ShantanuT01/DACTYL-Pretraining huggingface dataset:
(Abridged) In this paper, we use the Tuffs et al. attenuation - inclination models in ultraviolet (UV), optical, and near-infrared (NIR) bands to investigate the average global dust properties in galaxies as a function of stellar mass $M_{*}$, stellar mass surface density $\mu_{*}$, star-formation rate $SFR$, specific star-formation rate $sSFR$, star-formation main-sequence offset $dMS$, and star-formation rate surface density $\Sigma_{SFR}$ at redshifts $z \sim 0$ and $z \sim 0.7$. We use star-forming galaxies from SDSS ($\sim$ 20000) and GAMA ($\sim$ 2000) to form our low-z sample at $0.04 < z < 0.1$ and star-forming galaxies from COSMOS ($\sim$ 2000) for the sample at $0.6 <z < 0.8$. We find that galaxies at $z \sim 0.7$ have higher optical depth $\tau_{B}^{f}$ and clumpiness $F$ than galaxies at $z \sim 0$. The increase in $F$ hints that the stars of $z \sim 0.7$ galaxies are less likely to escape their birth cloud, which might indicate that the birth clouds are larger. We also found that $\tau_{B}^{f}$ increases with $M_{*}$ and $\mu_{*}$independent of sample and therefore redshift. We found no clear trends in $\tau_{B}^{f}$ or $F$ with $SFR$, which could imply that the dust mass distribution is independent of $SFR$. In turn, this would imply that the balance of dust formation and destruction is independent of the $SFR$. Based on an analysis of the inclination-dependence of the Balmer decrement, we find that reproducing the Balmer line emission requires not only a completely optically thick dust component associated with star forming regions, as in the standard Tuffs et al. model, but an extra component of optically thin dust within the birth clouds. This new component implies the existence of dust inside HII regions that attenuates the Balmer emission before it escapes through gaps in the birth cloud and we find it is more important in high-mass galaxies.
We report on a magneto-photoluminescence study of isotopically pure 70Ge/Si self-assembled type-II quantum dots. Oscillatory behaviors attributed to the Aharonov-Bohm effect are simultaneously observed for the emission energy and intensity of excitons subject to an increasing magnetic field. When the magnetic flux penetrates through the ring-like trajectory of an electron moving around each quantum dot, the ground state of an exciton experiences a change in its angular momentum. Our results provide the experimental evidence for the phase coherence of a localized electron wave function in group-IV Ge/Si self-assembled quantum structures.
We study systems of reaction-diffusion equations with discontinuous spatially distributed hysteresis in the right-hand side. The input of hysteresis is given by a vector-valued function of space and time. Such systems describe hysteretic interaction of non-diffusive (bacteria, cells, etc.) and diffusive (nutrient, proteins, etc.) substances leading to formation of spatial patterns. We provide sufficient conditions under which the problem is well posed in spite of the discontinuity of hysteresis. These conditions are formulated in terms of geometry of manifolds defining hysteresis thresholds and the graph of initial data.
In a polar space, embeddable into a projective space, we fix a subspace, that is contained in some hyperplane. The complement of that subspace resembles a slit space or a semiaffine space. We prove that under some assumptions the ambient polar space can be recovered in this complement.
We present the results of the study of the morphology and galaxy content of the Sloan Great Wall (SGW). We use the luminosity density field to determine superclusters in the SGW, and the fourth Minkowski functional V_3 and the morphological signature (the K_1-K_2 shapefinders curve) to show the different morphologies of the SGW, from a single filament to a multibranching, clumpy planar system. The richest supercluster in the SGW, SCl~126 and especially its core resemble a very rich filament, while another rich supercluster in the SGW, SCl~111, resembles a "multispider" - an assembly of high density regions connected by chains of galaxies. Using Minkowski functionals we study the substructure of individual galaxy populations determined by their color in these superclusters. We assess the statistical significance of the results with the halo model and smoothed bootstrap. We study the galaxy content and the properties of groups of galaxies in two richest superclusters of the SGW, paying special attention to bright red galaxies (BRGs) and to the first ranked galaxies in SGW groups. About 1/3 of BRGs are spirals. The scatter of colors of elliptical BRGs is smaller than that of spiral BRGs. About half of BRGs and of first ranked galaxies in groups have large peculiar velocities. Groups with elliptical BRGs as their first ranked galaxies populate superclusters more uniformly than the groups, which have a spiral BRG as its first ranked galaxy. The galaxy and group content of the core of the supercluster SCl~126 shows several differences in comparison with the outskirts of this supercluster and with the supercluster SCl~111. Our results suggest that the formation history and evolution of individual neighbour superclusters in the SGW has been different.
It has been recently suggested that the nonlinear optical processes in plasmonic nanoantennas allow for a substantial boost in the sensitivity of plasmonic sensing platforms. Here we present a sensing device based on an array of non-centrosymmetric plasmonic nanoantennas featuring enhanced second harmonic generation (SHG) integrated in a microfluidic chip. We evaluate its sensitivity both in the linear and nonlinear regime using a figure of merit (FOM = $(\Delta I/I)/\Delta n$) that accounts for the relative change in the measured intensity, \textit{I}, against the variation of the environmental refractive index \textit{n}. While the signal-to-noise ratio achieved in both regimes allows the detection of a minimum refractive index variation $\Delta n_{min} \approx 10^{-3}$, the platform operation in the nonlinear regime features a sensitivity (i.e. the FOM) that is at least 3 times higher than the linear one. Thanks to the surface sensitivity of plasmon-enhanced SHG, our results show that the development of such SHG sensing platforms with sensitivity performances exceeding those of their linear counterparts is within reach.
We used ionized gas and stellar kinematics for 667 spatially resolved galaxies publicly available from the Calar Alto Legacy Integral Field Area survey (CALIFA) 3rd Data Release with the aim of studying kinematic scaling relations as the Tully $\&$ Fisher (TF) relation using rotation velocity, $V_{rot}$, the Faber $\&$ Jackson (FJ) relation using velocity dispersion, $\sigma$, and also a combination of $V_{rot}$ and $\sigma$ through the $S_{K}$ parameter defined as $S_{K}^2 = KV_{rot}^2 + \sigma^2$ with constant $K$. Late-type and early-type galaxies reproduce the TF and FJ relations. Some early-type galaxies also follow the TF relation and some late-type galaxies the FJ relation, but always with larger scatter. On the contrary, when we use the $S_{K}$ parameter, all galaxies, regardless of the morphological type, lie on the same scaling relation, showing a tight correlation with the total stellar mass, $M_\star$. Indeed, we find that the scatter in this relation is smaller or equal to that of the TF and FJ relations. We explore different values of the $K$ parameter without significant differences (slope and scatter) in our final results with respect the case $K=0.5$ besides than a small change in the zero point. We calibrate the kinematic $S_{K}^2$ dynamical mass proxy in order to make it consistent with sophisticated published dynamical models within $0.15\ dex$. We show that the $S_{K}$ proxy is able to reproduce the relation between the dynamical mass and the stellar mass in the inner regions of galaxies. Our result may be useful in order to produce fast estimations of the central dynamical mass in galaxies and to study correlations in large galaxy surveys.
We study the open and closed axisymmetric marginally outer trapped surfaces contained in leaves of constant Painlev\'e-Gullstrand time for Schwarzschild spacetimes. We identify a family of closed MOTS in the black hole interior characterized by an arbitrary number of self-intersections. This suggests that the self-intersecting behaviour reported in [Phys.Rev.D 100, 084044 (2019)] may be a far more generic phenomenon than expected. We also consider open surfaces, finding that their behaviour is highly constrained but includes surfaces with multiple self-intersections inside the horizon. We argue that the behaviour of open MOTS identifies and constrains the possible local behaviour of MOTS during extreme mass ratio mergers.
We report X-ray observations of the High Mass X-ray Binary (HMXB) pulsar 4U 1907+09. Spectral and Timing analysis of the source has been performed using NuSTAR observation. Timing analysis of the photon events revealed the coherent X-ray pulsation of the source with a pulse period of $442.92\;\pm\;0.03$ s. It is observed that the source is spinning down at a rate of $0.1971(4) s yr^{-1}$. The pulse profile is characterized by a decaying amplitude of the secondary peak and relative growth in the amplitude of the primary peak with an increase in energy. The broad-band spectral coverage of NuSTAR has been used to observe multiple absorption features in the X-ray continuum of the source. We confirm the presence of two prominent cyclotron absorption features at $\sim 17$ keV and $\sim 38$ keV respectively. In addition, we have detected an absorption-line feature at $\sim 8$ keV, with an equivalent width of $\sim 1.3$ keV. The variation of the spectral parameters with pulse phase has been observed using phase-resolved spectroscopy and the relevant variabilities of the parameters have been discussed with the underlying physical implications. The continuum evolution and variations in spectral parameters have also been studied by time-resolved spectroscopy.
For a simple drawing $D$ of the complete graph $K_n$, two (plane) subdrawings are compatible if their union is plane. Let $\mathcal{T}_D$ be the set of all plane spanning trees on $D$ and $\mathcal{F}(\mathcal{T}_D)$ be the compatibility graph that has a vertex for each element in $\mathcal{T}_D$ and two vertices are adjacent if and only if the corresponding trees are compatible. We show, on the one hand, that $\mathcal{F}(\mathcal{T}_D)$ is connected if $D$ is a cylindrical, monotone, or strongly c-monotone drawing. On the other hand, we show that the subgraph of $\mathcal{F}(\mathcal{T}_D)$ induced by stars, double stars, and twin stars is also connected. In all cases the diameter of the corresponding compatibility graph is at most linear in $n$.
It is shown that EPR correlations are the angular analogue to the Hanbury-Brown--Twiss effect. As insight provided by this model, it is seen that, analysis of the EPR experiment requires conditional probabilities which do not admit the derivation of Bell inequalities.
Transition metal oxide memristors, or resistive random-access memory (RRAM) switches, are under intense development for storage-class memory because of their favorable operating power, endurance, speed, and density. Their commercial deployment critically depends on predictive compact models based on understanding nanoscale physico-chemical forces, which remains elusive and controversial owing to the difficulties in directly observing atomic motions during resistive switching, Here, using scanning transmission synchrotron x-ray spectromicroscopy to study in-situ switching of hafnium oxide memristors, we directly observed the formation of a localized oxygen-deficiency-derived conductive channel surrounded by a low-conductivity ring of excess oxygen. Subsequent thermal annealing homogenized the segregated oxygen, resetting the cells towards their as-grown resistance state. We show that the formation and dissolution of the conduction channel are successfully modeled by radial thermophoresis and Fick diffusion of oxygen atoms driven by Joule heating. This confirmation and quantification of two opposing nanoscale radial forces that affect bipolar memristor switching are important components for any future physics-based compact model for the electronic switching of these devices.
We perform one- and two-points magnitude cumulant analysis of one-dimensional longitudinal velocity profiles stemming from three different experimental set-ups and covering a broad range of Taylor scaled Reynolds numbers from 89 to 2500. While the first-order cumulant behavior is found to strongly depend on Reynolds number and experimental conditions, the second-order cumulant and the magnitude connected correlation functions are shown to display respectively universal scale and space-lag behavior. Despite the fact that the Extended Self-Similarity (ESS) hypothesis is not consistent with these findings, when extrapolating our results to the limit of infinite Reynolds number, one confirms the validity of the log-normal multifractal description of the intermittency phenomenon with a well defined intermittency parameter C2 = 0.025 +/- 0.003. But the convergence to zero of the magnitude connected correlation functions casts doubt on the asymptotic existence of an underlying multiplicative cascading spatial structure.
Combining high and low probability densities in intensity hybrids, we study some of their properties in double-slit setups. In particular, we connect to earlier results on beam attenuation techniques in neutron interferometry and study the effects of very small transmission factors, or very low counting rates, respectively, at one of the two slits. We use a "superclassical" modeling procedure which we have previously shown to produce predictions identical with those of standard quantum theory. Although in accordance with the latter, we show that there are previously unexpected new effects in intensity hybrids for transmission factors below $a\lesssim 10^{-4}$, which can eventually be observed with the aid of weak measurement techniques. We denote these as quantum sweeper effects, which are characterized by the bunching together of low counting rate particles within very narrow spatial domains. We give an explanation of this phenomenology by the circumstance that in reaching down to ever weaker channel intensities, the nonlinear nature of the probability density currents becomes ever more important, a fact which is generally not considered - although implicitly present - in standard quantum mechanics.
Beam asymmetries result in statistically-anisotropic cosmic microwave background (CMB) maps. Typically, they are studied for their effects on the CMB power spectrum, however they more closely mimic anisotropic effects such as gravitational lensing and primordial power asymmetry. We discuss tools for studying the effects of beam asymmetry on general quadratic estimators of anisotropy, analytically for full-sky observations as well as in the analysis of realistic data. We demonstrate this methodology in application to a recently-detected 9 sigma quadrupolar modulation effect in the WMAP data, showing that beams provide a complete and sufficient explanation for the anomaly.
We present high resolution 1.06 -- 1.28 micron spectra toward the interacting binary UY Aur obtained with GEMINI/NIFS and the AO system Altair. We have detected [FeII] $\lambda$~1.257 micron and [He I] $\lambda$~1.083 micron lines from both UY Aur A (the primary source) and UY Aur B (the secondary). In [Fe II] UY Aur A drives fast and widely opening outflows with an opening angle of ~ 90 degree along a position angle of ~40 degree, while UY Aur B is associated with a redshifted knot. The blueshifted and redshifted emissions show complicated structure between the primary and secondary.   The radial velocities of the [Fe II] emission features are similar for UY Aur A and B: ~ -100 km/s for the blueshifted emission and ~ +130 km/s for the red-shifted component. The [He I] line profile observed toward UY Aur A comprises a central emission feature with deep absorptions at both blueshifted and redshifted velocities. These absorption features may be explained by stellar wind models. The [He I] line profile of UY Aur B shows only an emission feature.
We show that time variations in the UV ionizing continuum of quasars, on scales of $\sim$1 year, affect the dynamic structure of the plasmas responsible for low ionization broad absorption lines. Variations of the ionizing continuum produce non-equilibrium photoionization conditions over a significant fraction of the absorbing clouds and supersonically moving ionization fronts. When the flux drops the contraction of the ionized region drives a supersonic cooling front towards the radiation source and a rarefaction wave in the opposite direction. The pressure imbalance is compensated by an increased speed of the cool gas relative to the front. When the flux recovers the cool gas is re-ionized and re-heated by a supersonic ionization front traveling away from the radiation source and a forward shock is created. The reheated clouds equilibrate to a temperature of $\sim 10^4$ K and are observed to have different radial velocities than the main cloud. Such fragmentation seems consistent with the multicomponent structure of troughs seen in some objects. The velocity differences measured among various components in the quasars QSO 2359--1241 and SDSS J0318--0600 can be reproduced by our model if strong magnetic fields ($\sim$10 mG) are present within the clouds.
In this paper we introduce a canonical quantum coarse-graining and use negentropy to connect ignorance as measured by quantum information entropy and ignorance related to quantum coarse-graining. For our procedure, macro-states are the set of purifications $\{|\bar{\Gamma}^{\rho}\rangle\}$ associated with density operator $\rho$ and micro-states are elements of $\{|\bar{\Gamma}^{\rho}\rangle\}$. Unlike other quantum coarse-graining procedures, ours always gives a well-defined unique coarse-graining of phase space. Our coarse-graining is also unique in that the volumes of phase space associated with macro-states are computed from differential manifolds whose metric components are constructed from the Lie group symmetries that generate $\{|\bar{\Gamma}^{\rho}\rangle\}$. We call these manifolds surfaces of ignorance, and their volumes quantify the lack of information in $\rho$ as measured by quantum information entropies. To show that these volumes behave like information entropies, we compare them to the von Neumann and linear entropies for states whose symmetries are given by $SO(3)$, $SU(2)$, and $SO(N)$. We also show that our procedure reproduces features of Boltzmann's original coarse-graining by showing that the majority of phase space consists of states near or at equilibrium. As a consequence of this coarse-graining, it is shown that an inherent flag variety structure underlies composite Hilbert spaces.
We show how an idealised measurement procedure can condense photons from two modes into one, and how, by feeding forward the results of the measurement, it is possible to generate efficiently superpositions of components for which only one mode is populated, commonly called ``N00N states''. For the basic procedure, sources of number states leak onto a beam splitter, and the output ports are monitored by photodetectors. We find that detecting a fixed fraction of the input at one output port suffices to direct the remainder to the same port with high probability, however large the initial state. When instead photons are detected at both ports, Schr\"{o}dinger cat states are produced. We describe a circuit for making the components of such a state orthogonal, and another for subsequent conversion to a N00N state. Our approach scales exponentially better than existing proposals. Important applications include quantum imaging and metrology.
We show by direct calculation starting from a microscopic model that the two-state system with time-dependent energy levels in the presence of fast quantum noise obeys the master equation. The solution of master equation is found analytically and analyzed in a broad range of parameters. The fast transverse noise affects the transition probability during much longer time (the accumulation time) than the longitudinal one. The action of the fast longitudinal noise is restricted by the shorter Landau-Zener time, the same as in the regular Landau-Zener process. The large ratio of time scales allows solving the Landau-Zener problem with longitudinal noise only, then solving the same problem with the transverse noise only and matching the two solutions. The correlation of the longitudinal and transverse noise renormalizes the Landau-Zener transition matrix element and can strongly enhance the survival probability, whereas the transverse noise always reduces it. Both longitudinal and transverse noise reduce the coherence. The decoherence time is inverse proportional to the noise intensity. If the noise is fast, its intensity at which the multi-quantum processes become essential corresponds to a deeply adiabatic regime. We briefly discuss possible applications of the general theory to the problem of the qubit decoherence and to the spin relaxation of molecular magnets.
We determine, for all genus $g\geq2$ the Riemann surfaces of genus $g$ with $4g$ automorphisms. For $g\neq$ $3,6,12,15$ or $30$, this surfaces form a real Riemann surface $\mathcal{F}_{g}$ in the moduli space $\mathcal{M}_{g}$: the Riemann sphere with three punctures. The set of real Riemann surfaces in $\mathcal{F}_{g}$ consists of three intervals its closure in the Deligne-Mumford compactification of $\mathcal{M}_{g}$ is a closed Jordan curve.
We study Schroder paths drawn in a (m,n) rectangle, for any positive integers m and n. We get explicit enumeration formulas, closely linked to those for the corresponding (m,n)-Dyck paths. Moreover we study a Schroder version of (m,n)-parking functions, and associated (q,t)-analogs.
The aim of this work is to construct certain homotopy t-structures on various categories of motivic homotopy theory, extending works of Voevodsky, Morel, D\'eglise and Ayoub. We prove these $t$-structures possess many good properties, some analogous to that of the perverse $t$-structure of Beilinson, Bernstein and Deligne. We compute the homology of certain motives, notably in the case of relative curves. We also show that their hearts provide convenient extensions of the theory of homotopy invariant sheaves with transfers, extending some of the main results of Voevodsky. These t-structures are closely related to Gersten weight structures as defined by Bondarko.