Miracle-dz/UniFAR-FTUs huggingface dataset:
Spin-dependent scattering in a silicon transistor

The scattering of conduction electrons off neutral donors depends sensitively on the relative orientation of their spin states. We present a theory of spin-dependent scattering in the two dimensional electron gas (2DEG) of field effect transistors. Our theory shows that the scattering mechanism is dominated by virtual transitions to negatively ionized donor levels. This effect translates into a source-drain current that always gets reduced when donor spins are at resonance with a strong microwave field. We propose a model for donor impurities interacting with conduction electrons in a silicon transistor, and compare our explicit numerical calculations to electrically detected magnetic resonance (EDMR) experiments. Remarkably, we show that EDMR is optimal for donors placed into a sweet spot located at a narrow depth window quite far from the 2DEG interface. This allows significant optimization of spin signal intensity for the minimal number of donors placed into the sweet spot, enabling the development of single spin readout devices. Our theory reveals an interesting dependence on conduction electron spin polarization p_c. As p_c increases upon spin injection, the EDMR amplitude first increases as p_{c}^{2}, and then saturates when a polarization threshold p_T is reached. These results show that it is possible to use EDMR as an in-situ probe of carrier spin polarization in silicon and other materials with weak spin-orbit coupling.
An interpretation of variational principles for gauge theories: a cyclic coordinate alternative to ADM split

I show that there is an ambiguity in how one treats auxiliary variables in gauge theories including general relativity cast as 3 + 1 geometrodynamics. Auxiliary variables may be treated pre-variationally as multiplier coordinates or as the velocities corresponding to cyclic coordinates. The latter treatment works through the physical meaninglessness of auxiliary variables' values applying also to the end points (or end spatial hypersurfaces) of the variation, so that these are free rather than fixed. (This is also known as variation with natural boundary conditions.) Further principles of dynamics workings such as Routhian reduction and the Dirac procedure are shown to have parallel counterparts for this new formalism. One advantage of the new scheme is that the corresponding actions are more manifestly relational. While the electric potential is usually regarded as a multiplier coordinate and Arnowitt, Deser and Misner have regarded the lapse and shift likewise, this paper's scheme considers new flux, instant and grid variables whose corresponding velocities are, respectively, the above-mentioned previously used variables. This paper's way of thinking about gauge theory furthermore admits interesting generalizations as regards variational principles for the conformal form of general relativity's initial value problem.
A NOVEL APPROACH IN CONSTRAINING ELECTRON SPECTRA IN BLAZAR JETS: THE CASE OF Markarian 421

We report results from the observations of the well-studied TeV blazar Mrk 421 with the Swift and the Suzaku satellites in 2008 December. During the observation, Mrk 421 was found in a relatively low activity state, with the corresponding 2–10 keV flux of 3 × 10−10 erg s−1 cm−2. For the purpose of robustly constraining the UV-to-X-ray emission continuum we selected only the data corresponding to truly simultaneous time intervals between Swift and Suzaku, allowing us to obtain a good-quality, broadband spectrum despite a modest length (0.6 ks) exposure. We analyzed the spectrum with the parametric forward-fitting SYNCHROTRON model implemented in XSPEC assuming two different representations of the underlying electron energy distribution, both well motivated by the current particle acceleration models: a power-law distribution above the minimum energy γmin with an exponential cutoff at the maximum energy γmax, and a modified ultra-relativistic Maxwellian with an equilibrium energy γeq. We found that the latter implies unlikely physical conditions within the blazar zone of Mrk 421. On the other hand, the exponentially moderated power-law electron distribution gives two possible sets of the model parameters: (1) flat spectrum dN′e/dγ ∝ γ−1.91 with low minimum electron energy γmin < 103, and (2) steep spectrum ∝γ−2.77 with high minimum electron energy γmin ≃ 2 × 104. We discuss different interpretations of both possibilities in the context of a diffusive acceleration of electrons at relativistic, sub- or superluminal shocks. We also comment on exactly how the γ-ray data can be used to discriminate between the different proposed scenarios.
Research on prediction of security corresponding frequency based on GRU

In the security analysis of the situational awareness system, the prediction of the frequency of intrusion events has also become an interesting research point. The accumulation of intrusion frequency in the past and the data after manual screening can assist us in establishing an intrusion perception prediction mechanism. At the same time, with the innovation of hardware technology, we can use deep learning GRU technology to improve prediction efficiency and reduce time-consuming. This article uses statistical data on the frequency of past intrusion events, takes 7 days as a time period for training data and forecasts, uses a hidden layer of 60 neurons and an empirical learning rate. Experiments have proved that the prediction effect of GRU can effectively predict the frequency range of events, and it is expected to be deployed in the situational awareness framework.
A laser gyroscope system to detect the gravito-magnetic effect on Earth

Ring lasers are inertial sensors for angular velocity based on the Sagnac effect. In recent years they have reached a very high sensitivity and accuracy; the best performing one, the ring Laser G in Wettzell (Germany), a square ring with 16 m perimeter, has reached a sensitivity of 12prad/s very close to the shot noise limit inferred from ring-down time measurements. On this basis it is expected that an array of six square ring lasers of 36 m perimeter, can perform a 1% accuracy test for the measurement of the Lense-Thirring frame dragging after 2 years of integration time. Essential for this measurement is the comparison between the Earth angular velocity and orientation in space measured with the ring array and compared to the measurement series maintained by the International Earth Rotation and Reference System Service (IERS), which measures Earth Rotation and pole position with respect to remote quasars. It has been shown that the accuracy of G in Wettzell is limited by the low frequency motion of the near surface laboratory, which is of the order of several prad/s, roughly 100 times larger than the Lense-Thirring contribution. For this reason the entire experiment should be placed in a quite underground laboratory, where these perturbations are reduced. The feasibility to properly place such a device inside the GranSasso INFN National Laboratory has been investigated.
The VIMOS Public Extragalactic Redshift Survey (VIPERS): spectral classification through principal component analysis

We develop a Principal Component Analysis aimed at classifying a subset of 27 350 spectra of galaxies in the range 0.4 < z < 1.0 collected by the VIMOS Public Extragalactic Redshift Survey (VIPERS). We apply an iterative algorithm to simultaneously repair parts of spectra affected by noise and/or sky residuals, and reconstruct gaps due to rest-frame transformation, and obtain a set of orthogonal spectral templates that span the diversity of galaxy types. By taking the three most significant components, we find that we can describe the whole sample without contamination from noise. We produce a catalogue of eigencoefficients and template spectra that will be part of future VIPERS data releases. Our templates effectively condense the spectral information into two coefficients that can be related to the age and star formation rate of the galaxies. We examine the spectrophotometric types in this space and identify early, intermediate, late and starburst galaxies.
A four‐pole single passband filter based on planar multilayered closed cavity with three magnetic side walls

A double‐layered substrate three magnetic side wall cavity (TMSWC) and three‐layered configuration with stacked double TMSWCs are proposed. These structures can realize miniaturization by equivalent magnetic walls inside closed cavities and avoid radiation at the same time. Based on the above three‐layered form, a compact four‐pole single passband filter is designed and fabricated. The measured results agree well with the simulated ones.
OPTICAL MONITORING OF 3C 390.3 FROM 1995 TO 2004 AND POSSIBLE PERIODICITIES IN THE HISTORICAL LIGHT CURVE

We report V, R, and I band CCD photometry of the radio galaxy 3C 390.3 obtained with the 1.56 m telescope of the Shanghai Astronomical Observatory from 1995 March to 2004 August. Combining these data with data from the literature, we have constructed a historical light curve from 1894 to 2004 and searched for periodicities using the CLEANest program. We find possible periods of 8.30 ± 1.17, 5.37 ± 0.49, 3.51 ± 0.21, and 2.13 ± 0.08 yr.
Introducing the Online Political Influence Efforts dataset

This article introduces a dataset on the covert use of social media to influence politics by promoting propaganda, advocating controversial viewpoints, and spreading disinformation. Influence efforts (IEs) are defined as: (i) coordinated campaigns by a state, or the ruling party in an autocracy, to impact one or more specific aspects of politics at home or in another state, (ii) through media channels, including social media, by (iii) producing content designed to appear indigenous to the target state. Our data draw on more than 1,000 media reports and 500 research articles/reports to identify IEs, track their progress, and classify their features. The data cover 78 foreign influence efforts (FIEs) and 25 domestic influence efforts (DIEs) – in which governments targeted their own citizens – against 51 different countries from 2011 through early 2021. The Influence Effort dataset measures covert information campaigns by state actors, facilitating research on contemporary statecraft.
Scaling laws and warning signs for bifurcations of SPDEs

Critical transitions (or tipping points) are drastic sudden changes observed in many dynamical systems. Large classes of critical transitions are associated with systems, which drift slowly towards a bifurcation point. In the context of stochastic ordinary differential equations, there are results on growth of variance and autocorrelation before a transition, which can be used as possible warning signs in applications. A similar theory has recently been developed in the simplest setting for stochastic partial differential equations (SPDEs) for self-adjoint operators in the drift term. This setting leads to real discrete spectrum and growth of the covariance operator via a certain scaling law. In this paper, we develop this theory substantially further. We cover the cases of complex eigenvalues, degenerate eigenvalues as well as continuous spectrum. This provides a fairly comprehensive theory for most practical applications of warning signs for SPDE bifurcations.
BENCHMARKING FAST-TO-ALFVÉN MODE CONVERSION IN A COLD MHD PLASMA. II. HOW TO GET ALFVÉN WAVES THROUGH THE SOLAR TRANSITION REGION

Alfvén waves may be difficult to excite at the photosphere due to low-ionization fraction and suffer near-total reflection at the transition region (TR). Yet they are ubiquitous in the corona and heliosphere. To overcome these difficulties, we show that they may instead be generated high in the chromosphere by conversion from reflecting fast magnetohydrodynamic waves, and that Alfvénic TR reflection is greatly reduced if the fast reflection point is within a few scale heights of the TR. The influence of mode conversion on the phase of the reflected fast wave is also explored. This phase can potentially be misinterpreted as a travel speed perturbation with implications for the practical seismic probing of active regions.
DIVERSITY OF LUMINOUS SUPERNOVAE FROM NON-STEADY MASS LOSS

We show that the diversity in the density slope of the dense wind due to non-steady mass loss can be one way to explain the spectral diversity of Type II luminous supernovae (LSNe). The interaction of SN ejecta and wind surrounding it is considered to be a power source to illuminate LSNe because many LSNe show the wind signature in their spectra (Type IIn LSNe). However, there also exist LSNe without the spectral features caused by the wind (Type IIL LSNe). We show that, even if LSNe are illuminated by the interaction, it is possible that they do not show the narrow spectra from the wind if we take into account the non-steady mass loss of their progenitors. When the shock breakout takes place in a dense wind with the density structure ρ∝r−w, the ratio of the diffusion timescale in the optically thick region of the wind (td) and the shock propagation timescale of the entire wind after the shock breakout (ts) strongly depends on w. For the case w ≲ 1, both timescales are comparable (td/ts ≃ 1) and td/ts gets smaller as w gets larger. For the case td/ts ≃ 1, the shock goes through the entire wind just after the light-curve (LC) peak, and narrow spectral lines from the wind cannot be observed after the LC peak (Type IIL LSNe). If td/ts is much smaller, the shock wave continues to propagate in the wind after the LC peak, and unshocked wind remains (Type IIn LSNe). This difference can be obtained only through careful treatment of the shock breakout condition in a dense wind. The lack of narrow Lorentzian line profiles in Type IIL LSNe before the LC peak can also be explained by the difference in the density slope. Furthermore, we apply our model to Type IIn LSN 2006gy and Type IIL LSN 2008es and find that our model is consistent with the observations.
Neutrino mass, dark energy, and the linear growth factor

We study the degeneracies between neutrino mass and dark energy as they manifest themselves in cosmological observations. In contradiction to a popular formula in the literature, the suppression of the matter power spectrum caused by massive neutrinos is not just a function of the ratio of neutrino to total mass densities ${f}_{\ensuremath{\nu}}={\ensuremath{\Omega}}_{\ensuremath{\nu}}/{\ensuremath{\Omega}}_{m}$, but also each of the densities independently. We also present a fitting formula for the logarithmic growth factor of perturbations in a flat universe, $f(z,k;{f}_{\ensuremath{\nu}},w,{\ensuremath{\Omega}}_{\mathrm{DE}})\ensuremath{\approx}[1\ensuremath{-}A(k){\ensuremath{\Omega}}_{\mathrm{DE}}{f}_{\ensuremath{\nu}}+B(k){f}_{\ensuremath{\nu}}^{2}\ensuremath{-}C(k){f}_{\ensuremath{\nu}}^{3}]{\ensuremath{\Omega}}_{m}^{\ensuremath{\alpha}}(z)$, where $\ensuremath{\alpha}$ depends on the dark energy equation of state parameter $w$. We then discuss cosmological probes where the $f$ factor directly appears: peculiar velocities, redshift distortion, and the integrated Sachs-Wolfe effect. We also modify the approximation of Eisenstein and Hu [Astrophys. J. 511, 5 (1999)] for the power spectrum of fluctuations in the presence of massive neutrinos and provide a revised code [http://www.star. ucl.ac. uk/~lahav/nu_matter_power. f].
Construction of a relativistic Ornstein-Uhlenbeck process

Based on a version of Dudley's Wiener process on the mass shell in the momentum Minkowski space of a massive point particle, a model of a relativistic Ornstein--Uhlenbeck process is constructed by addition of a specific drift term. The invariant distribution of this momentum process as well as other associated processes are computed.
A Quantitative Approach and an Open-Source Tool for Social Impacts Assessment

Social impact analysis urgently needs attention in various sectors due to its critical roles in enhancing sustainability benefits. Properly assessing social impacts requires a consistent set of guidelines and requirements to reduce the practitioners’ bias. Life cycle assessment (LCA) is a widely recognized method that can be utilized to quantitatively assess three dimensions of sustainable development in an integrated manner. This study proposes an open-source tool for social impact analysis, that particularly evaluates work environment health impacts, following the LCA-defined principles, framework, requirements, and guidelines for sustainability assessment. The proposed tool in this study can quantify the social impacts and determine the categories that are being affected either negatively or positively. In addition, this study provides an overview of the existing social impact assessment approaches, identifies the critical challenges of the current techniques, and highlights opportunities for continued research to achieve more effective solutions. As of yet, a reliable and open-source tool has not been achieved to help decision-makers in both academia and industry. Thus, we developed a web-based tool for assessing social impacts in eight domains by allowing the use of multiple metrics and comparing two processes.
Dirac matrices for Chern-Simons gravity

A genuine gauge theory for the Poincare, de Sitter or anti-de Sitter algebras can be constructed in (2n − 1)-dimensional spacetime by means of the Chern-Simons form, yielding a gravitational theory that differs from General Relativity but shares many of its properties, such as second order field equations for the metric. The particular form of the Lagrangian is determined by a rank n, symmetric tensor invariant under the relevant algebra. In practice, the calculation of this invariant tensor can be reduced to the computation of the trace of the symmetrized product of n Dirac Gamma matrices Γab in 2n-dimensional spacetime. While straightforward in principle, this calculation can become extremely cumbersome in practice. For large enough n, existing computer algebra packages take an inordinate long time to produce the answer or plainly fail having used up all available memory. In this talk we show that the general formula for the trace of the symmetrized product of 2n Gamma matrices Γab can be written as a c.
Role of Anticoagulants for Stroke Prevention in Low-Risk Population Having Atrial Fibrillation and Chronic Kidney Disease: A Systematic Review

Over the last few years, there has been a rising incidence of atrial fibrillation and chronic kidney disease cases. Stroke is the major complication seen in such patients. The combination of both diseases makes patient management more tedious. PubMed and Google Scholar underwent screening with keywords and a Medical Subject Heading (MeSH) combination. The words were “atrial fibrillation,” “chronic kidney disease/chronic renal insufficiency,” “anticoagulation,” “efficacy,” and “left atrial appendage occlusion. ” Articles had screening and appraisal. With the English language as a filter, papers from 2002 to 2022 are part of this review. We reviewed studies including male patients with atrial fibrillation and chronic kidney disease under 65 years to see their risk-benefit from anticoagulation. In addition, left atrial appendage occlusion (LAAO) is also compared. A total of eight articles are part of this systematic review. Age plays a more prominent role than gender regarding the impact of drugs on stroke prevention. LAAO also shows a better outcome than oral anticoagulation, provided people agree to undergo surgery. More studies must be done for this target population, especially comparing results with LAAO and oral anticoagulation.
DO HOT HALOS AROUND GALAXIES CONTAIN THE MISSING BARYONS?

Galaxies are missing most of their baryons, and many models predict these baryons lie in a hot halo around galaxies. We establish observationally motivated constraints on the mass and radii of these halos using a variety of independent arguments. First, the observed dispersion measure of pulsars in the Large Magellanic Cloud allows us to constrain the hot halo around the Milky Way: if it obeys the standard Navarro, Frenk, and White (NFW) profile, it must contain less than 4%–5% of the missing baryons from the Galaxy. This is similar to other upper limits on the Galactic hot halo, such as the soft X-ray background and the pressure around high-velocity clouds. Second, we note that the X-ray surface brightness of hot halos with NFW profiles around large isolated galaxies is high enough that such emission should be observed, unless their halos contain less than 10%–25% of their missing baryons. Third, we place constraints on the column density of hot halos using nondetections of O vii absorption along active galactic nucleus (AGN) sightlines: in general they must contain less than 70% of the missing baryons or extend to no more than 40 kpc. Flattening the density profile of galactic hot halos weakens the surface brightness constraint so that a typical L* galaxy may hold half its missing baryons in its halo, but the O vii constraint remains unchanged, and around the Milky Way a flattened profile may only hold 6%–13% of the missing baryons from the Galaxy ((2–4) × 1010 M☉). We also show that AGN and supernovae at low to moderate redshift—the theoretical sources of winds responsible for driving out the missing baryons—do not produce the expected correlations with the baryonic Tully–Fisher relationship and, therefore, are insufficient to explain the missing baryons from galaxies. We conclude that most of missing baryons from galaxies do not lie in hot halos around the galaxies, and that the missing baryons never fell into the potential wells of protogalaxies in the first place. They may have been expelled from the galaxies as part of the process of galaxy formation.
NEAR- AND FAR-FIELD RESPONSE TO COMPACT ACOUSTIC SOURCES IN STRATIFIED CONVECTION ZONES

The role of the acoustic continuum associated with compact sources in the Sun's interior wave field is explored for a simple polytropic model. The continuum produces a near-field acoustic structure—the so-called acoustic jacket—that cannot be represented by a superposition of discrete normal modes. Particular attention is paid to monochromatic point sources of various frequency and depth, and to the surface velocity power that results, both in the discrete f- and p-mode spectrum and in the continuum. It is shown that a major effect of the continuum is to heal the surface wave field produced by compact sources, and therefore to hide them from view. It is found that the continuous spectrum is not a significant contributor to observable inter-ridge seismic power.
Wave function of Vasiliev's universe: A few slices thereof

We study the partition function of the free Sp(N) conformal field theory recently conjectured to be dual to asymptotically de Sitter higher-spin gravity in four-dimensions. We compute the partition function of this CFT on a round sphere as a function of a finite mass deformation, on a squashed sphere as a function of the squashing parameter, and on an S2xS1 geometry as a function of the relative size of S2 and S1. We find that the partition function is divergent at large negative mass in the first case, and for small $S^1$ in the third case. It is globally peaked at zero squashing in the second case. Through the duality this partition function contains information about the wave function of the universe. We show that the divergence at small S1 occurs also in Einstein gravity if certain complex solutions are included, but the divergence in the mass parameter is new. We suggest an interpretation for this divergence as indicating an instability of de Sitter space in higher spin gravity, consistent with general arguments that de Sitter space cannot be stable in quantum gravity.