cssi/SciSciGPT-SciSciNet huggingface dataset:
Software Mitigation of Crosstalk on Noisy Intermediate-Scale Quantum Computers

Crosstalk is a major source of noise in Noisy Intermediate-Scale Quantum (NISQ) systems and is a fundamental challenge for hardware design. When multiple instructions are executed in parallel, crosstalk between the instructions can corrupt the quantum state and lead to incorrect program execution. Our goal is to mitigate the application impact of crosstalk noise through software techniques. This requires (i) accurate characterization of hardware crosstalk, and (ii) intelligent instruction scheduling to serialize the affected operations. Since crosstalk characterization is computationally expensive, we develop optimizations which reduce the characterization overhead. On 3 20-qubit IBMQ systems, we demonstrate two orders of magnitude reduction in characterization time (compute time on the QC device) compared to all-pairs crosstalk measurements. Informed by these characterization, we develop a scheduler that judiciously serializes high crosstalk instructions balancing the need to mitigate crosstalk and exponential decoherence errors from serialization. On real-system runs on 3 IBMQ systems, our scheduler improves the error rate of application circuits by up to 5.6x, compared to the IBM instruction scheduler and offers near-optimal crosstalk mitigation in practice. In a broader picture, the difficulty of mitigating crosstalk has recently driven QC vendors to move towards sparser qubit connectivity or disabling nearby operations entirely in hardware, which can be detrimental to performance. Our work makes the case for software mitigation of crosstalk errors.
Demonstrating a directional detector based on neon for characterizing high energy neutrons

MITPC is a gas-based time projection chamber used for detecting fast, MeV-scale neutrons. The standard version of the detector relies on a mixture of 600 torr gas composed of 87.5% 4He and 12.5% CF4 for precisely measuring the energy and direction of neutron-induced nuclear recoils. We describe studies performed with a prototype detector investigating the use of Ne, as a replacement for 4He, in the gas mixture. Our discussion focuses on the advantages of Ne as the fast neutron target for high energy neutron events (100 MeV) and a demonstration that the mixture will be effective for this event class. We find that the achievable gain and transverse diffusion of drifting electrons in the Ne mixture are acceptable and that the detector uptime lost due to voltage breakdowns in the amplification plane is negligible, compared to ~ 20% with the 4He mixture.
On a Regularized Family of Models for Homogeneous Incompressible Two-Phase Flows

We consider a general family of regularized models for incompressible two-phase flows based on the Allen–Cahn formulation in $$n$$ -dimensional compact Riemannian manifolds for $$n=2,3$$ . The system we consider consists of a regularized family of Navier–Stokes equations (including the Navier–Stokes- $$\alpha $$ -like model, the Leray- $$\alpha $$ model, the modified Leray- $$\alpha $$ model, the simplified Bardina model, the Navier–Stokes–Voight model, and the Navier–Stokes model) for the fluid velocity $$u$$ suitably coupled with a convective Allen–Cahn equation for the order (phase) parameter $$\phi $$ . We give a unified analysis of the entire three-parameter family of two-phase models using only abstract mapping properties of the principal dissipation and smoothing operators and then use assumptions about the specific form of the parameterizations, leading to specific models, only when necessary to obtain the sharpest results. We establish existence, stability, and regularity results and some results for singular perturbations, which as special cases include the inviscid limit of viscous models and the $$\alpha \rightarrow 0$$ limit in $$\alpha $$ models. Then we show the existence of a global attractor and exponential attractor for our general model and establish precise conditions under which each trajectory $$\left( u,\phi \right) $$ converges to a single equilibrium by means of a Lojasiewicz–Simon inequality. We also derive new results on the existence of global and exponential attractors for the regularized family of Navier–Stokes equations and magnetohydrodynamics models that improve and complement the results of Holst et al. (J Nonlinear Sci 20(5):523–567, 2010). Finally, our analysis is applied to certain regularized Ericksen–Leslie models for the hydrodynamics of liquid crystals in $$n$$ -dimensional compact Riemannian manifolds.
Effective renormalized multi-body interactions of harmonically confined ultracold neutral bosons

We calculate the renormalized effective two-, three- and four-body interactions for N neutral ultracold bosons in the ground state of an isotropic harmonic trap, assuming two-body interactions modeled with the combination of a zero-range and energy-dependent pseudopotential. We work to third-order in the scattering length at(0) defined at zero collision energy, which is necessary to obtain both the leading-order effective four-body interaction and consistently include corrections for realistic two-body interactions. The leading-order, effective three- and four-body interaction energies are and , where ω and σ(ω) are the harmonic oscillator frequency and length, respectively, and energies are in units of ℏω. The one-standard deviation error ±0.0001 for the third-order coefficient in U3(ω) is due to numerical uncertainty in estimating a slowly converging sum; the other two coefficients are either analytically or numerically exact. The effective three- and four-body interactions can play an important role in the dynamics of tightly confined and strongly correlated systems. We also performed numerical simulations for a finite-range (FR) boson–boson potential, and it was comparison to the zero-range predictions which revealed that finite-range effects must be taken into account for a realistic third-order treatment. In particular, we show that the energy-dependent pseudopotential accurately captures, through third order, the finite-range physics, and in combination with the multi-body effective interactions gives excellent agreement with the numerical simulations, validating our theoretical analysis and predictions.
SATR-DL: Improving Surgical Skill Assessment And Task Recognition In Robot-Assisted Surgery With Deep Neural Networks

Purpose: This paper focuses on an automated analysis of surgical motion profiles for objective skill assessment and task recognition in robot-assisted surgery. Existing techniques heavily rely on conventional statistic measures or shallow modelings based on hand-engineered features and gesture segmentation. Such developments require significant expert knowledge, are prone to errors, and are less efficient in online adaptive training systems. Methods: In this work, we present an efficient analytic framework with a parallel deep learning architecture, SATR-DL, to assess trainee expertise and recognize surgical training activity. Through an end-to-end learning technique, abstract information of spatial representations and temporal dynamics is jointly obtained directly from raw motion sequences. Results: By leveraging a shared highlevel representation learning, the resulting model is successful in the recognition of trainee skills and surgical tasks, suturing, needle-passing, and knot-tying. Meanwhile, we explore the use of ensemble in classification at the trial level, where the SATR-DL outperforms state-of-the-art performance by achieving accuracies of 0.960 and 1.000 in skill assessment and task recognition, respectively. Conclusion: This study highlights the potential of SATR-DL to provide improvements for an efficient data-driven assessment in intelligent robotic surgery.
Optimization of Molecules via Deep Reinforcement Learning

We present a framework, which we call Molecule Deep Q-Networks (MolDQN), for molecule optimization by combining domain knowledge of chemistry and state-of-the-art reinforcement learning techniques (double Q-learning and randomized value functions). We directly define modifications on molecules, thereby ensuring 100% chemical validity. Further, we operate without pre-training on any dataset to avoid possible bias from the choice of that set. MolDQN achieves comparable or better performance against several other recently published algorithms for benchmark molecular optimization tasks. However, we also argue that many of these tasks are not representative of real optimization problems in drug discovery. Inspired by problems faced during medicinal chemistry lead optimization, we extend our model with multi-objective reinforcement learning, which maximizes drug-likeness while maintaining similarity to the original molecule. We further show the path through chemical space to achieve optimization for a molecule to understand how the model works.
Parallel Magnetic Resonance Imaging as Approximation in a Reproducing Kernel Hilbert Space.

In magnetic resonance imaging data samples are collected in the spatial frequency domain (k-space), typically by time-consuming line-by-line scanning on a Cartesian grid. Scans can be accelerated by simultaneous acquisition of data using multiple receivers (parallel imaging), and by using more efficient non-Cartesian sampling schemes. To understand and design k-space sampling patterns, a theoretical framework is needed to analyze how well arbitrary sampling patterns reconstruct unsampled k-space using receive coil information. As shown here, reconstruction from samples at arbitrary locations can be understood as approximation of vector-valued functions from the acquired samples and formulated using a reproducing kernel Hilbert space with a matrix-valued kernel defined by the spatial sensitivities of the receive coils. This establishes a formal connection between approximation theory and parallel imaging. Theoretical tools from approximation theory can then be used to understand reconstruction in k-space and to extend the analysis of the effects of samples selection beyond the traditional image-domain g-factor noise analysis to both noise amplification and approximation errors in k-space. This is demonstrated with numerical examples.
The tuning of light-matter coupling and dichroism in graphene for enhanced absorption: Implications for graphene-based optical absorption devices

The inter-band optical absorption in graphene characterized by its fine-structure constant has a universal value of 2.3% independent of the material parameters. However, for several graphene-based photonic applications, enhanced optical absorption is highly desired. In this work, we quantify the tunability of optical absorption in graphene via the Fermi level, angle of incidence of the incident polarized light, and the dielectric constants of the surrounding dielectric media in which graphene is embedded. The influence of impurities adsorbed on the surface of graphene on the Lorentzian broadening of the spectral function of the density of states is analytically evaluated within the equilibrium Green's function formalism. In all the cases, we find that absorption of light graphene embedded in dielectric medium is significantly higher than 2.3%. We also compute the differential absorption of right and left circularly-polarized light in graphene that is uniaxially and optically strained. The preferential absorption or circular dichroism is investigated for armchair and zigzag strain and the interplay of k-space and velocity anisotropy is examined. Finally, we relate circular dichroism to the Berry curvature of gapped graphene and explain the connection to parameters that define the underlying Hamiltonian.
Musings on the Current Status of HEP

I give a brief review of theoretical high energy physics as we know it today in the general picture of quantum physics. Prospects for future developments are outlined.
Spherical Cap Packing Asymptotics and Rank-Extreme Detection

We study the spherical cap packing problem with a probabilistic approach. Such probabilistic considerations result in an asymptotic sharp universal uniform bound on the maximal inner product between any set of unit vectors and a stochastically independent uniformly distributed unit vector. When the set of unit vectors are themselves independently uniformly distributed, we further develop the extreme value distribution limit of the maximal inner product, which characterizes its uncertainty around the bound. As applications of the above-mentioned asymptotic results, we derive: 1) an asymptotic sharp universal uniform bound on the maximal spurious correlation, as well as its uniform convergence in distribution when the explanatory variables are independently Gaussian distributed and 2) an asymptotic sharp universal bound on the maximum norm of a low-rank elliptically distributed vector, as well as related limiting distributions. With these results, we develop a fast detection method for a low-rank structure in high-dimensional Gaussian data without using the spectrum information.
Orbital angular momentum at small x

We determine the small Bjorken x asymptotics of the quark and gluon orbital angular momentum (OAM) distributions in the proton in the double-logarithmic approximation (DLA), which resums powers of αs ln2(1/x) with αs the strong coupling constant. Starting with the operator definitions for the quark and gluon OAM, we simplify them at small x, relating them, respectively, to the polarized dipole amplitudes for the quark and gluon helicities defined in our earlier works. Using the small-x evolution equations derived for these polarized dipole amplitudes earlier we arrive at the following small-x asymptotics of the quark and gluon OAM distributions in the large-Nc limit: 1a $$ {L}_{q+\overline{q}}\left(x,{Q}^2\right)=-\Delta \Sigma \left(x,{Q}^2\right)\sim {\left(\frac{1}{x}\right)}^{\frac{4}{\sqrt{3}}\kern0.5em \sqrt{\frac{\alpha_s\kern0.5em {N}_c}{2\pi }}}, $$ 1b $$ {L}_G\left(x,{Q}^2\right)\sim \Delta G\left(x,{Q}^2\right)\sim {\left(\frac{1}{x}\right)}^{\frac{13}{4\sqrt{3}}\kern0.5em \sqrt{\frac{\alpha_s\kern0.5em {N}_c}{2\pi }}}. $$
Ubiquitous quasi-Fuchsian surfaces in cusped hyperbolic 3-manifolds

This paper proves that every finite volume hyperbolic 3-manifold M contains a ubiquitous collection of closed, immersed, quasi-Fuchsian surfaces. These surfaces are ubiquitous in the sense that their preimages in the universal cover separate any pair of disjoint, non-asymptotic geodesic planes. The proof relies in a crucial way on the corresponding theorem of Kahn and Markovic for closed 3-manifolds. As a corollary of this result and a companion statement about surfaces with cusps, we recover Wise's theorem that the fundamental group of M acts freely and cocompactly on a CAT(0) cube complex.
Eclipsing Broad Emission Lines in Hercules X-1: Evidence for a Disk Wind?

We present disk wind model calculations for the broad emission lines seen in the ultraviolet spectra of the X-ray binary Hercules X-1. Recent HST/STIS observations of these lines suggest that they are kinematically linked to the orbital motion of the neutron star and exhibit a redshifted to blueshifted evolution of the line shape during the progression of the eclipse from ingress to egress that is indicative of disk emission. Furthermore, these lines are single peaked, which implies that they may be formed in a disk wind similar to those we have proposed as producing the broad emission lines seen in the UV spectra of active galactic nuclei. We compute line profiles as a function of eclipse phase and compare them to the observed line profiles. Various effects may modify the appearance of the lines including resonant scattering in the wind itself, self-shadowing of the warped disk from the central continuum, and self-obscuration of parts of the disk along the observer's line of sight. The latter two effects can cause orbital and precessional phase-dependent variations in the emission lines. Hence, examination of the line profiles as a function of these phases can, in principle, provide additional information on the characteristics of the disk warp.
ShapeShifter: Robust Physical Adversarial Attack on Faster R-CNN Object Detector

Given the ability to directly manipulate image pixels in the digital input space, an adversary can easily generate imperceptible perturbations to fool a Deep Neural Network (DNN) image classifier, as demonstrated in prior work. In this work, we propose ShapeShifter, an attack that tackles the more challenging problem of crafting physical adversarial perturbations to fool image-based object detectors like Faster R-CNN. Attacking an object detector is more difficult than attacking an image classifier, as it needs to mislead the classification results in multiple bounding boxes with different scales. Extending the digital attack to the physical world adds another layer of difficulty, because it requires the perturbation to be robust enough to survive real-world distortions due to different viewing distances and angles, lighting conditions, and camera limitations. We show that the Expectation over Transformation technique, which was originally proposed to enhance the robustness of adversarial perturbations in image classification, can be successfully adapted to the object detection setting. ShapeShifter can generate adversarially perturbed stop signs that are consistently mis-detected by Faster R-CNN as other objects, posing a potential threat to autonomous vehicles and other safety-critical computer vision systems. Code related to this paper is available at: https://github.com/shangtse/robust-physical-attack.
PROXIMA CENTAURI AS A BENCHMARK FOR STELLAR ACTIVITY INDICATORS IN THE NEAR-INFRARED

A new generation of dedicated Doppler spectrographs will attempt to detect low-mass exoplanets around mid-late M stars at near infrared (NIR) wavelengths, where those stars are brightest and have the most Doppler information content. A central requirement for the success of these instruments is to properly measure the component of radial velocity (RV) variability contributed by stellar magnetic activity and to account for it in exoplanet models of RV data. The wavelength coverage for many of these new instruments will not include the Ca II H&K or H-alpha lines, the most frequently used absorption-line tracers of magnetic activity. Thus, it is necessary to define and characterize NIR activity indicators for mid-late M stars in order to provide simultaneous activity metrics for NIR RV data. We have used the high-cadence UVES observations of the M5.5 dwarf Proxima Centauri from Fuhrmeister et al. (2011) to compare the activity sensitivity of 8 NIR atomic lines to that of H-alpha. We find that equivalent width-type measurements of the NIR K I doublet and the Ca II NIR triplet are excellent proxies for the canonical optical tracers. The Ca II triplet will be acquired by most of the new and upcoming NIR Doppler spectrographs, offering a common, reliable indicator of activity.
HIGHLY STABLE EVOLUTION OF EARTH'S FUTURE ORBIT DESPITE CHAOTIC BEHAVIOR OF THE SOLAR SYSTEM

Due to the chaotic nature of the solar system, the question of its dynamic long-term stability can only be answered in a statistical sense, for instance, based on numerical ensemble integrations of nearby orbits. Destabilization of the inner planets, including catastrophic encounters and/or collisions involving the Earth, has been suggested to be initiated through a large increase in Mercury's eccentricity (), with an estimated probability of ~1%. However, it has recently been shown that the statistics of numerical solar system integrations are sensitive to the accuracy and type of numerical algorithm. Here, I report results from computationally demanding ensemble integrations (N = 1600 with slightly different initial conditions) at unprecedented accuracy based on the full equations of motion of the eight planets and Pluto over 5 Gyr, including contributions from general relativity. The standard symplectic algorithm used for long-term integrations produced spurious results for highly eccentric orbits and during close encounters, which were hence integrated with a suitable Bulirsch–Stoer algorithm, specifically designed for these situations. The present study yields odds for a large increase in Mercury's eccentricity that are less than previous estimates. Strikingly, in two solutions, Mercury continued on highly eccentric orbits (after reaching values >0.93) for 80–100 Myr before colliding with Venus or the Sun. Most importantly, none of the 1600 solutions led to a close encounter involving the Earth or a destabilization of Earth's orbit in the future. I conclude that Earth's orbit will be dynamically highly stable for billions of years in the future, despite the chaotic behavior of the solar system.
MASTERING THE MASTER FIELD

Abstract The basic concepts of non-commutative probability theory are reviewed and applied to the large- N limit of matrix models. We argue that this is the appropriate framework for constructing the master field in terms of which large- N theories can be written. We explicitly construct the master field in a number of cases including QCD 2 . There we both give an explicit construction of the master gauge field and construct master loop operators as well. Most important we extend these techniques to deal with the general matrix model, in which the matrices do not have independent distributions and are coupled. We can thus construct the master field for any matrix model, in a well defined Hilbert space, generated by a collection of creation and annihilation operators—one for each matrix variable—satisfying the Cuntz algebra. We also discuss the equations of motion obeyed by the master field.
Kerr-Schild Double Copy and Complex Worldlines

We use the classical double copy to identify a necessary condition for Maxwell theory sources to constitute single copies of Kerr-Schild solutions to Einstein’s equations. In the case of four-dimensional Kerr-Schild spacetimes on Minkowski backgrounds, we extend this condition to a parameterization of the corresponding single copies. These are given by Lienard-Wiechert fields of charges on complex worldlines. This unifies the known instances of the Kerr-Schild double copy black holes on flat four-dimensional backgrounds into a single framework. Furthermore, we use the more generic condition identified to show why the black ring in five dimensions does not admit Kerr-Schild coordinates.
Intracluster Planetary Nebulae

I review the progress in research on intracluster planetary nebulae over the last five years. Hundreds more intracluster planetary nebulae have been detected in the nearby Virgo and Fornax galaxy clusters, searches of several galaxy groups have been made, and intracluster planetary candidates have been detected in the distant Coma cluster. The first theoretical studies of intracluster planetaries have also been completed, studying their utility as tracers of the intracluster light as a whole, and also as individual objects. From the results to date, it appears that intracluster planetaries are common in galaxy clus- ters (10-20% of the total amount of starlight), but thus far, none have been detected in galaxy groups, a result which currently is not well understood. Limited spectroscopic follow-up of intr- acluster planetaries in Virgo indicate that they have a complex velocity structure, in agreement with numerical models of intracluster light. Hydrodynamic simulations of individual intracluster planetaries predict that their morphology is significantly altered by their intracluster environ- ment, but their emission-line properties appear to be unaffected.
Transcriptional response of human articular chondrocytes treated with fibronectin fragments: an in vitro model of the osteoarthritis phenotype.

Summary Objective Fibronectin is a matrix protein that is fragmented during cartilage degradation in osteoarthritis (OA). Treatment of chondrocytes with fibronectin fragments (FN-f) has been used to model OA in vitro, but the system has not been fully characterized. This study sought to define the transcriptional response of chondrocytes to FN-f, and directly compare it to responses traditionally observed in OA. Design Normal human femoral chondrocytes isolated from tissue donors were treated with either FN-f or PBS (control) for 3, 6, or 18 h. RNA-seq libraries were compared between time-matched FN-f and control samples in order to identify changes in gene expression over time. Differentially expressed genes were compared to a published OA gene set and used for pathway, transcription factor motif, and kinome analysis. Results FN-f treatment resulted in 3,914 differentially expressed genes over the time course. Genes that are up- or downregulated in OA were significantly up- (P Conclusions FN-f treatment of normal human articular chondrocytes recapitulated many key aspects of the OA chondrocyte phenotype. This in vitro model is promising for future OA studies, especially considering its compatibility with genomics and genome-editing techniques.
Deep neural networks for the evaluation and design of photonic devices

The data-science revolution is poised to transform the way photonic systems are simulated and designed. Photonic systems are, in many ways, an ideal substrate for machine learning: the objective of much of computational electromagnetics is the capture of nonlinear relationships in high-dimensional spaces, which is the core strength of neural networks. Additionally, the mainstream availability of Maxwell solvers makes the training and evaluation of neural networks broadly accessible and tailorable to specific problems. In this Review, we show how deep neural networks, configured as discriminative networks, can learn from training sets and operate as high-speed surrogate electromagnetic solvers. We also examine how deep generative networks can learn geometric features in device distributions and even be configured to serve as robust global optimizers. Fundamental data-science concepts framed within the context of photonics are also discussed, including the network-training process, delineation of different network classes and architectures, and dimensionality reduction. Neural networks can capture nonlinear relationships in high-dimensional spaces and are powerful tools for photonic-system modelling. This Review discusses how deep neural networks can serve as surrogate electromagnetic solvers, inverse modelling tools and global device optimizers.
Readmission and Utilization After Repair of Ruptured Abdominal Aortic Aneurysms in the United States.

Objectives:Endovascular aneurysm repair (EVAR) has emerged as a less invasive alternative to open repair for ruptured Abdominal Aortic Aneurysms (rAAA), but comparisons to traditional open rAAA rep...
Directional Primitives for Uncertainty-Aware Motion Estimation in Urban Environments

We can use driving data collected over a long period of time to extract rich information about how vehicles behave in different areas of the roads. In this paper, we introduce the concept of directional primitives, which is a representation of prior information of road networks. Specifically, we represent the uncertainty of directions using a mixture of von Mises distributions and associated speeds using gamma distributions. These location-dependent primitives can be combined with motion information of surrounding vehicles to predict their future behavior in the form of probability distributions. Experiments conducted on highways, intersections, and roundabouts in the Carla simulator, as well as real-world urban driving datasets, indicate that primitives lead to better uncertainty-aware motion estimation.
Online Generalized Network Design Under (Dis)Economies of Scale

We consider a general online network design problem where a sequence of N requests arrive over time, each of which needs to use some subset of the available resources E. The cost incurred by any resource e is some function $f_e$ of the total load $L_e$ on that resource. The objective is to minimize the total cost $\sum_{e\in E} f_e(L_e)$. We focus on cost functions that exhibit (dis)economies of scale, that are of the form $f_e(x) = \sigma_e + \xi_e\cdot x^{\alpha_e}$ if $x>0$ (and zero if $x=0$), where the exponent $\alpha_e\ge 1$. Optimization problems under these functions have received significant recent attention due to applications in energy-efficient computing. Our main result is a deterministic online algorithm with tight competitive ratio $\Theta\left(\max_{e\in E} \left(\frac{\sigma_e}{\xi_e}\right)^{1/\alpha_e}\right)$ when $\alpha_e$ is constant for all $e\in E$. This framework is applicable to a variety of network design problems in undirected and directed graphs, including multicommodity routing, Steiner tree/forest connectivity and set-connectivity. In fact, our online competitive ratio even matches the previous-best (offline) approximation ratio for generalized network design.
Cellular birthdate predicts laminar and regional cholinergic projection topography in the forebrain.

The basal forebrain cholinergic system projects broadly throughout the cortex and constitutes a critical source of neuromodulation for arousal and attention. Traditionally, this system was thought to function diffusely. However, recent studies have revealed a high degree of spatiotemporal specificity in cholinergic signaling. How the organization of cholinergic afferents confers this level of precision remains unknown. Here, using intersectional genetic fate mapping, we demonstrate that cholinergic fibers within the mouse cortex exhibit remarkable laminar and regional specificity and that this is organized in accordance with cellular birthdate. Strikingly, birthdated cholinergic projections within the cortex follow an inside-out pattern of innervation. While early born cholinergic populations target deep layers, late born ones innervate superficial laminae. We also find that birthdate predicts cholinergic innervation patterns within the amygdala, hippocampus, and prefrontal cortex. Our work reveals previously unappreciated specificity within the cholinergic system and the developmental logic by which these circuits are assembled.
Can restructuring gains be sustained without ownership changes? evidence from withdrawn privatizations

By employing a novel, hand-collected sample of withdrawn and completed share issue privatizations, we show that both groups undergo comparable restructuring processes over the 3 years preceding the event. We employ matching procedures to explicitly control for the restructuring effect, isolating the effect of the ownership transfer from state to private investors on corporate policies and performance. We document that, absent the ownership transfer, most of the gains realized during the restructuring process are reabsorbed over the posttreatment period. The transition from state to private ownership thus represents a necessary condition for the long-term success of privatization programs.
Fixed or Floating Exchange Regimes; Does it Matter for Inflation?

This paper reviews recent experience with the choice of floating or fixed (“anchor”) exchange regimes in industrial and developing countries. It concludes that desirable differences between the two sets of regimes have narrowed, owing to the useful operational role of exchange rate margins and unavoidable medium-term rate adjustments in the context of fixed regimes. A survey of recent empirical cross-country literature also suggests little unambiguous association of the choice of exchange regime with macroeconomic performance, inflation in particular. Stability of the exchange rate has generally been a by-product of other policy choices. Even announcement effects of the regime on inflation-fighting credibility depend on the country-specific assignments of policy instruments to more than one institution--central bank, government, or regional and multilateral institutions.
Rethinking Regulatory Engagement Theory

Abstract We offer a constructive critique of Regulatory Engagement Theory (Higgins, E. T. (2006). Value from hedonic experience and engagement. Psychological Review, 113(3), 439–460.; Higgins, E. T., and Scholer, A. A. (2009). Engaging the consumer: The science and art of the value creation process. Journal of Consumer Psychology, 19(2).). After highlighting the major tenets of the theory and its main contributions, we identify some of its conceptual ambiguities. We then argue that the hedonic and intensity components of value may not be psychologically separable in that experiences acquire their hedonic quality through their intensity. We next discuss why the various determinants of strength of engagement proposed by the theory may not all operate through the same process. Even the regulatory fit phenomenon seems to involve more than one process. We conclude by suggesting that many strength-of-engagement effects may reflect feelings-as-information inferences consistent with the Generalized Affect-as-Information Model of judgment (GAIM; Pham, M. T. (2008). The lexicon and Grammar of Affect-as-Information: The GAIM. In M. Wanke (Ed.), Social psychology of consumer behavior. New York: Psychology Press.).
The Incoherence of Punishment in Antitrust

Antitrust began with the common law tort of restraint of trade but has long since separated itself from the rest of tort law, particularly in the area of punishment. Since the passage of the Sherman Act in 1890, the principal remedies for antitrust violations have been criminal penalties and private treble damage suits. Antitrust stands relatively unique in the American tort universe with its treble damage remedy, its lack of punitive damages, its rejection of in pari delicto defenses, and the peculiar combination of joint and several liability, the lack of contribution, and the way that settlements are credited against the potential liability of the remaining defendants in a case.
A Flexible Nonparametric Test for Conditional Independence

Author(s): Huang, Meng; Sun, Yixiao; White, Hal | Abstract: This paper proposes a nonparametric test for conditional independence that is easy to implement, yet powerful in the sense that it is consistent and achieves root-n local power. The test statistic is based on an estimator of the topological "distance" between restricted and unrestricted probability measures corresponding to conditional independence or its absence. The distance is evaluated using a family of Generically Comprehensively Revealing (GCR) functions, such as the exponential or logistic functions, which are indexed by nuisance parameters. The use of GCR functions makes the test able to detect any deviation from the null. We use a kernel smoothing method when estimating the distance. An integrated conditional moment (ICM) test statistic based on these estimates is obtained by integrating out the nuisance parameters. We simulate the critical values using a conditional simulation approach. Monte Carlo experiments show that the test performs well in Onite samples. As an application, we test the key assumption of unconfoundedness in the context of estimating the returns to schooling.
The Effects Of Competition On The Price For Cable Modem Internet Access

Abstract Theory suggests that a firm facing competition will raise prices as consumer preferences become more diverse, and with high enough diversity, a duopolist under product differentiation may price higher than a monopolist. Focusing on the price for cable modem Internet access, with or without DSL competition, and using the standard deviation of education attainment as a proxy for preference diversity, we find empirical support for these results. In markets where cable competes with DSL, the cable Internet price increases with preference diversity. Moreover, the cable Internet price under DSL competition can exceed that without competition when preferences are sufficiently diverse.
ON AN EVOLUTIONARY FOUNDATION OF NEUROECONOMICS

Neuroeconomics focuses on brain imaging studies mapping neural responses to choice behavior. Economic theory is concerned with choice behavior but it is silent on neural activities. We present a game theoretic model in which players are endowed with an addi- tional structure - a simple "nervous system" - and interact repeatedly in changing games. The nervous system constrains information processing functions and behavioral functions. By reinterpreting results from evolutionary game theory (Germano, 2007), we suggest that nervous systems can develop to "function well" in exogenously changing strategic environ- ments. We present an example indicating that an analogous conclusion fails if players can influence endogenously their environment.
A Call for Stricter Appellate Review of Decisions on Forum Non Conveniens

Forum non conveniens has been criticized as anachronistic and unfair. Critics say that it amounts to little more than economic protectionism, serving as a pretext for the dismissal of suits brought against domestic corporate defendants. Even if one does not view the doctrine as inherently flawed, it is undeniable that its application has been extremely uneven owing to the broad discretion exercised by district courts ruling on the issue. Troubling in any circumstances, the misapplication of forum non conveniens is all the more so because of the high stakes pertaining to the matter. When a case is dismissed on forum non conveniens, it usually goes away for good. Against this background, I argue that the appellate courts should adopt a stricter standard of review for decisions on forum non conveniens. The basic rubric (abuse of discretion) should stay the same, but the appellate courts should apply this standard with heightened scrutiny in light of the serious consequences of the underlying decision. The courts have done so in the analogous context of rulings on class certification. Doing so in the context of forum non conveniens would go a long way to curb abuse, all the while demonstrating to litigants and the broader community that the judiciary understands the importance of these decisions in today’s world.
Agenda control in the Bundestag, 1980–2002

We find strong evidence of monopoly legislative agenda control by government parties in the Bundestag. First, the government parties have near-zero roll rates, while the opposition parties are often rolled over half the time. Second, only opposition parties' (and not government parties') roll rates increase with the distances of each party from the floor median. Third, almost all policy moves are towards the government coalition (the only exceptions occur during periods of divided government). Fourth, roll rates for government parties skyrocket when they fall into the opposition and roll rates for opposition parties plummet when they enter government, while policy movements go from being nearly 100 per cent rightward when there is a rightist government to 100 per cent leftward under a leftist government.
Aiming at the Wrong Target: The "Audience Targeting" Test for Personal Jurisdiction in Internet Defamation Cases

In Young v. New Haven Advocate, 315 F.3d 256 (4th Cir. 2002), the Fourth Circuit crafted a jurisdictional test for Internet defamation that requires the plaintiff to show that the defendant specifically targeted an audience in the forum state for the state to exercise jurisdiction. This test relies on the presumption that the Internet—which is accessible everywhere—is targeted nowhere; it strongly protects foreign libel defendants who have published on the Internet from being sued outside of their home states. Other courts, including the North Carolina Court of Appeals, have since adopted or applied the test. The jurisdictional safe harbor (ironically) provided by the very ubiquity of the Internet is no doubt welcomed by media defendants and frequent Internet publishers (e.g., bloggers) whose use of the Internet exposes them to potentially nationwide jurisdiction for defamation. But it may go too far in protecting libel defendants from facing the consequences of their false and injurious statements. For every libel defendant insulated from jurisdiction in a remote location, there is also a libel plaintiff who has potentially been denied an effective remedy in a convenient location. This Article argues that the jurisdictional test created in Young is flawed and particularly should not be applied to libel defendants. It concludes with a simple suggestion: that the appropriate test for personal jurisdiction over libel defendants in cases of Internet defamation is the standard minimum contacts analysis.
Ideas have consequences: The Cold War and today

In this essay, I make the case that the Cold War was caused by a competition of ideas rather than by a struggle for power or a failure of international institutions. The Cold War started when two sets of ideas diverged sufficiently – capitalism and communism – that they precluded either a realist – spheres of influence – or liberal – United Nations – solution to postwar differences in Europe. It ended when one set of ideas prevailed, and democracy and markets spread throughout the whole of Europe, eclipsing realist and liberal outcomes. The Soviet Union disappeared, which realists never expected; whereas the United Nations, which functioned briefly as a classic liberal collective security operation in the first Persian Gulf War, was quickly replaced by a democratic NATO in Bosnia and Kosovo. The competition of ideas did not end in the 1990s, however. It continues today in other forms and will shape the contours of military conflict and international cooperation in tomorrow's world, no less that it did during the Cold War.
Beyond the Prisoners' Dilemma: Coordination, Game Theory, and Law

This article reviews the state of game theory in legal scholarship and finds that it remains excessively focused on one tool: the Prisoners' Dilemma. I claim that this focus is not justified, that it distracts legal scholars from exploiting other insights of game theory, particularly the problem of coordination. I show how the need for coordination is as pervasive and important to law as the Prisoners' Dilemma, illustrating with game theory discussions of constitutional law, international law, property disputes, traffic, culture, gender roles, and many other topics. I also explain how a focus on the Prisoners' Dilemma unnecessarily contributes to the divide between Law & Economics and Law & Society scholars, all of whom might find some common ground in exploring coordination games.
Dynamic Liquidity Preferences of Mutual Funds

This paper examines the relation between expected market volatility and open-end mutual funds’ liquidity preferences. Using a large panel of actively managed U.S. equity mutual funds, I show that m...
Capital market reactions to the passage of the Financial Services Modernization Act of 1999

Abstract The Financial Services Modernization Act of 1999, also known as the Gramm-Leach-Bliley Act (GLBA), removed most of the remaining barriers between financial companies. Stock market reactions to the passage of GLBA vary across financial sectors and company size. Specifically, we find negative returns for foreign banks, thrifts and finance companies; insignificant returns for banks; and positive returns for investment banks and insurance companies. Additionally, larger nondepository firms have higher returns. The return variation reflects resolution of uncertainty surrounding the final provisions of GLBA, competitive pressures, and expectations of future business combinations. Potential gains from business combinations may arise from economies of scope, market power, and/or from an implicit extension of government guarantees to banking affiliates.
Remembering the Public Domain

Rapid advances in communication technology over the past decade have resulted in the previously unimaginable ability to seamlessly exchange ideas and data on a global basis. Nonetheless, despite the undeniable progress that has been made, access to information is ironically becoming progressively more difficult. This is due in large part to the fact that resources which belong in the public domain are increasingly being transformed into private property. The carefully balanced provisions of copyright law are gradually becoming displaced by contractual, technological, and legislative constraints that allow for the tight control of access to and use of the materials in question. Although in limited circumstances generally unrestricted power to limit access and use may seem reasonable, in most situations this is not the case. Frequently the end results of such unwarranted restraints are considerable impediments to public access to ideas and information. Such a state of affairs has potentially serious consequences, as the ability to access and make use of these resources is critically important to creativity, competition, innovation, and a democratic culture. Unfortunately, lawmakers promulgating statutes and judges resolving disputes concerning data have failed to adequately take into account the multi-dimensional problems involved in disputes concerning access to information. The focus is often inappropriately centered on the tangible property within which information is contained, for example in a software program or a computer server. Additionally, once an owner of such property is ascertained, all of the conventional attributes of ownership are normally granted, including the right to exclude. As a result, almost insurmountable obstacles are faced by any other party whose interests might be affected by a lack of access, as the burden almost always falls on these other parties to explain why the previously identified owner's rights should be limited. Furthermore, facts and ideas increasingly are viewed merely as commodities in the marketplace, even though they constitute the building blocks of knowledge and are supposed to remain within the public domain. This myopic view of property rights fails to ensure that future creators, innovators, and participants in democratic culture have the benefit of these essential materials. Therefore, it is imperative that judges and policy makers give more comprehensive attention to the various interests involved in controversies affecting such resources and recognize that the way in which property rights are structured reflect the values we find important and the type of society we wish to create.