cssi/SciSciGPT-SciSciNet huggingface dataset:
Sensor Fusion and Planning with Perception–Action Network

Robot intelligence requires a real-time connection between sensing and action. A new computation principle of robotics that efficiently implements such a connection is utmost important for the new generation of robotics. In this paper, a perception–action network is presented as a means of efficiently integrating sensing, knowledge, and action for sensor fusion and planning. The network consists of a number of heterogeneous computational units, representing feature transformation and decision-making for action, which are interconnected as a dynamic system. New input stimuli to the network invoke the evolution of network states to a new equilibrium, through which a real-time integration of sensing, knowledge, and action can be accomplished. The network provides a formal, yet general and efficient, method of achieving sensor fusion and planning. This is because the uncertainties of signals, propagated in the network, can be controlled by modifying sensing parameters and robot actions. Algorithms for sensor planning based on the proposed network are established and applied to robot self-localization. Simulation and experimental results are shown.
Nano-robotic manipulation using a RRP nanomanipulator : Part A -Mathematical modeling and development of a robust adaptive driving mechanism

A three degree of freedom (3 DOF) nanomanipulator with revolute revolute prismatic (RRP) actuator structure, named here MM3A, can be utilized for a variety of nanomanipulation tasks. This first paper in the series presents the mathematical modeling and development of a memory-based robust adaptive controller for the nanomanipulator driving principle. Unlike widely used Cartesian-structure nanomanipulators, the MM3A is equipped with revolute-piezoelectric actuators which result in outstanding performance in controlling the nanomanipulator's tip alignment during the nanomanipulation. However, the RRP structure of the nanomanipulator introduces complexity in kinematic and dynamic equations of the system which needs to be addressed in order to control the nanomanipulation process. Dissimilar to the ordinary piezoelectric actuators which provide only a couple of micrometers working range, the piezoelectric actuators utilized in MM3A, namely Nanomotors®, provide wide range of action (120° in revolute actuators and 12 mm in prismatic actuator) with nanoscale precision (0.1 μrad in revolute actuators and 0.25 nm in prismatic actuator). This wide range of action combined with nanoscale precision is achieved using a special stick/slip moving principle of the Nanomotors®. However, such stick/slip motion results in stepping movement of the MM3A. Hence, due to the RRP structure and stepping movement principle of the MM3A nanomanipulator, development and implementation of an appropriate controller for such nanomanipulation process is not a trivial task. In this paper, a novel memory-based robust adaptive controller is proposed to overcome such shortfalls. Following the development the controller, numerical simulations are preformed to demonstrate the positioning performance capability of the controller in a variety of nanomanipulation tasks.
Progressive Regularization of Satellite-Based 3D Buildings for Interactive Rendering

Automatic creation of lightweight 3D building models from satellite image data enables large and widespread 3D interactive urban rendering. Towards this goal, we present an inverse procedural modeling method to automatically create building envelopes from satellite imagery. Our key observation is that buildings exhibit regular properties. Hence, we can overcome the low-resolution, noisy, and partial building data obtained from satellite by using a two stage inverse procedural modeling technique. Our method takes in point cloud data obtained from multi-view satellite stereo processing and produces a crisp and regularized building envelope suitable for fast rendering and optional projective texture mapping. Further, our results show highly complete building models with quality superior to that of other compared-to approaches.
Genetic relatedness cannot explain social preferences in black-and-white ruffed lemurs, Varecia variegata

Fission–fusion social dynamics are common among a number of vertebrate taxa, and yet the factors shaping these variable associations among subgroup members have not been widely addressed. Associations may occur simply because of shared habitat preferences; however, social ties may also be influenced by genetic relatedness (kinship) or social attraction. Here, we investigate the association patterns of wild black-and-white ruffed lemurs, Varecia variegata, in Ranomafana National Park, Madagascar using behavioural, spatial (home range) and genetic data from 24 individually identified animals. We collected 40 840 records of group composition over a 17-month period and from this calculated pairwise association indices. We also used ranging coordinates and genetic samples to estimate patterns of spatial overlap and kinship, and then related these measures to patterns of affiliation. From these analyses, we found that dyadic ruffed lemur social associations were generally sparse and weak, that home range overlap was minimal and that average relatedness within the community was low. We found no evidence that kinship was related to patterns of either spatial overlap or social association; instead, associations were primarily driven by space use. Moreover, social preferences were unrelated to kinship. While home range overlap explained most of the variation seen in social association, some variation remained unaccounted for, suggesting that other social, ecological and biological factors such as shared resource defence or communal breeding might also play a role in social attraction. Our results further highlight the need to consider individual space use and nuances of species behaviour when investigating social preference and social association more generally.
Social Networks, Personalized Advertising, and Privacy Controls

This article investigates how Internet users' perceptions of control over their personal information affect how likely they are to click on online advertising on a social networking website. The analysis uses data from a randomized field experiment that examined the effectiveness of personalizing ad text with user-posted personal information relative to generic text. The website gave users more control over their personally identifiable information in the middle of the field test. However, the website did not change how advertisers used data to target and personalize ads. Before the policy change, personalized ads did not perform particularly well. However, after this enhancement of perceived control over privacy, users were nearly twice as likely to click on personalized ads. Ads that targeted but did not use personalized text remained unchanged in effectiveness. The increase in effectiveness was larger for ads that used more unique private information to personalize their message and for target groups t...
M5-brane amplitudes

The dynamics of a probe M5-brane, embedded as a hypersurface in eleven-dimensional Minkowski spacetime, is described by a six-dimensional world-volume theory. This theory has a variety of interesting symmetries some of which are obscure in the Lagrangian formulation of the theory. However, as summarized in this review, an alternative approach is to construct all of its on-shell tree-level scattering amplitudes. This enables understanding all of the symmetries in a satisfying way. This work is dedicated to the memory of Peter Freund.
Air pollution reduction and mortality benefit during the COVID-19 outbreak in China.

To control the novel coronavirus disease (COVID-19) outbreak, China undertook stringent traffic restrictions and self-quarantine measures. We herein examine the change in air pollution levels and the potentially avoided cause-specific mortality during this massive population quarantine episode. We found that, due to the quarantine, NO2 dropped by 22.8 μg/m3 and 12.9 μg/m3 in Wuhan and China, respectively. PM2.5 dropped by 1.4 μg/m3 in Wuhan but decreased by 18.9 μg/m3 across 367 cities. Our findings show that interventions to contain the COVID-19 outbreak led to air quality improvements that brought health benefits which outnumbered the confirmed deaths due to COVID-19 in China
Effects of Defect Development During Displacive Austenite Reversion on Strain Hardening and Formability

Martensite that is mechanically induced from metastable austenite can be reversed to austenite upon annealing. The reversion transformation can be either diffusive or displacive, and the defect substructure development, in either case, has mechanical consequences. Here, to better understand the effects of microstructure development during displacive phase transformations, we focus on the influence of the initial plastic deformation on the austenite reversion (α′ → γ) in a transformation-induced plasticity-maraging steel. The phase transformation kinetics and the developing defect structure within the reversed γ phase are characterized by carrying out differential scanning calorimetry measurements, electron-backscattered diffraction, and electron channeling contrast imaging analyses. The resulting mechanical behavior is investigated by uniaxial and biaxial tension experiments. These investigations demonstrate that the defect development during sequential deformation-annealing treatments can help increase the overall strain hardening capacity of the alloy, which in turn increases the accumulative uniform elongation, and the formability. While the necking can be progressively delayed to higher strain levels following such treatments, the local fracture strain apparently cannot be, due to damage accumulation.
Hard Constraints: Why Telemanipulated Surgical Robots Affect Creative Tool Use

The operating room is fertile ground for creativity: problem solving is common, different surgical tasks impose particular constraints, and a wide range of tools are available. The introduction of telemanipulated robots in Minimally Invasive Surgery (MIS) has impacted the work of surgeons and their teams in terms of communication, use of perceptual senses, social structure, roles among other things. But do they also impact creativity? I present preliminary results of data re-analysis from an earlier field study focusing on creative tool use. Results suggest that current surgical robots limit creativity as they impose hard constraints: they remove haptic feedback, isolate the surgeon, and are built in rigid ways.
Replication using templates: Does the unit learn from itself, the template, or both?

Research Summary: Replication of practices is an important value‐creating strategy for multi‐unit firms, yet they often struggle to share knowledge internally across locations. Drawing on the replication and learning literatures and using data from a Fortune 100 retail chain that implemented a new restocking practice in 280 stores, I examine whether and how templates influence unit learning when replicating new practices. Stores were divided into districts, each with one randomly chosen template and 6–10 replicating stores. A replicating store's prior performance relative to that of its template influences the extent to which the store learns from the template versus from its own experience. These findings suggest that replication involves simultaneously and dynamically learning from both transferred knowledge and knowledge gained from experience. Managerial Summary: Transferring valuable practices within the firm is an important yet difficult task for many firm types, especially multi‐unit firms. One way that firms choose to transfer practices is through the use of templates—working examples of the new practice that act as models. Using data from a Fortune 100 retail chain, I show that the use of templates affects the way in which units learn to implement the practice. Because managers face tradeoffs when devoting attention to implementing the new practice, they must balance learning from the template with incorporating their own local experience with the new practice. Overall, my results suggest that choosing many templates is less important than choosing a few templates with superior performance for firms whose units or contexts are similar.
The behavioral impact of basic energy access: A randomized controlled trial with solar lanterns in rural India

Abstract How beneficial is basic energy access – typically lighting and mobile charging – for rural households? Despite research on the economic impacts of basic energy access, few studies have investigated how it changes household behavior. Here we report results from a randomized controlled trial in rural Uttar Pradesh, India, which identifies the behavioral impacts of providing solar lanterns to households that normally rely on kerosene as their primary source of lighting. Eighty-nine of the 184 households participating in the study were given a free, high-quality solar lantern. Comparing changes in responses from the baseline questionnaire and an endline questionnaires administered six months later, we find that the lanterns reduced energy expenditures, improved lighting, improved satisfaction with lighting, more use of lighting for domestic activities (e.g., reading), and improved satisfaction with lighting for domestic activities. Overall, our results show that basic energy access can offer substantial benefits within the households, even if broader rural economic transformation is not plausible.
Properties for the Fréchet mean in Billera-Holmes-Vogtmann treespace

Abstract The Billera-Holmes-Vogtmann (BHV) space of weighted trees can be embedded in Euclidean space, but the extrinsic Euclidean mean often lies outside of treespace. Sturm showed that the intrinsic Frechet mean exists and is unique in treespace. This Frechet mean can be approximated with an iterative algorithm, but bounds on the convergence of the algorithm are not known, and there is no other known polynomial algorithm for computing the Frechet mean nor even the edges present in the mean. We give the first necessary and sufficient conditions for an edge to be in the Frechet mean. The conditions are in the form of inequalities on the weights of the edges. These conditions provide a pre-processing step for finding the treespace orthant containing the Frechet mean. This work generalizes to orthant spaces.
Network Dependence Can Lead to Spurious Associations and Invalid Inference

Researchers across the health and social sciences generally assume that observations are independent, even while relying on convenience samples that draw subjects from one or a small number of comm...
Concrete polytopes may not tile the space

Brandolini et al. conjectured that all concrete lattice polytopes can multitile the space. We disprove this conjecture in a strong form, by constructing an infinite family of counterexamples in $\mathbb{R}^3$.
Social media and the city: Rethinking urban socio-spatial inequality using user-generated geographic information

Big data is increasingly seen as a way of providing a more ‘scientific’ approach to the understanding and management of cities. But most geographic analyses of geotagged social media data have failed to mobilize a sufficiently complex understanding of socio-spatial relations. By combining the conceptual approach of relational socio-spatial theory with the methods of critical GIScience, this paper explores the spatial imaginaries and processes of segregation and mobility at play in the notion of the ‘9th Street Divide’ in Louisville, Kentucky. Through a more context-sensitive analysis of this data, this paper argues against this popular spatial imaginary and the notion that the Louisville's West End is somehow separate and apart from the rest of the city. By analyzing the everyday activity spaces of different groups of Louisvillians through geotagged Twitter data, we instead argue for an understanding of these neighborhoods as fluid, porous and actively produced, rather than as rigid, static or fixed. Ultimately, this paper is meant to provide a conceptual and methodological framework for the analysis of social media data that is more attentive to the multiplicity of socio-spatial relations embodied in such data.
Order of Encoding Predicts Young Children's Responses to Sequencing Questions.

Abstract We propose that young children exhibit an order of encoding bias, such that they are inclined to report or act out events in the order in which they were originally encoded. This bias helps to explain why children assume that events they first hear described are in chronological order and why they often appear to understand “after” better than “before” when they are questioned about experienced events. Asking children about a sequence of events as a whole (in particular using “first”) could avoid order of encoding biases, because children would not have to answer questions about events within the sequence. In the present study, 100 2- to 4-year-old children participated in creating simple stories in which a story child interacted with five objects, thus creating five unrelated events. Children then responded to questions asking them to identify which action occurred “before” and “after” the third event and which action occurred “first” and “last” in the story. We hypothesized that (1) children would exhibit a tendency to answer “before” and “after” questions with the event that occurred after the queried event, thus impairing performance on “before” questions; (2) children would respond more accurately to questions about what occurred “first” and “last” than to questions about “before” and “after”; (3) children would respond more accurately to questions about “first” than questions about “last,” and (4) children’s performance would improve with age. The hypotheses were supported. Critically, children’s errors when responding to “before”/ “after” questions were consistent with an order of encoding bias.
Distributed Parameter Estimation in Randomized One-hidden-layer Neural Networks

This paper addresses distributed parameter estimation in randomized one-hidden-layer neural networks. A group of agents sequentially receive measurements of an unknown parameter that is only partially observable to them. In this paper, we present a fully distributed estimation algorithm where agents exchange local estimates with their neighbors to collectively identify the true value of the parameter. We prove that this distributed update provides an asymptotically unbiased estimator of the unknown parameter, i.e., the first moment of the expected global error converges to zero asymptotically. We further analyze the efficiency of the proposed estimation scheme by establishing an asymptotic upper bound on the variance of the global error. Applying our method to a real-world dataset related to appliances energy prediction, we observe that our empirical findings verify the theoretical results.
The Quadratic-Quadratic Regulator Problem: Approximating feedback controls for quadratic-in-state nonlinear systems

Feedback control problems involving autonomous quadratic systems are prevalent, yet very few software tools are available for approximating their solution. This paper represents a step forward in the special case where both the state equation and the control costs are quadratic. As it represents the natural extension of the linear-quadratic regulator (LQR) problem, we describe this setting as the quadratic-quadratic regulator (QQR) problem. We describe an algorithm that exploits the structure of the QQR problem that arises when implementing Al'Brekht's method. As we show, this well-known algorithm has an elegant formulation when written using Kronecker products and produces linear systems with a special structure that can take advantage of modern tensor-based linear solvers. We demonstrate this formulation on a random test problem then apply it to a discretized distributed parameter control problem that fits the QQR framework. This approach is amenable to low degree polynomial feedback laws in systems with modest model dimensions, for example, systems produced by modern model reduction methods. Comparisons to linear feedback control laws show a benefit in using the QQR formulation.
Combinatorial Nullstellensatz and DP-coloring of graphs

Abstract We initiate the study of applying the Combinatorial Nullstellensatz to the DP-coloring of graphs even though, as is well-known, the Alon–Tarsi theorem does not apply to DP-coloring. We define the notion of good covers of prime order which allows us to apply the Combinatorial Nullstellensatz to DP-coloring. We apply these tools to DP-coloring of the cones of certain bipartite graphs and uniquely 3-colorable graphs. We also extend a result of Akbari et al. (2006) on unique list colorability to the context of DP-coloring. We establish a sufficient algebraic condition for a graph G to satisfy χ D P ( G ) ≤ 3 , and we completely determine the DP-chromatic number of squares of all cycles.
Signatures of topological ground state degeneracy in Majorana islands

The authors study conductance and average charge in a Majorana island coupled to many normal metal leads. The topological ground state degeneracy leads to enhanced charge fluctuations and suppression of Coulomb blockade in conductance.
Combinatorial Black-Box Optimization with Expert Advice

We consider the problem of black-box function optimization over the Boolean hypercube. Despite the vast literature on black-box function optimization over continuous domains, not much attention has been paid to learning models for optimization over combinatorial domains until recently. However, the computational complexity of the recently devised algorithms are prohibitive even for moderate numbers of variables; drawing one sample using the existing algorithms is more expensive than a function evaluation for many black-box functions of interest. To address this problem, we propose a computationally efficient model learning algorithm based on multilinear polynomials and exponential weight updates. In the proposed algorithm, we alternate between simulated annealing with respect to the current polynomial representation and updating the weights using monomial experts' advice. Numerical experiments on various datasets in both unconstrained and sum-constrained Boolean optimization indicate the competitive performance of the proposed algorithm, while improving the computational time up to several orders of magnitude compared to state-of-the-art algorithms in the literature.
Regularity results for a penalized boundary obstacle problem

In this paper we are concerned with a two-penalty boundary obstacle problem of interest in thermics, fluid dynamics and electricity. Specifically, we prove existence, uniqueness and optimal regularity of the solutions, and we establish structural properties of the free boundary. A central role is played by the monotonicity of ad hoc Almgren- and Monneau-type functionals.
Real Lax spectrum implies spectral stability

We consider the dynamical stability of periodic solutions of integrable equations with 2x2 Lax pairs. We construct the eigenfunctions and hence the Floquet discriminant for such Lax pairs. The boundedness of the eigenfunctions determines the Lax spectrum. We use a connection between the Lax spectrum and the stability spectrum to show that the subset of the real line which gives rise to stable eigenvalues is contained in the Lax spectrum. This subset is the full spectrum for self-adjoint members of the AKNS hierarchy. For non-self-adjoint members of the AKNS hierarchy admitting a common reduction, the real line is always part of the Lax spectrum and maps to stable eigenvalues of the stability problem. We demonstrate our methods work for a variety of examples.
A sharp square function estimate for the cone in $\mathbb {R}^3$

We prove a sharp square function estimate for the cone in $\mathbb{R}^3$ and consequently the local smoothing conjecture for the wave equation in $2+1$ dimensions.
Developmental onset of enduring long‐term potentiation in mouse hippocampus

Analysis of long-term potentiation (LTP) provides a powerful window into cellular mechanisms of learning and memory. Prior work shows late LTP (L-LTP), lasting >3 hr, occurs abruptly at postnatal day 12 (P12) in the stratum radiatum of rat hippocampal area CA1. The goal here was to determine the developmental profile of synaptic plasticity leading to L-LTP in the mouse hippocampus. Two mouse strains and two mutations known to affect synaptic plasticity were chosen: C57BL/6J and Fmr1-/y on the C57BL/6J background, and 129SVE and Hevin-/- (Sparcl1-/- ) on the 129SVE background. Like rats, hippocampal slices from all of the mice showed test pulse-induced depression early during development that was gradually resolved with maturation by 5 weeks. All the mouse strains showed a gradual progression between P10-P35 in the expression of short-term potentiation (STP), lasting ≤1 hr. In the 129SVE mice, L-LTP onset (>25% of slices) occurred by 3 weeks, reliable L-LTP (>50% slices) was achieved by 4 weeks, and Hevin-/- advanced this profile by 1 week. In the C57BL/6J mice, L-LTP onset occurred significantly later, over 3-4 weeks, and reliability was not achieved until 5 weeks. Although some of the Fmr1-/y mice showed L-LTP before 3 weeks, reliable L-LTP also was not achieved until 5 weeks. L-LTP onset was not advanced in any of the mouse genotypes by multiple bouts of theta-burst stimulation at 90 or 180 min intervals. These findings show important species differences in the onset of STP and L-LTP, which occur at the same age in rats but are sequentially acquired in mice.
Redesign your in‐person course for online: Creating connections and promoting engagement for better learning

This spring, instructors moved their courses online in an emergency fashion as campuses were closed due to the pandemic. As colleges prepare for the next academic year, there is a need to provide flexible instruction that is more intentional for quality online learning. We taught two undergraduate courses online for the first time this spring and surveyed our students' reactions to the course experiences. From our experiences and student feedback, we identified design elements and activities that were beneficial in promoting student engagement, sense of connectivity, and learning. We describe four qualities for a successful transition to online learning: (a) big questions and core concepts; (b) peer groups including reflective writing; (c) outreach to broader scientific community; and (d) instructor's social presence in the class. Our experience gives us confidence that courses can be redesigned for online without compromising rigor or essential learning goals.
Bridge trisections in $\mathbb{CP}^2$ and the Thom conjecture

We develop new techniques for understanding surfaces in ℂℙ2 via bridge trisections. Trisections are a novel approach to smooth 4–manifold topology, introduced by Gay and Kirby, that provide an avenue to apply 3–dimensional tools to 4–dimensional problems. Meier and Zupan subsequently developed the theory of bridge trisections for smoothly embedded surfaces in 4–manifolds. The main application of these techniques is a new proof of the Thom conjecture, which posits that algebraic curves in ℂℙ2 have minimal genus among all smoothly embedded, oriented surfaces in their homology class. This new proof is notable as it completely avoids any gauge theory or pseudoholomorphic curve techniques.
Frequency Response Characteristic (FRC) Curve and Fast Frequency Response Assessment in High Renewable Power Systems.

This paper introduces a frequency response characteristic (FRC) curve and its application in high renewable power systems. In addition, the paper presents a method for fast frequency response assessment and frequency nadir prediction without performing dynamic simulations using detailed models. The proposed FRC curve and fast frequency response assessment method are useful for operators to understand frequency response performance of high renewable systems in real time.
Geometry, inference, complexity, and democracy

Decisions about how the population of the United States should be divided into legislative districts have powerful and not fully understood effects on the outcomes of elections. The problem of understanding what we might mean by "fair districting" intertwines mathematical, political, and legal reasoning; but only in recent years has the academic mathematical community gotten directly involved in the process. I'll report on recent progress in this area, how newly developed mathematical tools have affected real political decisions, and what remains to be done. This survey represents the content of a lecture presented by the author in the Current Events Bulletin session of the Joint Mathematics Meetings in January 2020.
Using indication embeddings to represent patient health for drug safety studies.

Objective The electronic health record is a rising resource for quantifying medical practice, discovering the adverse effects of drugs, and studying comparative effectiveness. One of the challenges of applying these methods to health care data is the high dimensionality of the health record. Methods to discover the effects of drugs in health data must account for tens of thousands of potentially relevant confounders. Our goal in this work is to reduce the dimensionality of the health data with the aim of accelerating the application of retrospective cohort studies to this data. Materials and methods Here, we develop indication embeddings, a way to reduce the dimensionality of health data while capturing information relevant to treatment decisions. We evaluate these embeddings using external data on drug indications. Then, we use the embeddings as a substitute for medical history to match patients and develop evaluation metrics for these matches. Results We demonstrate that these embeddings recover the therapeutic uses of drugs. We use embeddings as an informative representation of relationships between drugs, between health history events and drug prescriptions, and between patients at a particular time in their health history. We show that using embeddings to match cohorts improves the balance of the cohorts, even in terms of poorly measured risk factors like smoking. Discussion and conclusion Unlike other embeddings inspired by word2vec, indication embeddings are specifically designed to capture the medical history leading to the prescription of a new drug. For retrospective cohort studies, our low-dimensional representation helps in finding comparator drugs and constructing comparator cohorts.
From rubber bands to rational maps: A research report

This research report outlines work, partially joint with Jeremy Kahn and Kevin Pilgrim, which gives parallel theories of elastic graphs and conformal surfaces with boundary. On one hand, this lets us tell when one rubber band network is looser than another and, on the other hand, tell when one conformal surface embeds in another. We apply this to give a new characterization of hyperbolic critically finite rational maps among branched self-coverings of the sphere, by a positive criterion: a branched covering is equivalent to a hyperbolic rational map if and only if there is an elastic graph with a particular “self-embedding” property. This complements the earlier negative criterion of W. Thurston.
Localization theorems in topological Hochschild homology and topological cyclic homology

We construct localization cofibration sequences for the topological Hochschild homology (THH ) and topological cyclic homology (TC ) of small spectral categories. Using a global construction of the THH and TC of a scheme in terms of the perfect complexes in a spectrally enriched version of the category of unbounded complexes, the sequences specialize to localization cofibration sequences associated to the inclusion of an open subscheme. These are the targets of the cyclotomic trace from the localization sequence of Thomason‐Trobaugh in K ‐theory. We also deduce versions of Thomason’s blow-up formula and the projective bundle formula for THH and TC . 19D55; 14F43
Unification and New Particles at the LHC

Precision gauge coupling unification is one of the primary quantitative successes of low energy or split supersymmetry. Preserving this success puts severe restrictions on possible matter and gauge sectors that might appear at collider-accessible energies. In this work we enumerate new gauge sectors which are compatible with unification, consisting of horizontal gauge groups acting on vector-like matter charged under the Standard Model. Interestingly, almost all of these theories are in the supersymmetric conformal window at high energies and confine quickly after the superpartners are decoupled. For a range of scalar masses compatible with both moderately tuned and minimally split supersymmetry, the confining dynamics happen at the multi-TeV scale, leading to a spectrum of multiple spin-0 and spin-1 resonances accessible to the LHC, with unusual quantum numbers and striking decay patterns.
Stability of Hydraulic Shock Profiles

We establish nonlinear $$H^2\cap L^1 \rightarrow H^2$$ stability with sharp rates of decay in $$L^p$$, $$p\ge 2$$, of general hydraulic shock profiles, with or without subshocks, of the inviscid Saint-Venant equations of shallow water flow, under the assumption of Evans–Lopatinsky stability of the associated eigenvalue problem. We verify this assumption numerically for all profiles, giving in particular the first nonlinear stability results for shock profiles with subshocks of a hyperbolic relaxation system.
The Formation of Broad-Line Clouds in the Accretion Shocks of Active Galactic Nuclei

Recent work on the gas dynamics in the Galactic center has improved our understanding of the accretion processes in galactic nuclei, particularly with regard to properties such as the specific angular momentum distribution, density, and temperature of the inflowing plasma. With the appropriate extrapolation of the physical conditions, this information can be valuable in trying to determine the origin of the broad-line region (BLR) in active galactic nuclei (AGNs). In this paper, we explore various scenarios for cloud formation based on the underlying principle that the source of plasma is ultimately that portion of the gas trapped by the central black hole from the interstellar medium. Based on what we know about the Galactic center, it is likely that in highly dynamic environments such as this, the supply of matter is due mostly to stellar winds from the central cluster. Winds accreting onto a central black hole are subjected to several disturbances capable of producing shocks, including a Bondi-Hoyle flow, stellar wind-wind collisions, and turbulence. Shocked gas is initially compressed and heated out of thermal equilibrium with the ambient radiation field; a cooling instability sets in as the gas is cooled via inverse-Compton and bremsstrahlung processes. If the cooling time is less than the dynamical flow time through the shock region, the gas may clump to form the clouds responsible for broad-line emission seen in many AGN spectra. Clouds produced by this process display the correct range of densities and velocity fields seen in broad emission lines. Very importantly, the cloud distribution agrees with the results of reverberation studies, in which it is seen that the central line peak (due to infalling gas at large radii) responds more slowly to continuum changes than the line wings, which originate in the faster moving, circularized clouds at smaller radii. Finally, we provide an example of fitting an observed line profile using the parameters specified by our model.
Comments on half S-branes

Following [18], we write the boundary state of half S-brane in bosonic string theory as a grand canonical partition function of a unitary matrix model. From this representation, it follows that the annulus amplitude can be written as a grand canonical partition function of a unitary two-matrix model. We also show that the contribution of the exponentially growing couplings to the timelike oscillators can be resummed in a certain annulus amplitude.
Collective Josephson vortex dynamics in long Josephson junction stacks

Abstract We investigate the collective phase dynamics in conventional long Josephson junction (LJJ) stacks and in layered superconductors, exhibiting intrinsic LJJ behaviors. Using a theoretical model which accounts for both the magnetic induction effect and the breakdown of local charge neutrality (i.e., charging effect), we show that the collective motion of Josephson vortices, including the dispersion of Josephson plasma mode and the Swihart-type velocity, in an intrinsic LJJ stack such as Bi 2 Sr 2 CaCu 2 O 8+ y (BSCCO) is significantly modified from those in a conventional LJJ stack. In BSCCO, the strength of the charging effect α is small (i.e., α ∼0.1–0.4), but it leads to notable changes in collective phase dynamics, including changes to the stability condition. Also, we show that splitting of the supercurrent branch in the resistive state is due to collective motion of Josephson vortices. The width of spread of these sub-branches in the linear current–voltage regime depends on α , suggesting another way to measure the charging effect in BSCCO.
MASSIVE SUPERSTRINGS ARE BLACK HOLES

We argue that it is inconsistent to ignore backreaction for on-shell superstring states at the Planck mass and beyond, and that these quantum states become rotating black holes in the classical limit. Consequences are discussed.
Decaying dark matter and the deficit of dwarf haloes

The hierarchical clustering inherent in �-CDM cosmology seems to produce many of the observed characteristics of large-scale structure. Bu t some glaring problems still remain, including the over-prediction (by a factor 10) of th e number of dwarf galaxies within the virialized population of the local group. Sev eral secondary effects have already been proposed to resolve this problem. It is still no t clear, however, whether the principal solution rests with astrophysical processes , such as early feedback from supernovae, or possibly with as yet undetermined properties of the dark matter itself. In this paper, we carry out a detailed calculation of the dwarf halo evolution incorporating the effects of a hypothesized dark-matter decay, D→ D ′ + l, where D is ˙
Conical metrics on Riemann surfaces, I: The compactified configuration space and regularity

We introduce a compactification of the space of simple positive divisors on a Riemann surface, as well as a compactification of the universal family of punctured surfaces above this space. These are real manifolds with corners. We then study the space of constant curvature metrics on this Riemann surface with prescribed conical singularities at these divisors. Our interest here is in the local deformation for these metrics, and in particular the behavior of these families as conic points coalesce. We prove a sharp regularity theorem for this phenomenon in the regime where these metrics are known to exist. This setting will be used in a subsequent paper to study the space of spherical conic metrics with large cone angles, where the existence theory is still incomplete. Of independent interest is how setting up the analysis on these compactified configuration spaces provides a good framework for analyzing “confluent families” of regular singular, ie conic, elliptic differential operators.
Three Dynamical Evolution Regimes for Coupled Ring-satellite Systems and Implications for the Formation of the Uranian Satellite Miranda

In coupled ring-satellite systems, satellites exchange angular momentum with both the primary through tides and with the ring through Lindblad torques, and may exchange material with the ring through accretion and tidal disruption. Here we show that these coupled ring-satellite systems fall into three distinct dynamical regimes, which we refer to as `Boomerang,' `Slingshot,' and `Torque-Dependent.' These regimes are determined by the relative locations of the Fluid Roche Limit, the synchronous orbit, and the location of the maximum orbit that Lindblad torques can perturb a satellite. Satellites that accrete from rings in the Boomerang regime remain interior to the synchronous orbit, and may be driven back toward the primary by tides. Satellites that accrete from rings in the Slingshot regime form exterior to the synchronous orbit, and are always driven away from the primary. Satellites that accrete from rings in the Torque-Dependent regime may exhibit either Boomerang or Slingshot behavior, depending on ring and satellite masses. We consider both known and hypothesized ring/satellite systems in the solar system, and identify which of these three regimes they fall into. We determine that Uranus exists within the Torque-Dependent regime. Using the RING-MOONS code, which models the dynamical evolution of coupled ring-satellite systems, we show that the Uranian satellite Miranda may have accreted from a massive ancient Roche-interior ring and followed a Slingshot-like dynamical path to its present orbit beyond the synchronous orbit, while satellites that accreted after Miranda followed Boomerang-like evolution paths and remained interior to the synchronous orbit.
Thermodynamic properties of Kagome antiferromagnets with different perturbations

We discuss the results of several small perturbations to the thermodynamic properties of Kagome Lattice Heisenberg Model (KLHM) at high and intermediate temperatures, including Curie impurities, dilution, in-plane and out of plane Dzyaloshinski-Moria (DM) anisotropies and exchange anisotropy. We examine the combined role of Curie impurities and dilution in the behavior of uniform susceptibility. We also study the changes in specific heat and entropy with various anisotropies. Their relevance to newly discovered materials ZnCu3(OH)6Cl2 is explored. We find that the magnetic susceptibility is well described by about 6 percent impurity and dilution. We also find that the entropy difference between the material and KLHM is well described by the DM parameter Dz/J ? 0:1.
Ergodic Fading MIMO Dirty Paper and Broadcast Channels: Capacity Bounds and Lattice Strategies

A multiple-input multiple-output (MIMO) version of the dirty paper channel is studied, where the channel input and the dirt experience the same fading process, and the fading channel state is known at the receiver. This represents settings where signal and interference sources are co-located, such as in the broadcast channel. First, a variant of Costa’s dirty paper coding is presented, whose achievable rates are within a constant gap to capacity for all signal and dirt powers. In addition, a lattice coding and decoding scheme is proposed, whose decision regions are independent of the channel realizations. Under Rayleigh fading, the gap to capacity of the lattice coding scheme vanishes with the number of receive antennas, even at finite Signal-to-Noise Ratio (SNR). Thus, although the capacity of the fading dirty paper channel remains unknown, this paper shows it is not far from its dirt-free counterpart. The insights from the dirty paper channel directly lead to transmission strategies for the two-user MIMO broadcast channel, where the transmitter emits a superposition of desired and undesired (dirt) signals with respect to each receiver. The performance of the lattice coding scheme is analyzed under different fading dynamics for the two users, showing that high-dimensional lattices achieve rates close to capacity.
Strange metallicity in the doped Hubbard model

Strange or bad metallic transport, defined by incompatibility with the conventional quasiparticle picture, is a theme common to many strongly correlated materials, including high-temperature superconductors. The Hubbard model represents a minimal starting point for modeling strongly correlated systems. Here we demonstrate strange metallic transport in the doped two-dimensional Hubbard model using determinantal quantum Monte Carlo calculations. Over a wide range of doping, we observe resistivities exceeding the Mott-Ioffe-Regel limit with linear temperature dependence. The temperatures of our calculations extend to as low as 1/40 of the noninteracting bandwidth, placing our findings in the degenerate regime relevant to experimental observations of strange metallicity. Our results provide a foundation for connecting theories of strange metals to models of strongly correlated materials.
Nearby cycles of Whittaker sheaves on Drinfeld’s compactification

In this article we give a geometric construction of a tilting perverse sheaf on Drinfeld’s compactification, by applying the nearby cycles functor to a family of nondegenerate Whittaker sheaves. Its restrictions along the defect stratification are shown to be certain perverse sheaves attached to the nilpotent radical of the Langlands dual Lie algebra. We also describe the subquotients of the monodromy filtration using the Picard–Lefschetz oscillators introduced by Schieder. We give an argument that the subquotients are semisimple based on the action, constructed by Feigin, Finkelberg, Kuznetsov, and Mirkovic, of the Langlands dual Lie algebra on the global intersection cohomology of quasimaps into flag varieties.
Interactive Fiction Game Playing as Multi-Paragraph Reading Comprehension with Reinforcement Learning.

Interactive Fiction (IF) games with real human-written natural language texts provide a new natural evaluation for language understanding techniques. In contrast to previous text games with mostly synthetic texts, IF games pose language understanding challenges on the human-written textual descriptions of diverse and sophisticated game worlds and language generation challenges on the action command generation from less restricted combinatorial space. We take a novel perspective of IF game solving and re-formulate it as Multi-Passage Reading Comprehension (MPRC) tasks. Our approaches utilize the context-query attention mechanisms and the structured prediction in MPRC to efficiently generate and evaluate action outputs and apply an object-centric historical observation retrieval strategy to mitigate the partial observability of the textual observations. Extensive experiments on the recent IF benchmark (Jericho) demonstrate clear advantages of our approaches achieving high winning rates and low data requirements compared to all previous approaches.
Structure and Energetics of Helium Adsorption on Nanosurfaces

The ground and excited state properties of small helium clusters, 4 He N , containing nanoscale (∼3-10 A) planar aromatic molecules have been studied with quantum Monte Carlo methods. Ground state structures and energies are obtained from importance-sampled, rigid-body diffusion Monte Carlo. Excited state energies due to helium vibrational motion are evaluated using the projection operator, imaginary time spectral evolution technique. We examine the adsorption of N helium atoms (N < 24) on a series of planar aromatic molecules (benzene, naphthalene, anthracene, tetracene, phthalocyanine). The first layer of helium atoms is well-localized on the molecule surface, and we find well-defined localized excitations due to in-plane vibrational motion of helium on the molecule surface. We discuss the implications of these confined excitations for the molecule spectroscopy.
A Redshift Survey of Nearby Galaxy Groups: The Shape of the Mass Density Profile

We constrain the mass profile and orbital structure of nearby groups and clusters of galaxies. Our method yields the joint probability distribution of the density slope n, the velocity anisotropy β, and the turnover radius r0 for these systems. The measurement technique does not use results from N-body simulations as priors. We incorporate 2419 new redshifts (included here) in the fields of 41 systems of galaxies with z 470 (95% confidence). We show that a simple, scale-free phase-space distribution function (DF) f(E,L2) ∝ (-E)α-1/2L-2β is consistent with the data as long as the matter density has a cusp. Using this DF, matter density profiles with constant-density cores (n = 0) are ruled out with better than 99.7% confidence.