Miracle-dz/UniFAR-FTUs huggingface dataset:
General treatment of quantum and classical spinning particles in external fields

We develop the general theory of spinning particles with electric and magnetic dipole moments moving in arbitrary electromagnetic, inertial and gravitational fields. Both the quantum-mechanical and classical dynamics is investigated. We start from the covariant Dirac equation extended to a spin-${\frac 12}$ fermion with anomalous magnetic and electric dipole moments and then perform the relativistic Foldy-Wouthuysen transformation. This transformation allows us to obtain the quantum-mechanical equations of motion for the physical operators in the Schr\"odinger form and to establish the classical limit of relativistic quantum mechanics. The results obtained are then compared to the general classical description of the spinning particle interacting with electromagnetic, inertial and gravitational fields. The complete agreement between the quantum mechanics and the classical theory is proven in the general case. As an application of the results obtained, we consider the dynamics of a spinning particle in a gravitational wave and analyze the prospects of using the magnetic resonance setup to find possible manifestations of the gravitational wave on spin.
Gravitational waves from warm inflation

A fundamental prediction of inflation is a nearly scale-invariant spectrum of gravitational wave. The features of such a signal provide extremely important information about the physics of the early universe. In this paper, we focus on several topics about warm inflation. First, we discuss the stability property about warm inflation based on nonequilibrium statistical mechanics, which gives more fundamental physical illustrations to thermal property of such model. Then, we calculate the power spectrum of gravitational waves generated during warm inflation, in which there are three components contributing to such spectrum: thermal term, quantum term and cross term combining the both. We also discuss some interesting properties about these terms and illustrate them in different panels. As a model different from cold inflation, warm inflation model has its individual properties in observational practice, so we finally give a discussion about the observational effect to distinguish it from cold inflation.
Lorentz invariance in shape dynamics

Shape dynamics is a reframing of canonical general relativity in which time reparametrization invariance is ‘traded’ for a local conformal invariance. We explore the emergence of Lorentz invariance in this model in three contexts: as a maximal symmetry, an asymptotic symmetry and a local invariance.
THE ORBITAL PERIOD OF SCORPIUS X-1

The orbital period of Sco X-1 was first identified by Gottlieb et al. While this has been confirmed on multiple occasions, this work, based on nearly a century of photographic data, has remained the reference in defining the system ephemeris ever since. It was, however, called into question when Vanderlinde et al. claimed to find the one-year alias of the historical period in RXTE/All-Sky Monitor data and suggested that this was the true period rather than that of Gottlieb et al. We examine data from the All Sky Automated Survey (ASAS) spanning 2001–2009. We confirm that the period of Gottlieb et al. is in fact the correct one, at least in the optical, with the one-year alias strongly rejected by these data. We also provide a modern time of minimum light based on the ASAS data.
SPITZER/IRAC LOW SURFACE BRIGHTNESS OBSERVATIONS OF THE VIRGO CLUSTER

We present 3.6 and 4.5 μm Spitzer Infrared Array Camera (IRAC) imaging over 0.77 deg2 at the Virgo cluster core for the purpose of understanding the formation mechanisms of the low surface brightness intracluster light (ICL) features. Instrumental and astrophysical backgrounds that are hundreds of times higher than the signal were carefully characterized and removed. We examine ICL plumes as well as the outer halo of the giant elliptical M87. For two ICL plumes, we use optical colors to constrain their ages to be greater than 3 and 5 Gyr, respectively. Upper limits on the IRAC fluxes constrain the upper limits to the masses, and optical detections constrain the lower limits to the masses. In this first measurement of mass of ICL plumes we find masses in the range of 5.5 × 108 − 4.5 × 109 and 2.1 × 108–1.5 × 109 M☉ for the two plumes for which we have coverage. Given their expected short lifetimes, and a constant production rate for these types of streams, integrated over Virgo's lifetime, they can account for the total ICL content of the cluster, implying that we do not need to invoke ICL formation mechanisms other than gravitational mechanisms leading to bright plumes. We also examined the outer halo of the giant elliptical M87. The color profile from the inner to outer halo of M87 (160 kpc) is consistent with either a flat or optically blue gradient, where a blue gradient could be due to younger or lower metallicity stars at larger radii. The similarity of the age predicted by both the infrared and optical colors (> a few gigayears) indicates that the optical measurements are not strongly affected by dust extinction.
PROGRESSIVE STAR FORMATION IN THE YOUNG GALACTIC SUPER STAR CLUSTER NGC 3603

Early Release Science observations of the cluster NGC 3603 with the WFC3 on the refurbished Hubble Space Telescope allow us to study its recent star formation history. Our analysis focuses on stars with Hα excess emission, a robust indicator of their pre-main sequence (PMS) accreting status. The comparison with theoretical PMS isochrones shows that 2/3 of the objects with Hα excess emission have ages from 1 to 10 Myr, with a median value of 3 Myr, while a surprising 1/3 of them are older than 10 Myr. The study of the spatial distribution of these PMS stars allows us to confirm their cluster membership and to statistically separate them from field stars. This result establishes unambiguously for the first time that star formation in and around the cluster has been ongoing for at least 10–20 Myr, at an apparently increasing rate.
What produces the far-infrared/submillimetre emission in the most luminous QSOs?

The AGN. I examine the average spectral energy distributions (SEDs) of two samples of the most powerful, unobscured quasi-stellar objects (QSOs) at 2 < z < 3.5, with rest-frame optical luminosities in the range of 46.2 < log νLν (5100 A) < 47.4, corresponding to the tail of the 2 < z < 4 QSO optical luminosity function. I find that the active galactic nucleus (AGN) could potentially account for the entire broad-band emission from the ultraviolet to the submillimetre (submm), on the basis that the SEDs of these sources are similar to the intrinsic AGN SEDs derived for lower power, lower redshift QSOs. Although this does not preclude substantial star formation in their host galaxies, I find that the AGN dominates the total infrared (IR) luminosity, removing the necessity for a star-forming component in the far-IR/submm. I argue that the origin of the far-IR/submm emission in such powerful QSOs includes a small contribution from the AGN torus but is predominantly linked to dust at kpc-scales heated by the AGN. The latter component accounts for at least 5–10 per cent of the bolometric AGN luminosity and has an implied dust mass of the order of 108 M⊙.
An effective theory of metrics with maximal proper acceleration

A geometric theory for spacetimes whose world lines associated with physical particles have an upper bound for the proper acceleration is developed. After some fundamental remarks on the requirements that the classical dynamics for point particles should hold, the notion of a generalized metric and a theory of maximal proper acceleration are introduced. A perturbative approach to metrics of maximal proper acceleration is discussed and we show how it provides a consistent theory where the associated Lorentzian metric corresponds to the limit when the maximal proper acceleration goes to infinity. Then several of the physical and kinematical properties of the maximal acceleration metric are investigated, including a discussion of the rudiments of the causal theory and the introduction of the notions of radar distance and celerity function. We discuss the corresponding modification of the Einstein mass-energy relation when the associated Lorentzian geometry is flat. In such a context it is also proved that the physical dispersion relation is relativistic. Two possible physical scenarios where the modified mass–energy relation could be confronted against the experiment are briefly discussed.
From Mud: Lessons of Mindfulness Found in Clay Work From Mud: Lessons of Mindfulness Found in Clay Work

A significant part of the earth's history, clay represents the interconnectedness of all life. While clay has long been used in the field of art therapy, the use of the material in mindfulness has been unfolding. This creative thesis explores the significance of clay to humankind. It reviews Buddhist literature and text to identify the elements and parallels of clay work that make it a compelling contemplative material. Neuroscientific research that connects the mind and body interaction further make the case for clay work as an effective mindfulness-based practice. The creative component of this thesis is a clay retreat that offered a variety of contemplative practices centered around clay work. Practices included pinching clay and breathwork, R.A.I.N method inspired by Tara Brach, mindful walking and a Metta meditation. Each practice invited the clay as a companion or an anchor. The knowledge and skills may serve as a guide to other practitioners who seek to incorporate clay to their practice of mindfulness.
RELAXATION TIME AND DISSIPATION INTERACTION IN HOT PLANET ATMOSPHERIC FLOW SIMULATIONS

We elucidate the interplay between Newtonian thermal relaxation and numerical dissipation, of several different origins, in flow simulations of hot extrasolar planet atmospheres. Currently, a large range of Newtonian relaxation, or “cooling,” times (∼10 days to ∼1 hr) is used among different models and within a single model over the model domain. In this study, we demonstrate that a short relaxation time (much less than the planetary rotation time) leads to a large amount of unphysical, grid-scale oscillations that contaminate the flow field. These oscillations force the use of an excessive amount of artificial viscosity to quench them and prevent the simulation from “blowing up. ” Even if the blow-up is prevented, such simulations can be highly inaccurate because they are either severely overdissipated or underdissipated, and are best discarded in these cases. Other numerical stability and time step size enhancers (e.g., Robert–Asselin filter or semi-implicit time-marching schemes) also produce similar, but less excessive, damping. We present diagnostics procedures to choose the “optimal” simulation and discuss implications of our findings for modeling hot extrasolar planet atmospheres.
DETECTION OF TWO CARBON-CHAIN-RICH CORES: CB130-3 AND L673-SMM4

We have found two dense cores, CB130-3 and L673-SMM4, where the carbon-chain molecules are extremely abundant relative to NH3, during a survey observation of radio emission lines of CCS, HC3N, HC5N, and NH3 toward dark cloud cores. Judging from the low NH3/CCS ratios, they are possible candidates for “Carbon-Chain-Producing Regions” (CCPRs) recognized as chemically young dark cloud cores. The deuterium fractionation ratios DNC/HN13C in CB130-3 and L673-SMM4 are found to be 1.28+0.27−0.05 and 1.96+0.32−0.01, respectively, which are comparable to or slightly higher than those in CCPRs found previously. We suggest that the dense cores of CB130-3 and L673-SMM4 are analogous to CCPRs, but their chemical evolutionary phase would be slightly older than those of the dense cores in the Taurus region.
An Equalization Current Ripple Cancellation (ECRC) Converter-Based Centralized Equalization System for Series-Connected Battery Strings

Battery equalization management is a key technology to ensure the high-performance and safe operation of electrified transportation such as electric vehicles and electric aircraft. In this article, an equalization current ripple cancellation (ECRC) converter for centralized equalization system is presented. Compared with traditional methods, the ECRC converter-based equalization system achieves a zero-ripple equalization current, so that the unfavorable influence of larger current pulsation on battery cells is eliminated. Meanwhile, under a phase-shifted PWM modulation strategy, the ECRC converter not only implements zero-voltage switching (ZVS) of all switches to reduce switching loss, but also decreases the peak current of the transformer to reduce transformer loss, so that the efficiency of the equalization system is significantly improved. Besides, the value of each power element in the converter is comparatively small, which is conducive to improving the power density of the centralized equalization system. To confirm the theory analysis, an experimental prototype based on a battery string containing 13 cells is built for experimental verification, and a systematic comparison is implemented with existing centralized equalization methods. The experimental and comparison results verify the design of the proposed equalization system and reflect the obvious performance improvement over traditional methods.
Spinning swimming of Volvox by tangential helical wave

The swimming of a sphere by means of tangential helical waves running along its surface is studied on the basis of the Stokes equations. Two types of tangential waves are found. The first of these is associated with a pressure disturbance and leads to a higher rate of net rotation than the second one for the same power. It is suggested that the helical waves are relevant for the rotational swimming of Volvox.
BINARY–DISK INTERACTION: GAP-OPENING CRITERIA

We study the interaction of an equal mass binary with an isothermal circumbinary disk motivated by the evidence of the formation of massive black hole binaries surrounded by gas, after a major merger of gas-rich galaxies. We focus on the torques that the binary produces on the disk and how the exchange of angular momentum can drive the gap formation on it. We propose that the angular momentum exchange between the binary and the disk is through the gravitational interaction of the binary and a (tidally formed) global non-axisymmetric perturbation in the disk. Using this interaction, we derive an analytic criterion for the gap formation in the disk that can be expressed either via the characteristic velocities of the binary-disk system or in terms of the structural parameters h/a and M(< r)/Mbin. Using numerical simulations we show that the simulations where the binary opens a gap in the disk and the simulations where the disk does not have a gap are distributed into two well separated regions. Our analytic criterion predicts a shape of the threshold between these two regions that is consistent with our simulations and the other ones in the literature. We propose an analogy between the regime without (with) a gap in the disk and the Type I (Type II) migration that is observed in simulations of planet–disk interaction (extreme mass ratio binary), emphasizing that the interaction that drives the formation of a gap on the disk is different in the regime that we analyze (comparable mass binary).
Anomalous Transport in Sketched Nanostructures at the LaAlO3/SrTiO3 Interface

The oxide heterostructure LaAlO3/SrTiO3 supports a two-dimensional electron liquid with a variety of competing phases including magnetism, superconductivity and weak antilocalization due to Rashba spin-orbit coupling. Further confinement of this 2D electron liquid to the quasi-one-dimensional regime can provide insight into the underlying physics of this system and reveal new behavior. Here we describe magnetotransport experiments on narrow LaAlO3/SrTiO3 structures created by a conductive atomic force microscope lithography technique. Four-terminal local transport measurements on ~10-nm-wide Hall bar structures yield longitudinal resistances that are comparable to the resistance quantum h/e2 and independent of the channel length. Large nonlocal resistances (as large as 10^4 ohms) are observed in some but not all structures with separations between current and voltage that are large compared to the 2D mean-free path. The nonlocal transport is strongly suppressed by the onset of superconductivity below ~200 mK. The origin of these anomalous transport signatures is not understood, but may arise from coherent transport defined by strong spin-orbit coupling and/or magnetic interactions.
Quantification of a propagating spin-wave packet created by an ultrashort laser pulse in a thin film of a magnetic metal

Coherent spin-wave generation by focused ultrashort laser pulse irradiation was investigated for a permalloy thin film at micrometer scale using an all-optical space and time-resolved magneto-optical Kerr effect. The spin-wave packet propagating perpendicular to magnetization direction was clearly observed, however that propagating parallel to the magnetization direction was not observed. The propagation length, group velocity, center frequency, and packet-width of the observed spin-wave packet were evaluated and quantitatively explained in terms of the propagation of a magneto-static spin-wave driven by ultrafast change of an out-of-plane demagnetization field induced by the focused-pulse laser.
The rise and fall of a challenger: the Bullet Cluster in Λ cold dark matter simulations

The Bullet Cluster has provided some of the best evidence for the Cold Dark Matter (CDM) model via direct empirical proof of the existence of collisionless dark matter, while posing a serious challenge owing to the unusually high inferred pairwise velocities of its progenitor clusters. Here we investigate the probability of nding such a highvelocity pair in large-volume N-body simulations, particularly focusing on dierences between halo nding algorithms. We nd that algorithms that do not account for the kinematics of infalling groups yield vastly dierent statistics and probabilities. When employing the Rockstar halo nder that considers particle velocities, we nd numerous Bullet-like pair candidates that closely match not only the high pairwise velocity, but also the mass, mass ratio, separation distance, and collision angle of the initial conditions that have been shown to produce the Bullet Cluster in non-cosmological hydrodynamic simulations. The probability of nding a massive, high pairwise velocity pair among halos with Mhalo > 10 14 M is 4:6 10 4 using Rockstar, while it is 45 lower using a friends-of-friends (FOF) based approach as in previous studies. This is because the typical spatial extent of Bullet progenitors is such that FOF tends to group them into a single halo despite clearly distinct kinematics. Further requiring an appropriately high average mass among the two progenitors, we nd the number density of Bullet-like candidates to be 3:2 10 10 h 3 Mpc 3 . Our ndings suggest that CDM straightforwardly produces massive, high relative velocity halo pairs analogous to Bullet Cluster progenitors, and hence the Bullet Cluster does not present a challenge to the CDM model.
Compact optical phased array using a serial grating antenna design

We propose an on-chip Si photonics optical phased array based on a serial grating design which eliminates the use of directional couplers in previous designs. It significantly reduces overall phased array size especially when the number of the antenna is small which is often demanded in practice. The simulation results show our design reduces overall phased array size, increases optical power utilization while maintains comparable far field performance.
THE FERMI HAZE: A GAMMA-RAY COUNTERPART TO THE MICROWAVE HAZE

The Fermi Gamma-ray Space Telescope reveals a diffuse inverse Compton (IC) signal in the inner Galaxy with a similar spatial morphology to the microwave haze observed by WMAP, supporting the synchrotron interpretation of the microwave signal. Using spatial templates, we regress out π0 gammas, as well as IC and bremsstrahlung components associated with known soft-synchrotron counterparts. We find a significant gamma-ray excess toward the Galactic center with a spectrum that is significantly harder than other sky components and is most consistent with IC from a hard population of electrons. The morphology and spectrum are consistent with it being the IC counterpart to the electrons which generate the microwave haze seen at WMAP frequencies. In addition, the implied electron spectrum is hard; electrons accelerated in supernova shocks in the disk which then diffuse a few kpc to the haze region would have a softer spectrum. We describe the full-sky Fermi maps used in this analysis and make them available for download.
Supervised Spatial Regionalization using the Karhunen-Loève Expansion and Minimum Spanning Trees

The article presents a methodology for supervised regionalization of data on a spatial domain. Defining a spatial process at multiple scales leads to the famous ecological fallacy problem. Here, we use the ecological fallacy as the basis for a minimization criterion to obtain the intended regions. The Karhunen-Loève Expansion of the spatial process maintains the relationship between the realizations from multiple resolutions. Specifically, we use the Karhunen-Loève Expansion to define the regionalization error so that the ecological fallacy is minimized. The contiguous regionalization is done using the minimum spanning tree formed from the spatial locations and the data. Then, regionalization becomes similar to pruning edges from the minimum spanning tree. The methodology is demonstrated using simulated and real data examples.
Using Isomorphic Problems to Learn Introductory Physics

In this study, we examine introductory physics students' ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. Three hundred and sixty two students from a calculus-based and an algebra-based introductory physics course were given a quiz in the recitation in which they had to first learn from a solved problem provided and take advantage of what they learned from it to solve another problem (which we call the quiz problem) which was isomorphic. Previous research suggests that the multiple-concept quiz problem is challenging for introductory students. Students in different recitation classes received different interventions in order to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. We also conducted think-aloud interviews with four introductory students in order to understand in-depth the difficulties they had and explore strategies to provide better scaffolding. We found that most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem. However, they were not necessarily able to apply the principles correctly. Research suggests that more scaffolding is needed to help students in applying these principles appropriately. We outline a few possible strategies for future investigation.