
Structural Breaks in an Endogenous Growth Model

We study the effects of parameter uncertainty prompted by structural breaks. In our model, agents respond differently to uncertainty prompted by regime shifts in shock processes than they react to comparable perceived increases in shock volatility. The magnitude of the response to an increase in uncertainty about TFP associated with a structural break is greater than that of a response to a comparable perceived rise in volatility. This is because lifetime utility varies more when shocks shift beliefs and perceived wealth.
Aging and the perception of motion-defined form

A single experiment required 26 younger and older adults to discriminate global shape as defined only by differences in the speed of stimulus element rotation. Detection of the target shape require...
The Ramanujan sum and Chebotarev densities

In this short note, we show an analogue of one of Alladi’s and Dawsey’s formulas with respect to the Ramanujan sum $$c_n(m)$$ for $$m\geqslant 1$$ . Their formulas may be viewed as the case $$m=1$$ in our result.
Terahertz spectroscopy of an electron-hole bilayer system in AlN/GaN/AlN quantum wells

We report studies on the nanoscale transport dynamics of carriers in strained AlN/GaN/AlN quantum wells: an electron-hole bilayer charge system with a large difference in transport properties between charge layers. From electronic band diagram analysis, the presence of spatially separated two-dimensional electron and hole charge layers is predicted at opposite interfaces. Since these charge layers exhibit distinct spectral signatures at terahertz frequencies, a combination of terahertz and far-infrared spectroscopy enables us to extract (a) individual contributions to the total conductivity and (b) effective scattering rates for charge-carriers in each layer. Furthermore, by comparing direct-current and THz-extracted conductivity levels, we are able to determine the extent to which structural defects affect charge transport. Our results evidence that (i) a non-unity Hall-factor and (ii) the considerable contribution of holes to the overall conductivity lead to a lower apparent mobility in Hall-effect meas...
Triggered Star Formation

Triggered star formation in bright rims and shells is reviewed. Shells are commonly observed in the Milky Way and other galaxies, but most diffuse shells seen in HI or the infrared do not have obvious triggered star formation. Dense molecular shells and pillars around HII regions often do have such triggering, although sometimes it is difficult to see what is triggered and what stars formed in the gas before the pressure disturbances. Pillar regions without clear age gradients could have their stars scattered by the gravity of the heads. Criteria and timescales for triggering are reviewed. The insensitivity of the average star formation rate in a galaxy to anything but the molecular mass suggests that triggering is one of many processes that lead to gravitational collapse and star formation.
Gradient flows without blow-up for Lefschetz thimbles

We propose new gradient flows that define Lefschetz thimbles and do not blow up in a finite flow time. We study analytic properties of these gradient flows, and confirm them by numerical tests in simple examples.
Adaptive Shrinkage Estimation for Streaming Graphs

Networks are a natural representation of complex systems across the sciences, and higher-order dependencies are central to the understanding and modeling of these systems. However, in many practical applications such as online social networks, networks are massive, dynamic, and naturally streaming, where pairwise interactions among vertices become available one at a time in some arbitrary order. The massive size and streaming nature of these networks allow only partial observation, since it is infeasible to analyze the entire network. Under such scenarios, it is challenging to study the higher-order structural and connectivity patterns of streaming networks. In this work, we consider the fundamental problem of estimating the higher-order dependencies using adaptive sampling. We propose a novel adaptive, single-pass sampling framework and unbiased estimators for higher-order network analysis of large streaming networks. Our algorithms exploit adaptive techniques to identify edges that are highly informative for efficiently estimating the higher-order structure of streaming networks from small sample data. We also introduce a novel James-Stein shrinkage estimator to reduce the estimation error. Our approach is fully analytic, computationally efficient, and can be incrementally updated in a streaming setting. Numerical experiments on large networks show that our approach is superior to baseline methods.
Averaged equation for energy diffusion on a graph reveals bifurcation diagram and thermally assisted reversal times in spin-torque driven nanomagnets

Driving nanomagnets by spin-polarized currents offers exciting prospects in magnetoelectronics, but the response of the magnets to such currents remains poorly understood. We show that an averaged equation describing the diffusion of energy on a graph captures the low-damping dynamics of these systems. From this equation we obtain the bifurcation diagram of the magnets, including the critical currents to induce stable precessional states and magnetization switching, as well as the mean times of thermally assisted magnetization reversal in situations where the standard reaction rate theory of Kramers is no longer valid. These results match experimental observations and give a theoretical basis for a Neel-Brown-type formula with an effective energy barrier for the reversal times.
A presentation for the baseleaf preserving mapping class group of the punctured solenoid

We give a presentation for the baseleaf preserving mapping class group MCG(H) of the punctured solenoid H. The generators for our presentation were introduced previously, and several relations among them were derived. In addition, we show that MCG(H) has no non-trivial central elements. Our main tool is a new complex of triangulations of the disk upon which MCG(H) acts.
Formal matched asymptotics for degenerate Ricci flow neckpinches

Gu and Zhu (2008 Commun. Anal. Geom. 16 467–94) have shown that type-II Ricci flow singularities develop from nongeneric rotationally symmetric Riemannian metrics on . In this paper, we describe and provide plausibility arguments for a detailed asymptotic profile and rate of curvature blow-up that we predict such solutions exhibit.
Transmission eigenvalues in one dimension

We show how to locate all the transmission eigenvalues for a one dimensional constant index of refraction on an interval.
The positive mass theorem with angular momentum and charge for manifolds with boundary

Motivated by the cosmic censorship conjecture in mathematical relativity, we establish the precise mass lower bound for an asymptotically flat Riemannian 3-manifold with nonnegative scalar curvature and minimal surface boundary, in terms of angular momentum and charge. In particular, this result does not require the restrictive assumptions of simple connectivity and completeness, which are undesirable from both a mathematical and physical perspective.
Stochastic kinetic theory for collective behavior of hydrodynamically interacting active particles

Self-propelled particles with hydrodynamic interactions (microswimmers) have previously been shown to produce long-range ordering phenomena. Many theoretical explanations for these collective phenomena are connected to instabilities in the hydrodynamic or kinetic equations. By incorporating stochastic fluxes into the mean field kinetic equation, we quantify the dynamics of a suspension of microswimmers in the parameter regime where the deterministic equation is stable. We can thereby compute nontrivial collective phenomena concerning spatial correlations of orientation and stress as well as the enhanced diffusion of tracer particles. Our analysis here focuses primarily on two-dimensional systems, though we also show how superdiffusion of tracers in three dimensions can occur by our framework.
AFTER RUNAWAY: THE TRANS-HILL STAGE OF PLANETESIMAL GROWTH

When planetesimals begin to grow by coagulation, they first enter an epoch of runaway, during which the biggest bodies grow faster than all the others. The questions of how runaway ends and what comes next have not been answered satisfactorily. We show that runaway is followed by a new stage—the "trans-Hill stage"—that commences when the bodies that dominate viscous stirring ("big bodies") become trans-Hill, i.e., when their Hill velocity matches the random speed of the small bodies they accrete. Subsequently, the small bodies' random speed grows in lockstep with the big bodies' sizes, such that the system remains in the trans-Hill state. Trans-Hill growth is crucial for determining the efficiency of growing big bodies, as well as their growth timescale and size spectrum. Trans-Hill growth has two sub-stages. In the earlier one, which occurs while the stirring bodies remain sufficiently small, the evolution is collisionless, i.e., collisional cooling among all bodies is irrelevant. The efficiency of forming big bodies in this collisionless sub-stage is very low, ~10α 1, where α ~ 0.005(a/AU)–1 is the ratio between the physical size of a body and its Hill radius. Furthermore, the size spectrum is flat (equal mass per size decade, i.e., q = 4). This collisionless trans-Hill solution explains results from previous coagulation simulations for both the Kuiper Belt and the asteroid belt. The second trans-Hill sub-stage commences once the stirring bodies grow big enough (>α–1 × the size of the accreted small bodies). After that time, collisional cooling among small bodies controls the evolution. The efficiency of forming big bodies rises and the size spectrum becomes more top heavy. Trans-Hill growth can terminate in one of two ways, depending on the sizes of the small bodies. First, mutual accretion of big bodies can become significant and conglomeration proceeds until half of the total mass is converted into big bodies. This mode of growth may explain the observed size distributions of small bodies in the solar system and is explored in our subsequent work. Second, if the big bodies' orbits become separated by their Hill radius, oligarchy commences. This mode likely precedes the formation of fully fledged planets.
A new approach to barrier-top fission dynamics

We proposed a calculational framework for describing induced fission that avoids the Bohr-Wheeler assumption of well-defined fission channels. The building blocks of our approach are configurations that form a discrete, orthogonal basis and can be characterized by both energy and shape. The dynamics is to be determined by in- teraction matrix elements between the states rather than by a Hill-Wheeler construction of a collective coordinate. Within our approach, several simple limits can be seen: diffu- sion; quantized conductance; and ordinary decay through channels. The specific proposal for the discrete basis is to use the K π quantum numbers of the axially symmetric Hartree- Fock approximation to generate the configurations. Fission paths would be determined by hopping from configuration to configuration via the residual interaction. We show as an example the configurations needed to describe a fictitious fission decay 32 S → 16 O + 16 O. We also examine the geometry of the path for fission of 236 U, measuring distances by the number of jumps needed to go to a new K π partition.
Higher-derivative terms in N = 2 supersymmetric effective actions

We show how to systematically construct higher-derivative terms in effective actions in harmonic superspace despite the infinite redundancy in their description due to the infinite number of auxiliary fields. Making an assumption about the absence of certain superspace Chern-Simons-like terms involving vector multiplets, we write all 3- and 4-derivative terms on Higgs, Coulomb, and mixed branches. Among these terms are several with only holomorphic dependence on fields, and at least one satisfies a non-renormalization theorem. These holomorphic terms include a novel 3-derivative term on mixed branches given as an integral over 3/4 of superspace. As an illustration of our method, we search for Wess-Zumino terms in the low energy effective action of N = 2 supersymmetric QCD. We show that such terms occur only on mixed branches. We also present an argument showing that the combination of space-time locality with supersymmetry implies locality in the anticommuting superspace coordinates of for unconstrained superfields.
Rate of parity violation from measure concentration

We present a geometric argument determining the kinematic (phase-space) factor contributing to the relative rate at which degrees of freedom of one chirality come to dominate over degrees of freedom of opposite chirality, in models with parity violation. We rely on the measure concentration of a subset of a Euclidean cube which is controlled by an isoperimetric inequality. We provide an interpretation of this result in terms of ideas of statistical mechanics.
Wormholes in f( R) gravity with a noncommutative-geometry background

This paper discusses the possible existence of traversable wormholes in f(R) modified gravity while assuming a noncommutative-geometry background, as well as zero tidal forces. The first part of the paper aims for an overview via several shape functions by determining the corresponding wormhole solutions and their properties. The solutions are made complete by deriving the modified-gravity functions F(r) and f(R), where $$F=df/dR$$ . It is subsequently shown that the violation of the null energy condition can be attributed to the combined effects of f(R) gravity and noncommutative geometry. The second part of the paper reverses the strategy by starting with a special form of f(R) and determining the wormhole solution and the concomitant F(r). The approach in this paper differs in significant ways from that of Jamil et al. (J Korean Phys Soc 65:917, 2014).
EXTRASOLAR GIANT MAGNETOSPHERIC RESPONSE TO STEADY-STATE STELLAR WIND PRESSURE AT 10, 5, 1, AND 0.2 au

A three-dimensional, multifluid simulation of a giant planet's magnetospheric interaction with steady-state stellar wind from a Sun-like star was performed for four different orbital semi-major axes - 10, 5, 1 and 0.2 AU. We simulate the effect of the increasing, steady-state stellar wind pressure related to the planetary orbital semi-major axis on the global magnetospheric dynamics for a Saturn-like planet, including an Enceladus-like plasma torus. Mass loss processes are shown to vary with orbital distance, with the centrifugal interchange instability displayed only in the 10 AU and 5 AU cases which reach a state of mass loss equilibrium more slowly than the 1 AU or 0.2 AU cases. The compression of the magnetosphere in the 1 AU and 0.2 AU cases contributes to the quenching of the interchange process by increasing the ratio of total plasma thermal energy to corotational energy. The strength of field-aligned currents (FAC), associated with auroral radio emissions, are shown to increase in magnitude and latitudinal coverage with a corresponding shift equatorward from increased dynamic ram pressure experienced in the hotter orbits. Similar to observed hot Jovian planets, the warm exo-Saturn simulated in the current work shows enhanced ion density in the magnetosheath and magnetopause regions, as well as the plasma torus which could contribute to altered transit signals, suggesting that for planets in warmer ($>$0.1 AU) orbits, planetary magnetic field strengths and possibly exomoons - via the plasma torus - could be observable with future missions.
K-theory and S-duality: starting over from square 3

Recently Maldacena, Moore, and Seiberg (MMS) have proposed a physical interpretation of the Atiyah-Hirzebruch spectral sequence, which roughly computes the K-homology groups that classify D-branes. We note that in IIB string theory, this approach can be generalized to include NS charged objects and conjecture an S-duality covariant, nonlinear extension of the spectral sequence. We then compute the contribution of the MMS double-instanton configuration to the derivation d5 and as an application compute the (p,q)-string spectrum on the group manifold SU(3). We conclude with an M-theoretic generalization reminiscent of 11-dimensional E8 gauge theory.
Poisson Chern-Simons gauge theory

We formulate Poisson Chern-Simons gauge theories on compact group manifolds. These describe a sector of the large representation limit of noncommutative Chern-Simons in the same way as the light-cone formulation of the membrane action describe a sector of the large N matrix model. While the formulation we give is on a group manifold, only excitations that are invariant under the left action of the stability group of a weight are allowed.
Dynamical constraints on the origin of Main Belt comets

In an effort to understand the origin of Main Belt comets (MBCs) 7968 Elst-Pizzaro, 118401, and P/2005 U1, the dynamics of these three icy asteroids and a large number of hypothetical MBCs were studied. Results of extensive numerical integrations of these objects suggest that they were formed in place through the collisional breakup of a larger precursor body. Simulations point specifically to the Themis family of asteroids as the origin of these objects and rule out the possibility of a cometary origin (i.e., inward scattering of comets from outer solar system and their primordial capture in the asteroid belt). Results also indicate that while 7968 Elst-Pizzaro and 118401 maintain their orbits for 1 Gyr, P/2005 U1 diffuses chaotically in eccentricity and becomes unstable in ~20 Myr. The latter suggest that this MBC used to be a member of the Themis family and is now escaping away. Numerical integrations of the orbits of hypothetical MBCs in the vicinity of the Themis family show a clustering of stable orbits (with eccentricities smaller than 0.2 and inclinations less than 25°) suggesting that many more MBCs may exist in the vicinity of this family (although they might have not been activated yet). The details of the results of simulations and the constraints on the models of the formation and origins of MBCs are presented and their implications for the detection of more of these objects are discussed.
Quantum algorithms to simulate many-body physics of correlated fermions

Physical systems with strongly correlated electrons (fermions) are notoriously difficult to study using traditional computers. Meanwhile, as programmable $q\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}m$ computers become a reality, efficient (and preferably general) quantum algorithms are needed, in the face of limited qubit-qubit connectivity in the near term. Addressing both problems, the authors develop quantum algorithms that run on two-dimensional qubit lattices with nearest-neighbor interactions, to simulate strongly correlated fermions. Their approach avoids the parity problem in mapping fermionic operators to qubit operators, with hardly any overhead, and can be used for a whole class of problems.
THE DIFFUSE GALACTIC FAR-ULTRAVIOLET SKY

We present an all-sky map of the diffuse Galactic far ultraviolet (1344-1786 A) background using Galaxy Evolution Explorer data, covering 65% of the sky with 11.79 arcmin2 pixels. We investigate the dependence of the background on Galactic coordinates, finding that a standard cosecant model of intensity is not a valid fit. Furthermore, we compare our map to Galactic all-sky maps of 100 μm emission, N H I column, and Hα intensity. We measure a consistent low level far-UV (FUV) intensity at zero points for other Galactic quantities, indicating a 300 photons cm–2 s–1 sr–1 A–1 non-scattered isotropic component to the diffuse FUV. There is also a linear relationship between FUV and 100 μm emission below 100 μm values of 8 MJy sr–1. We find a similar linear relationship between FUV and N H I below 1021 cm–2. The relationship between FUV and Hα intensity has no such constant cutoff. For all Galactic quantities, the slope of the linear portion of the relationship decreases with Galactic latitude. A modified cosecant model, taking into account dust scattering asymmetry and albedo, is able to accurately fit the diffuse FUV at latitudes above 20°. The best fit model indicates an albedo, a, of 0.62 ± 0.04 and a scattering asymmetry function, g, of 0.78 ± 0.05. Deviations from the model fit may indicate regions of excess FUV emission from fluorescence or shock fronts, while low latitude regions with depressed FUV emission are likely the result of self-shielding dusty clouds.
Associative array model of SQL, NoSQL, and NewSQL databases

The success of SQL, NoSQL, and NewSQL databases is a reflection of their ability to provide significant functionality and performance benefits for specific domains, such as financial transactions, internet search, and data analysis. The BigDAWG polystore seeks to provide a mechanism to allow applications to transparently achieve the benefits of diverse databases while insulating applications from the details of these databases. Associative arrays provide a common approach to the mathematics found in different databases: sets (SQL), graphs (NoSQL), and matrices (NewSQL). This work presents the SQL relational model in terms of associative arrays and identifies the key mathematical properties that are preserved within SQL. These properties include associativity, commutativity, distributivity, identities, annihilators, and inverses. Performance measurements on distributivity and associativity show the impact these properties can have on associative array operations. These results demonstrate that associative arrays could provide a mathematical model for polystores to optimize the exchange of data and execution queries.