cssi/SciSciGPT-SciSciNet huggingface dataset:
A Robust Test of Evolution near the Tip of the Red Giant Branch and Missing Giants in NGC 2808

We describe a new method for robustly testing theoretical predictions of red giant evolution near the tip of the giant branch. When theoretical cumulative luminosity functions are shifted to align the tip in the I band and normalized at a luminosity level slightly brighter than the red giant bump, virtually all dependence on age and composition (heavy elements and helium abundance) is eliminated. While significant comparisons with observations require large samples of giant stars, such samples are available for some of the most massive Milky Way globular clusters. We present comparisons with the clusters NGC 2808 and M5 and find that NGC 2808 has a deficiency of bright giants (with a probability of less than about 3% that a more extreme distribution of giant stars would have happened by chance). We discuss the possibilities that underestimated neutrino losses or strong mass loss could be responsible for the deficit of giants. While we cannot rule out the neutrino hypothesis, it cannot explain the apparent agreement between the M5 observations and models. On the other hand, strong mass loss provides a potential link between the giant star observations and NGC 2808's unusually blue horizontal branch. If the mass loss hypothesis is true, there is likely a significant population of He white dwarfs that could be uncovered with slightly deeper UV observations of the cluster.
A new approach to nonlinear constrained Tikhonov regularization

We present a novel approach to nonlinear constrained Tikhonov regularization from the viewpoint of optimization theory. A second-order sufficient optimality condition is suggested as a nonlinearity condition to handle the nonlinearity of the forward operator. The approach is exploited to derive convergence rate results for a priori as well as a posteriori choice rules, e.g., discrepancy principle and balancing principle, for selecting the regularization parameter. The idea is further illustrated on a general class of parameter identification problems, for which (new) source and nonlinearity conditions are derived and the structural property of the nonlinearity term is revealed. A number of examples including identifying distributed parameters in elliptic differential equations are presented.
Superhorizon entanglement entropy from particle decay in inflation.

In inflationary cosmology all particle states decay as a consequence of the lack of kinematic thresholds. The decay of an initial single particle state yields an entangled quantum state of the product particles. We generalize and extend a manifestly unitary field theoretical method to obtain the time evolution of the quantum state. We consider the decay of a light scalar field with mass M ≪ H with a cubic coupling in de Sitter space-time. Radiative corrections feature an infrared enhancement manifest as poles in � = M 2 /3H 2 and we obtain the quantum state
THE DETAILED CHEMICAL PROPERTIES OF M31 STAR CLUSTERS. I. Fe, ALPHA AND LIGHT ELEMENTS ∗

We present ages, Fe/H] and abundances of the a elements Ca I, Si I, Ti I, Ti II, and light elements Mg I, Na I, and Al I for 31 globular clusters (GCs) in M31, which were obtained from high-resolution, high signal-to-noise ratio > 60 echelle spectra of their integrated light (IL). All abundances and ages are obtained using our original technique for high-resolution IL abundance analysis of GCs. This sample provides a never before seen picture of the chemical history of M31. The GCs are dispersed throughout the inner and outer halo, from 2.5 kpc < R_(M31) < 117 kpc. We find a range of Fe/H] within 20 kpc of the center of M31, and a constant Fe/H] ~-1.6 for the outer halo clusters. We find evidence for at least one massive GC in M31 with an age between 1 and 5 Gyr. The ɑ-element ratios are generally similar to the Milky Way GC and field star ratios. We also find chemical evidence for a late-time accretion origin for at least one cluster, which has a different abundance pattern than other clusters at similar metallicity. We find evidence for star-to-star abundance variations in Mg, Na, and Al in the GCs in our sample, and find correlations of Ca, Mg, Na, and possibly Al abundance ratios with cluster luminosity and velocity dispersion, which can potentially be used to constrain GC self-enrichment scenarios. Data presented here were obtained with the HIRES echelle spectrograph on the Keck I telescope.
Distance and Similarity Measures for Soft Sets

In Ref. 7, the authors use matrix representation-based distances of soft sets to introduce matching function and distance-based similarity measures. We first give counterexamples to show that their Definition 2.7 and Lemma 3.5(3) contain errors, then improve their Lemma 4.4 making it a corollary of our result. The fundamental assumption of Ref. 7 has been shown to be flawed. This motivates us to introduce set operations-based measures. We present a case (Example 6.7) where Majumdar-Samanta similarity measure produces an erroneous result but the measure proposed here decides correctly. Several properties of the new measures have been presented and finally the new similarity measures have been applied to the problem of financial diagnosis of firms.
Probing the scale of ALP interactions with Fermi blazars

Gamma-rays from cosmological sources contain information about gamma-ray interactions. Standard model and non-standard model photon interactions along the path between the source and the observer can lead to changes in the energy or state of the photons, which in turn alters the observed energy spectrum of the source. In general, these interactions are a function of photon energy as well as source distance. Here we show how existing high energy gamma-ray observations of blazars can be used to constrain the coupling of axion-like-particles (ALPs) to the photon. The same ALP-photon coupling that has been invoked to explain the observations of TeV blazars beyond their pair production horizon is shown to have a potential effect on the data set of Fermi blazars.
When and by how much can helper node selection improve regenerating codes

Regenerating codes (RCs) can significantly reduce the repair bandwidth of distributed storage networks. Initially, the analysis of RCs was based on the assumption that during the repair process, the newcomer does not distinguish (among all surviving nodes) which nodes to access, i.e., the newcomer is oblivious to the set of helpers being used. Such a scheme is termed the blind repair (BR) scheme. Nonetheless, it is intuitive in practice that the newcomer should access only those “good” helpers. This paper focuses on characterizing the effect of choosing the helper nodes in terms of the storage-bandwidth tradeoff. The results fully answer the following fundamental questions: Under what conditions does proactively choosing the helper nodes improve the storage-bandwidth tradeoff? Can this improvement be analytically quantified?
The Role of Pressure Anisotropy in Cosmic-Ray Hydrodynamics

Cosmic ray propagation in the Milky Way and other galaxies is largely diffusive, with mean free path determined primarily by pitch angle scattering from hydromagnetic waves with wavelength of order the cosmic ray gyroradius. In the theory of cosmic ray self confinement, the waves are generated by instabilities driven by the cosmic rays themselves. The dominant instability is due to bulk motion, or streaming, of the cosmic rays, parallel to the background magnetic field B, and transfers cosmic ray momentum and energy to the thermal gas as well as confining the cosmic rays. Classical arguments and recent numerical simulations show that self confinement due to the streaming instability breaks down unless the cosmic ray pressure and thermal gas density gradients parallel to B are aligned, a condition which is unlikely to always be satisfied We investigate an alternative mechanism for cosmic ray self confinement and heating of thermal gas based on pressure anisotropy instability. Although pressure anisotropy is demonstrably less effective than streaming instability as a self confinement and heating mechanism on global scales, it may be important on mesoscales, particularly near sites of cosmic ray injection.
Toward a microscopic description of flow near the jamming threshold

We study the relationship between microscopic structure and viscosity in non-Brownian suspensions. We argue that the formation and opening of contacts between particles in flow effectively leads to a negative selection of the contacts carrying weak forces. We show that an analytically tractable model capturing this negative selection correctly reproduces scaling properties of flows near the jamming transition. In particular, we predict that i) the viscosity η diverges with the coordination number z as η ∼ (zc − z)−(3+θ)/(1+θ), ii) the operator which governs flow displays a low-frequency mode that controls the divergence of viscosity, at a frequency ωmin ∼ (zc − z)(3+θ)/(2+2θ), and iii) the distribution of forces displays a scale f* that vanishes near jamming as f*/〈f〉 ∼ (zc − z)1/(1+θ) where θ characterizes the distribution of contact forces P(f) ∼ fθ at jamming, and where zc is the Maxwell threshold for rigidity.
STELLAR VELOCITY DISPERSION AND ANISOTROPY OF THE MILKY WAY INNER HALO

We measure the three components of velocity dispersion, $\sigma_{R},\sigma_{\theta},\sigma_{\phi}$, for stars within 6 < R < 30 kpc of the Milky Way using a new radial velocity sample from the MMT telescope. We combine our measurements with previously published data so that we can more finely sample the stellar halo. We use a maximum likelihood statistical method for estimating mean velocities, dispersions, and covariances assuming only that velocities are normally distributed. The alignment of the velocity ellipsoid is consistent with a spherically symmetric gravitational potential. From the spherical Jeans equation, the mass of the Milky Way is M(<12 kpc) = $1.3\times10^{11}$ M$_{\odot}$ with an uncertainty of 40%. We also find a region of discontinuity, 15 < R < 25 kpc, where the estimated velocity dispersions and anisotropies diverge from their anticipated values, confirming at high significance the break observed by others. We argue that this break in anisotropy is physically explained by coherent stellar velocity structure in the halo, such as the Sgr stream. To significantly improve our understanding of halo kinematics will require combining radial velocities with future Gaia proper motions.
Advances in Global and Local Helioseismology: An Introductory Review

Helioseismology studies the structure and dynamics of the Sun’s interior by observing oscillations on the surface. These studies provide information about the physical processes that control the evolution and magnetic activity of the Sun. In recent years, helioseismology has made substantial progress towards the understanding of the physics of solar oscillations and the physical processes inside the Sun, thanks to observational, theoretical and modeling efforts. In addition to global seismology of the Sun based on measurements of global oscillation modes, a new field of local helioseismology, which studies oscillation travel times and local frequency shifts, has been developed. It is capable of providing 3D images of subsurface structures and flows. The basic principles, recent advances and perspectives of global and local helioseismology are reviewed in this article.
Characterizing the Circumgalactic Medium of Nearby Galaxies with HST/COS and HST/STIS Absorption-line Spectroscopy. II. Methods and Models*

We present basic data and modeling for a survey of the cool, photo-ionized Circum-Galactic Medium (CGM) of low-redshift galaxies using far-UV QSO absorption line probes. This survey consists of "targeted" and "serendipitous" CGM subsamples, originally described in Stocke et al. (2013, Paper 1). The targeted subsample probes low-luminosity, late-type galaxies at $z<0.02$ with small impact parameters ($\langle\rho\rangle = 71$ kpc), and the serendipitous subsample probes higher luminosity galaxies at $z\lesssim0.2$ with larger impact parameters ($\langle\rho\rangle = 222$ kpc). HST and FUSE UV spectroscopy of the absorbers and basic data for the associated galaxies, derived from ground-based imaging and spectroscopy, are presented. We find broad agreement with the COS-Halos results, but our sample shows no evidence for changing ionization parameter or hydrogen density with distance from the CGM host galaxy, probably because the COS-Halos survey probes the CGM at smaller impact parameters. We find at least two passive galaxies with H I and metal-line absorption, confirming the intriguing COS-Halos result that galaxies sometimes have cool gas halos despite no on-going star formation. Using a new methodology for fitting H I absorption complexes, we confirm the CGM cool gas mass of Paper 1, but this value is significantly smaller than found by the COS-Halos survey. We trace much of this difference to the specific values of the low-$z$ meta-galactic ionization rate assumed. After accounting for this difference, a best-value for the CGM cool gas mass is found by combining the results of both surveys to obtain $\log{(M/M_{\odot})}=10.5\pm0.3$, or ~30% of the total baryon reservoir of an $L \geq L^*$, star-forming galaxy.
Lower order terms in the 1-level density for families of holomorphic cuspidal newforms

The Katz-Sarnak density conjecture states that, in the limit as the analytic conductors tend to infinity, the behavior of normalized zeros near the central point of families of L-functions agree with the N → ∞ scaling limits of eigenvalues near 1 of subgroups of U(N). Evidence for this has been found for many families by studying the n-level densities; for suitably restricted test functions the main terms agree with random matrix theory. In particular, all one-parameter families of elliptic curves with rank r over Q(T ) and the same distribution of signs of functional equations have the same universal limiting behavior for their main term. We break this universality and find family dependent lower order correction terms in many cases; these lower order terms have applications ranging from excess rank to modeling the behavior of zeros near the central point, and depend on the arithmetic of the family. We derive an alternate form of the explicit formula for GL(2) L-functions which simplifies comparisons, replacing sums over powers of Satake parameters by sums of the moments of the Fourier coefficients λf (p). Our formula highlights the differences that we expect to exist from families whose Fourier coefficients obey different laws (for example, we expect Sato-Tate to hold only for non-CM families of elliptic curves). Further, by the work of Rosen and Silverman we expect lower order biases to the Fourier coefficients in one-parameter families of elliptic curves with rank over Q(T ); these biases can be seen in our expansions. We analyze several families of elliptic curves and see different lower order corrections, depending on whether or not the family has complex multiplication, a forced torsion point, or non-zero rank over Q(T ).
GENERAL RELATIVISTIC SIMULATIONS OF ACCRETION INDUCED COLLAPSE OF NEUTRON STARS TO BLACK HOLES

Neutron stars (NSs) in the astrophysical universe are often surrounded by accretion disks. Accretion of matter onto an NS may increase its mass above the maximum value allowed by its equation of state, inducing its collapse to a black hole (BH). Here we study this process for the first time, in three-dimensions, and in full general relativity. By considering three initial NS configurations, each with and without a surrounding disk (of mass ~7% M NS), we investigate the effect of the accretion disk on the dynamics of the collapse and its imprint on both the gravitational wave (GW) and electromagnetic (EM) signals that can be emitted by these sources. We show in particular that, even if the GW signal is similar for the accretion induced collapse (AIC) and the collapse of an NS in vacuum (and detectable only for Galactic sources), the EM counterpart could allow us to discriminate between these two types of events. In fact, our simulations show that, while the collapse of an NS in vacuum leaves no appreciable baryonic matter outside the event horizon, an AIC is followed by a phase of rapid accretion of the surviving disk onto the newly formed BH. The post-collapse accretion rates, on the order of ~10–2 M ☉ s–1, make these events tantalizing candidates as engines of short gamma-ray bursts.
Overcoming Cost Disadvantages in Procurement Auctions

An increasingly studied auction format is the asymmetric procurement auction, which features an advantaged bidder selling a good or service to a buyer. Such asymmetric setups, while generally believed to be more realistic, are also more complex. We investigate one such setting where one bidder has a cost advantage. Our central question is whether bidders who are cost-disadvantaged can overcome their inferior cost position. In a design that mirrors real construction procurement auctions, our laboratory experiment tests whether two information asymmetries (more precise cost estimates and knowledge about the cost estimating abilities of a competitor) allow cost-disadvantaged sellers to better compete. We begin by testing bidder performance in a procurement auction where the only asymmetry is due to a cost. In this setting, analytical benchmarks are known. We find – consistent with other studies – that all bidder types submit aggressive bids well below the Nash equilibrium predictions. Over time, subjects submit less aggressive bids, moving closer to what theory would predict. We then extend our experiments to include our novel, multiple asymmetry setup. We find that endowing cost-disadvantaged bidders with higher cost estimate precision benefits the bidder, as one might expect. Notably, providing market knowledge about a rival’s ability to estimate costs may not provide a benefit; in fact, it seems bidders are not able to use this information effectively and performance suffers. Finally, we show how bidders behave myopically when making these decisions. These implications raise important questions about how asymmetries interact in complex auction settings.
Demonstration of a quantized acoustic octupole topological insulator.

Recently introduced quantized multipole topological insulators (QMTIs) reveal new types of gapped boundary states, which themselves represent lower-dimensional topological phases and host symmetry protected zero-dimensional corner states. Inspired by these predictions, tremendous efforts have been devoted to the experimental observation of quantized quadrupole topological phase. However, due to stringent requirements of anti-commuting reflection symmetries, it is challenging to achieve higher-order quantized multipole moments, such as octupole moments, in a three-dimensional structure. Here, we overcome this challenge, and experimentally realize the acoustic analogue of a quantized octupole topological insulator using negatively coupled resonators. We confirm by first-principle studies that our design possesses a quantized octupole topological phase, and experimentally demonstrate spectroscopic evidence of a hierarchy of boundary modes, observing 3rd order topological corner states. Furthermore, we reveal topological phase transitions from higher- to lower-order multipole moments. Our work offers a pathway to explore higher-order topological states in 3D classical platforms. Although multipole topological insulators have been theoretically described and experimentally observed in 2D, third-order topological insulators in 3D have not been observed yet. Here, the authors realize for the first time a quantized octupole 3D topological state in an acoustic metamaterial.
How Shall We Use the Proteomics Toolbox for Biomarker Discovery

Biomarker discovery for clinical purposes is one of the major areas in which proteomics is used. However, despite considerable effort, the successes have been relatively scarce. In this perspective paper, we try to highlight and analyze the main causes for this limited success, and to suggest alternate strategies, which will avoid them, without eluding the foreseeable weak points of these strategies. Two major strategies are analyzed, namely, the switch from body fluids to cell and tissues for the initial biomarker discovery step or, if body fluids must be analyzed, the implementation of highly selective protein selection strategies.
Lattices from graph associahedra and subalgebras of the Malvenuto–Reutenauer algebra

The Malvenuto–Reutenauer algebra is a well-studied combinatorial Hopf algebra with a basis indexed by permutations. This algebra contains a wide variety of interesting sub Hopf algebras, in particular the Hopf algebra of plane binary trees introduced by Loday and Ronco. We compare two general constructions of subalgebras of the Malvenuto–Reutenauer algebra, both of which include the Loday–Ronco algebra. The first is a construction by Reading defined in terms of lattice quotients of the weak order, and the second is a construction by Ronco in terms of graph associahedra. To make this comparison, we consider a natural partial ordering on the maximal tubings of a graph and characterize those graphs for which this poset is a lattice quotient of the weak order.
Maximal pseudometrics and distortion of circle diffeomorphisms

We initiate a study of distortion elements in the Polish groups $\mbox{Diff}_+^k(\mathbb{S}^1)$ ($1\leq k<\infty$), as well as $\mbox{Diff}_+^{1+AC}(\mathbb{S}^1)$, in terms of maximal metrics on these groups. We classify distortion in the $k=1$ case: a $C^1$ circle diffeomorphism is $C^1$-undistorted if and only if it has a hyperbolic periodic point. On the other hand, answering a question of Navas, we exhibit analytic circle diffeomorphisms with only non-hyperbolic fixed points which are $C^{1+AC}$-undistorted, and hence $C^k$-undistorted for all $k\geq 2$. In the appendix, we exhibit a maximal metric on $\mbox{Diff}_+^{1+AC}(\mathbb{S}^1)$, and observe that this group is quasi-isometric to a hyperplane of $L^1(I)$.
A quantum-information-theoretic complement to a general-relativistic implementation of a beyond-Turing computer

There exists a growing literature on the so-called physical Church-Turing thesis in a relativistic spacetime setting. The physical Church-Turing thesis is the conjecture that no computing device that is physically realizable (even in principle) can exceed the computational barriers of a Turing machine. By suggesting a concrete implementation of a beyond-Turing computer in a spacetime setting, Istvan Nemeti and Gyula David (2006) have shown how an appreciation of the physical Church-Turing thesis necessitates the confluence of mathematical, computational, physical, and indeed cosmological ideas. In this essay, I will honour Istvan's seventieth birthday, as well as his longstanding interest in, and his seminal contributions to, this field going back to as early as 1987 by modestly proposing how the concrete implementation in Nemeti and D\'avid (2006) might be complemented by a quantum-information-theoretic communication protocol between the computing device and the logician who sets the beyond-Turing computer a task such as determining the consistency of Zermelo-Fraenkel set theory. This suggests that even the foundations of quantum theory and, ultimately, quantum gravity may play an important role in determining the validity of the physical Church-Turing thesis.
Influence of the Void Environment on Chemical Abundances in Dwarf Galaxies and Implications for Connecting Star Formation and Halo Mass

We study how the void environment affects the chemical evolution of galaxies by comparing the metallicity of dwarf galaxies in voids with dwarf galaxies in denser regions. Using spectroscopic observations from SDSS DR7, we estimate oxygen and nitrogen abundances of 889 void dwarf galaxies and 672 dwarf galaxies in denser regions. A substitute for the [OII] λ3727 doublet is developed, permitting oxygen abundance estimates of SDSS dwarf galaxies at all redshifts with the direct method. We find that void dwarf galaxies have about the same oxygen abundances and slightly lower N/O ratios than dwarf galaxies in denser environments. The lower N/O ratios seen in void dwarf galaxies may indicate both delayed star formation and a dependence of cosmic downsizing on the large-scale environment. Similar oxygen abundances in the two dwarf galaxy populations might be evidence of larger ratios of dark matter halo mass to stellar mass in voids.
Orthospectra of geodesic laminations and dilogarithm identities on moduli space

.We define the function LW T1.S/!S by letting L.v/D Length..v// . We note that L.v/ is measurable but can be infinite. We define measure M on the real line by M D L . Then M is a measure describing the distribution of the lengths of .v/ . We cut S along to obtain a surface with boundary denoted S . A ‐cusp of S is an ideal vertex of a component of S . We let N be the number of ‐cusps of S . We denote byf ig the geodesic arcs in S which have endpoints perpendicular to @S and denote the length of i by li . We note that if a component of S is an ideal k ‐gon then there are a finite number of geodesics i in this component. Otherwise there are an infinite number. We call the setflig (with multiplicities) the ‐orthospectrum. By doubling S we see that the ‐orthospectrum corresponds to a subset of the closed geodesics of a finite area surface and therefore is a countable set. We prove the following length spectrum identity
Detecting Invasive Insects with Unmanned Aerial Vehicles

A key aspect to controlling and reducing the effects invasive insect species have on agriculture is to obtain knowledge about the migration patterns of these species. Current state-of-the-art methods of studying these migration patterns involve a mark-release-recapture technique, in which insects are released after being marked and researchers attempt to recapture them later. However, this approach involves a human researcher manually searching for these insects in large fields and results in very low recapture rates. In this paper, we propose an automated system for detecting released insects using an unmanned aerial vehicle. This system utilizes ultraviolet lighting technology, digital cameras, and lightweight computer vision algorithms to more quickly and accurately detect insects compared to the current state of the art. The efficiency and accuracy that this system provides will allow for a more comprehensive understanding of invasive insect species migration patterns. Our experimental results demonstrate that our system can detect real target insects in field conditions with high precision and recall rates.
High energy cosmic rays

I review here some of the physics we are learning and expect to learn in the near future through the observation of cosmic rays. The study of cosmic rays involves a combination of data from accelerators, ground arrays, atmospheric fluorescence detectors and balloon and satellite experiments. I will discuss the data of the Pierre Auger Observatory, PAMELA, ATIC and FST among other experiments.
Few-shot Natural Language Generation for Task-Oriented Dialog

As a crucial component in task-oriented dialog systems, the Natural Language Generation (NLG) module converts a dialog act represented in a semantic form into a response in natural language. The success of traditional template-based or statistical models typically relies on heavily annotated data, which is infeasible for new domains. Therefore, it is pivotal for an NLG system to generalize well with limited labelled data in real applications. To this end, we present FewshotWOZ, the first NLG benchmark to simulate the few-shot learning setting in task-oriented dialog systems. Further, we develop the SC-GPT model. It is pre-trained on a large set of annotated NLG corpus to acquire the controllable generation ability, and fine-tuned with only a few domain-specific labels to adapt to new domains. Experiments on FewshotWOZ and the large Multi-Domain-WOZ datasets show that the proposed SC-GPT significantly outperforms existing methods, measured by various automatic metrics and human evaluations.
OBSERVATIONS OF THERMAL FLARE PLASMA WITH THE EUV VARIABILITY EXPERIMENT

One of the defining characteristics of a solar flare is the impulsive formation of very high temperature plasma. The properties of the thermal emission are not well understood, however, and the analysis of solar flare observations is often predicated on the assumption that the flare plasma is isothermal. The EUV Variability Experiment (EVE) on the Solar Dynamics Observatory provides spectrally resolved observations of emission lines that span a wide range of temperatures (e.g., Fe XV-Fe XXIV) and allow for thermal flare plasma to be studied in detail. In this paper we describe a method for computing the differential emission measure distribution in a flare using EVE observations and apply it to several representative events. We find that in all phases of the flare the differential emission measure distribution is broad. Comparisons of EVE spectra with calculations based on parameters derived from the Geostationary Operational Environmental Satellites soft X-ray fluxes indicate that the isothermal approximation is generally a poor representation of the thermal structure of a flare.
The solution gap of the Brezis–Nirenberg problem on the hyperbolic space

We consider the positive solutions of the nonlinear eigenvalue problem $$-\Delta _{\mathbb {H}^n} u = \lambda u + u^p, $$ with $$p=\frac{n+2}{n-2}$$ and $$u \in H_0^1(\Omega ),$$ where $$\Omega $$ is a geodesic ball of radius $$\theta _1$$ on $$\mathbb {H}^n.$$ For radial solutions, this equation can be written as an ordinary differential equation having n as a parameter. In this setting, the problem can be extended to consider real values of n. We show that if $$2<n<4$$ this problem has a unique positive solution if and only if $$\lambda \in \left( n(n-2)/4 +L^*\,,\, \lambda _1\right) .$$ Here $$L^*$$ is the first positive value of $$L = -\ell (\ell +1)$$ for which a suitably defined associated Legendre function $$P_{\ell }^{-\alpha }(\cosh \theta ) >0$$ if $$0 < \theta <\theta _1$$ and $$P_{\ell }^{-\alpha }(\cosh \theta _1)=0,$$ with $$\alpha = (2-n)/2$$ .
Resurgence, Painleve Equations and Conformal Blocks

We discuss some physical consequences of the resurgent structure of Painleve equations and their related conformal block expansions. The resurgent structure of Painleve equations is particularly transparent when expressed in terms of physical conformal block expansions of the associated tau functions. Resurgence produces an intricate network of inter-relations; some between expansions around different critical points, others between expansions around different instanton sectors of the expansions about the same critical point, and others between different non-perturbative sectors of associated spectral problems, via the Bethe-gauge and Painleve-gauge correspondences. Resurgence relations exist both for convergent and divergent expansions, and can be interpreted in terms of the physics of phase transitions. These general features are illustrated with three physical examples: correlators of the 2d Ising model, the partition function of the Gross-Witten-Wadia matrix model, and the full counting statistics of one dimensional fermions, associated with Painleve VI, Painleve III and Painleve V, respectively.
Spintronics on chiral objects

Chirality, handedness, is one of the most fundamental intriguing asymmetries in nature. By definition, chiral objects cannot be superimposed onto each other after mirror reflection operation. Numerous examples of chiral structures can be found in nature, for example, chiral molecules and chiral magnetic nanostructures. Moving electrons are associated with handedness by their own spins due to spin–orbit interaction thus exhibiting various emergent phenomena as they interact with chiral materials, which otherwise would not be observed in achiral systems. This new paradigm allows the potential development of new forms of devices or methods by utilizing reciprocal interaction of chiral objects with moving electron spins. This review updates the remarkable progresses in Spintronics on Chiral Objects that have been made over the past few years providing an outlook for new opportunities and potential applications with new insights.
Brightest Cluster Galaxy Alignments in Merging Clusters

Author(s): Wittman, D; Foote, D; Golovich, N | Abstract: The orientations of brightest cluster galaxies (BCGs) and their host clusters tend to be aligned, but the mechanism driving this is not clear. To probe the role of cluster mergers in this process, we quantify alignments of 38 BCGs in 22 clusters undergoing major mergers (up to ∼1 Gyr after first pericenter). We find alignments entirely consistent with those of clusters in general. This suggests that alignments are robust against major cluster mergers. If, conversely, major cluster mergers actually help orient the BCG, such a process is acting quickly because the orientation is in place within ∼1 Gyr after first pericenter.
Classical symmetries of some two-dimensional models coupled to gravity☆

Abstract This paper is a sequel to one in which we examined the affine symmetry algebras of arbitrary classical principal chiral models and symmetric space models in two dimensions. It examines the extension of those results in the presence of gravity. The main result is that even though the symmetry transformations of the fields depend on the gravitational background, the symmetry algebras of these classical theories are completely unchanged by the presence of arbitrary gravitational backgrounds. On the other hand, we are unable to generalize the Virasoro symmetries of the flat-space theories to theories with gravity.
Observing Exoplanets with High Dispersion Coronagraphy. I. The Scientific Potential of Current and Next-generation Large Ground and Space Telescopes

Direct imaging of exoplanets presents a formidable technical challenge owing to the small angular separation and high contrast between exoplanets and their host stars. High Dispersion Coronagraphy (HDC) is a pathway to achieve unprecedented sensitivity to Earth-like planets in the habitable zone. Here, we present a framework to simulate HDC observations and data analyses. The goal of these simulations is to perform a detailed analysis of the trade-off between raw star light suppression and spectral resolution for various instrument configurations, target types, and science cases. We predict the performance of an HDC instrument at Keck observatory for characterizing directly imaged gas-giant planets in near infrared bands. We also simulate HDC observations of an Earth-like planet using next-generation ground-based (TMT) and spaced-base telescopes (HabEx and LUVOIR). We conclude that ground-based ELTs are more suitable for HDC observations of an Earth-like planet than future space-based missions owing to the considerable difference in collecting area. For ground-based telescopes, HDC observations can detect an Earth-like planet in the habitable zone around an M dwarf star at 10^(−4) starlight suppression level. Compared to the 10^(−7) planet/star contrast, HDC relaxes the starlight suppression requirement by a factor of 10^3. For space-based telescopes, detector noise will be a major limitation at spectral resolutions higher than 10^4. Considering detector noise and speckle chromatic noise, R=400 (1600) is the optimal spectral resolutions for HabEx(LUVOIR). The corresponding starlight suppression requirement to detect a planet with planet/star contrast = 6.1×10^(−11) is relaxed by a factor of 10 (100) for HabEx (LUVOIR).
HACC Cosmological Simulations: First Data Release

We describe the first major public data release from cosmological simulations carried out with Argonne's HACC code. This initial release covers a range of datasets from large gravity-only simulations. The data products include halo information for multiple redshifts, down-sampled particles, and lightcone outputs. We provide data from two very large LCDM simulations as well as beyond-LCDM simulations spanning eleven w0-wa cosmologies. Our release platform uses Petrel, a research data service, located at the Argonne Leadership Computing Facility. Petrel offers fast data transfer mechanisms and authentication via Globus, enabling simple and efficient access to stored datasets. Easy browsing of the available data products is provided via a web portal that allows the user to navigate simulation products efficiently. The data hub will be extended by adding more types of data products and by enabling computational capabilities to allow direct interactions with simulation results.
Residually free 3–manifolds

The theory of residually free groups, and in particular fully residually free groups, has been the subject of intense study in recent years, for the most part because of the important role that finitely generated fully residually free groups (also known as limit groups) play in the logic of free groups (see Sela [20] et seq and Kharlampovich and Myasnikov [11; 12] et seq). A group G is residually free if for each nontrivial element g there is a homomorphism f from G to a free group so that f .g/ is nontrivial; it is fully residually free if the same holds when the element g is replaced by a finite set of nontrivial elements. The simplest examples of residually free groups, aside from free groups and free abelian groups, are the fundamental groups of (most) compact surfaces.
Extended Radio Structures and a Compact X-Ray Cool-core in the Cluster Source PKS 1353–341

We present a radio and X-ray study of PKS 1353-341, the brightest cluster galaxy radio source at the center of a recent Chandra-discovered X-ray cluster. Our multi-frequency VLA images reveal an edge-brightened (FR-II), double-lobed structure with total ~50 kpc extent and 1.5 GHz power of $1.2\times10^{25}$ W Hz$^{-1}$, separated from the bright, arcsecond-scale core. We reanalyzed the Chandra data and found the X-ray emitting AGN is offset by ~9 kpc from a compact X-ray cool-core with temperature, $kT=3.1\pm0.5$ keV, and a radius of ~22 kpc, surrounded by a hotter $kT=6.3\pm0.7$ keV gas out to ~50 kpc. The offset suggests sloshing inside the cool-core induced by a minor merger or a past outburst of the AGN that produced the large-scale radio lobes. The comparable spatial scales of the lobes with the interface between the different temperature X-ray plasma indicate the lobes are actively heating the outer layers of what is now a remnant compact cool-core. Our dual-frequency VLBA images reveal substructure in the central radio source, consisting of a radio core with double-sided pc-scale jets pointing toward the kpc-scale structures. The northern jet is detected only at 8.4 GHz, indicating its emission is behind an absorbing torus or disk. We also measured faster apparent motions in the southern jet up to $1.9\pm1.1c$ than in the northern jet ($0.8\pm0.5c$). While the VLBA observations indicate the southern jet is aligned slightly closer to our line of sight, the asymmetries are overall modest and imply minimal projection effects in the large-scale radio structures.
Differential Harnack estimates for Fisher’s equation

In this paper, we derive several differential Harnack estimates (also known as Li-Yau-Hamilton-type estimates) for positive solutions of Fisher's equation. We use the estimates to obtain lower bounds on the speed of traveling wave solutions and to construct classical Harnack inequalities.
No radial excitations in low energy QCD. II. The shrinking radius of hadrons

We discuss the implications of our prior results obtained in our companion paper (Eur. Phys. J. C (2013). doi:10.1140/epjc/s10052-013-2298-9). Inescapably, they lead to three laws governing the size of hadrons, including in particular protons and neutrons that make up the bulk of ordinary matter: (a) there are no radial excitations in low-energy QCD; (b) the size of a hadron is largest in its ground state; (c) the hadron’s size shrinks when its orbital excitation increases. The second and third laws follow from the first law. It follows that the path from confinement to asymptotic freedom is a Regge trajectory. It also follows that the top quark is a free, albeit short-lived, quark.
MinneApple: A Benchmark Dataset for Apple Detection and Segmentation

In this work, we present a new dataset to advance the state-of-the-art in fruit detection, segmentation, and counting in orchard environments. While there has been significant recent interest in solving these problems, the lack of a unified dataset has made it difficult to compare results. We hope to enable direct comparisons by providing a large variety of high-resolution images acquired in orchards, together with human annotations of the fruit on trees. The fruits are labeled using polygonal masks for each object instance to aid in precise object detection, localization, and segmentation. Additionally, we provide data for patch-based counting of clustered fruits. Our dataset contains over 41’0000 annotated object instances in 1000 images. We present a detailed overview of the dataset together with baseline performance analysis for bounding box detection, segmentation, and fruit counting as well as representative results for yield estimation. We make this dataset publicly available and host a CodaLab challenge to encourage a comparison of results on a common dataset. To download the data and learn more about the MinneApple dataset, please see the project website: http://rsn.cs.umn.edu/index.php/MinneApple . Up to date information is available online.
A proof of Pieri’s formula using the generalized Schensted insertion algorithm for rc-graphs

We provide a generalization of the Schensted insertion algorithm for rc-graphs of Bergeron and Billey. The new algorithm is used to give a new proof of Pieri's formula.
Salienteye: Maximizing Engagement While Maintaining Artistic Style on Instagram Using Deep Neural Networks

Instagram has become a great venue for amateur and professional photographers alike to showcase their work. It has, in other words, democratized photography. Generally, photographers take thousands of photos in a session, from which they pick a few to showcase their work on Instagram. Photographers trying to build a reputation on Instagram have to strike a balance between maximizing their followers' engagement with their photos, while also maintaining their artistic style. We used transfer learning to adapt Xception, which is a model for object recognition trained on the ImageNet dataset, to the task of engagement prediction and utilized Gram matrices generated from VGG19, another object recognition model trained on ImageNet, for the task of style similarity measurement on photos posted on Instagram. Our models can be trained on individual Instagram accounts to create personalized engagement prediction and style similarity models. Once trained on their accounts, users can have new photos sorted based on predicted engagement and style similarity to their previous work, thus enabling them to upload photos that not only have the potential to maximize engagement from their followers but also maintain their style of photography. We trained and validated our models on several Instagram accounts, showing it to be adept at both tasks, also outperforming several baseline models and human annotators.
Coherent phenomena in terahertz 2D plasmonic structures: strong coupling, plasmonic crystals, and induced transparency by coupling of localized modes

The device applications of plasmonic systems such as graphene and two dimensional electron gases (2DEGs) in III-V heterostructures include terahertz detectors, mixers, oscillators and modulators. These two dimensional (2D) plasmonic systems are not only well-suited for device integration, but also enable the broad tunability of underdamped plasma excitations via an applied electric field. We present demonstrations of the coherent coupling of multiple voltage tuned GaAs/AlGaAs 2D plasmonic resonators under terahertz irradiation. By utilizing a plasmonic homodyne mixing mechanism to downconvert the near field of plasma waves to a DC signal, we directly detect the spectrum of coupled plasmonic micro-resonator structures at cryogenic temperatures. The 2DEG in the studied devices can be interpreted as a plasmonic waveguide where multiple gate terminals control the 2DEG kinetic inductance. When the gate tuning of the 2DEG is spatially periodic, a one-dimensional finite plasmonic crystal forms. This results in a subwavelength structure, much like a metamaterial element, that nonetheless Bragg scatters plasma waves from a repeated crystal unit cell. A 50% in situ tuning of the plasmonic crystal band edges is observed. By introducing gate-controlled defects or simply terminating the lattice, localized states arise in the plasmonic crystal. Inherent asymmetries at the finite crystal boundaries produce an induced transparency-like phenomenon due to the coupling of defect modes and crystal surface states known as Tamm states. The demonstrated active control of coupled plasmonic resonators opens previously unexplored avenues for sensitive direct and heterodyne THz detection, planar metamaterials, and slow-light devices.
THE UNIVERSE IS A STRANGE PLACE

Our understanding of ordinary matter is remarkably accurate and complete, but it is based on principles that are very strange and unfamiliar. As I'll explain, we've come to understand matter to be a Music of the Void, in a remarkably literal sense. Just as we physicists finalized that wonderful understanding, towards the end of the twentieth century, astronomers gave us back our humility, by informing us that ordinary matter – what we, and chemists and biologists, and astronomers themselves, have been studying all these centuries constitutes only about 5% of the mass of the universe as a whole. I'll describe some of our promising attempts to rise to this challenge by improving, rather than merely complicating, our description of the world.
Auto-stabilized electron

We include effects of self-gravitation in the self-interaction of single electrons with the electromagnetic field. When the effect of gravitation is included there is an inevitable cut-off of the k...
Bi-Directional Value Learning for Risk-Aware Planning Under Uncertainty

Decision-making under uncertainty is a crucial ability for autonomous systems. In its most general form, this problem can be formulated as a partially observable Markov decision process (POMDP). The solution policy of a POMDP can be implicitly encoded as a value function. In partially observable settings, the value function is typically learned via forward simulation of the system evolution. Focusing on accurate and long-range risk assessment, we propose a novel method, where the value function is learned in different phases via a bi-directional search in belief space. A backward value learning process provides a long-range and risk-aware base policy. A forward value learning process ensures local optimality and updates the policy via forward simulations. We consider a class of scalable and continuous-space rover navigation problems to assess the safety, scalability, and optimality of the proposed algorithm. The results demonstrate the capabilities of the proposed algorithm in evaluating long-range risk/safety of the planner while addressing continuous problems with long planning horizons.