Miracle-dz/UniFAR-FTUs huggingface dataset:
The Origin of Parsec-Scale Gaseous and Stellar Disks in the Galactic Center and AGNs

The Galactic center stellar disk and the circumnuclear ring provide a unique opportunity to study in detail the dynamics and physical conditions of distant molecular disks in the nuclei of galaxies. One of the key questions is how these disks form so close to their host black holes and under what condition they form stars in a tidally stressed environment. We argue that disk formation around a massive black hole is due to partial accretion of extended molecular clouds that temporarily pass through the central region of the Galaxy. The cancellation of angular momentum of the gravitationally focused gas naturally creates a compact gaseous disk. The disk can potentially become gravitationally unstable and form stars. We apply these ideas to explain the origin of sub-parsec megamaser disks found in the nuclei of Seyfert 2 galaxies. We show that an empirical scaling relation between the mass of the black hole and the size of the disk can be understood in the context of the cloud capture scenario. We conclude that the stellar and gas disks found in our Galactic center act as a bridge to further our understanding of more distant mega-maser disks in the nuclei of Seyfert 2 galaxies.
Rogue waves statistics in the framework of one-dimensional Generalized Nonlinear Schrodinger Equation

We measure evolution of spectra, spatial correlation functions and probability density functions (PDFs) of waves appearance for a set of one-dimensional NLS-like equations of focusing type, namely for the classical integrable Nonlinear Schrodinger equation (1), nonintegrable NLS equation accounting for dumping (linear dissipation, two- and three-photon absorption) and pumping terms (2) and generalized NLS equation accounting for six-wave interactions, dumping and pumping terms (3). All additional terms beyond the classical NLS equation are small. As initial conditions we choose seeded by noise modulationally unstable solutions of the considered systems in the form of (a) condensate for systems (1)-(3) and (b) cnoidal wave for the classical NLS equation (1). We observe 'strange' results for the classical NLS equation (1) with condensate initial condition including peak at zeroth harmonic in averaged over ensemble spectra, non-decaying spacial correlation functions and a 'breathing' region on the PDFs for medium waves amplitudes where frequency of waves appearance oscillates with time, while the far-tails of the PDFs remain Rayleigh ones. Addition of small dumping and pumping terms in model (2) breaks integrability that results in absence of the peak at zeroth harmonic in spectra, spacial correlation functions decaying to zero level and strictly Rayleigh PDFs for waves amplitudes. For the classical NLS equation (1) with cnoidal wave initial condition PDFs turn out to be significantly different from Rayleigh ones with 'fat tails' in the region of large amplitudes where higher waves appear more frequently, while for generalized NLS equation with six-wave interactions, dumping and pumping terms (3) we demonstrate absence of non-Rayleigh addition to the PDFs for zeroth six-wave interactions coefficient and increase of non-Rayleigh addition with six-wave interactions term.
The ratio of luminous to faint red-sequence galaxies in X-ray and optically selected low-redshift clusters

ABSTRACT We study the ratio of luminous-to-faint red sequence galaxies in both optically andX-ray selected galaxy clusters in the poorly studied redshift range 0.05 6z <0.19. The X-ray selected sample consists of 112 clusters based on the ROSAT All-SkySurvey, while the optical sample consists of 266 clusters from the Sloan Digital SkySurvey. Our results are consistent with the presence of a trend in luminous-to-faintratio with redshift, conﬁrming that downsizing is continuous from high to low redshift.After correcting for the variations with redshift using a partial Spearman analysis, weﬁnd no signiﬁcant relationship between luminous-to-faint ratio and X-ray luminosityof the host cluster sample, in contrast to recent suggestions. Finally, we investigate thestacked colour-magnitude relations of these samples ﬁnding no signiﬁcant diﬀerencesbetween the slopes for optically and X-ray selected clusters. The colour-magnitudeslopes are consistent with the values obtained in similar studies, but not withpredictions of theoretical models.Keywords: cosmology: Large scale structure – galaxies: clusters: general – galaxies:evolution – galaxies: photometry.
A Design of NB-IOT Random Access Preamble Receiver for Large Frequency Offset

In the fifth generation (5G) and beyond, the satellite communication system is expected to support Narrowband Internet of Things (NB-IoT). However, the residual frequency offset in a channel may be large because of the large velocity of the satellites. In a legacy narrowband internet of things system, the users are assumed to have low velocity, and the random access preamble consists of single-subcarrier orthogonal frequency-division multiplexing symbols. With a large frequency offset, the power of the preamble leaks into adjacent subcarriers, which will cause severe performance degradation. In this paper, the influence of the leaked power is theoretically investigated, based on which a novel random access receiver is proposed to alleviate the performance degradation. The adjacent subcarriers are actually coherently combined to take advantages of the leaked power. The weights in combination are designed to suppress the interference of other users when the frequency offset is large. Numerical results show that the proposed receiver has good performance in preamble detection.
SEARCH FOR THE SUNYAEV–ZEL'DOVICH EFFECT IN A GIANT RADIO GALAXY B1358+305

We present results of an imaging observation of the central region of a giant radio galaxy B1358+305. The classical, standard scenario of Fanaroff–Riley II radio galaxies suggests that shock-produced hot electrons contained in a radio galaxy are a good reservoir of the jet-supplied energy from active nuclei. The aim of our observation is to search for the Sunyaev–Zel'dovich effect (SZE) induced by these hot electrons. The observation was performed at 21 GHz with the Nobeyama 45 m telescope. Deep imaging observation of a wide region of size 6. ′7 × 6. ′7 with the beam size θHPBW = 81. ″2 enables the most detailed examination of the possible thermal energy of electrons contained in a radio galaxy. The resultant intensity fluctuation is 0.56 mJy beam−1 (in terms of the Compton y-parameter, y = 1.04 × 10−4) at a 95% confidence level. The intensity fluctuation obtained with imaging analysis sets the most stringent upper limit on the fluctuations in the central region of a giant radio galaxy obtained so far, and our results will be a toehold for future plans of SZE observation in a radio galaxy.
Annealed imitation: fast dynamics for maximum clique

We propose a new class of heuristics for the maximum clique problem (MCP) whose basic ingredients are: (1) a parameterized continuous formulation of MCP, (2) an instability analysis of equilibria of imitation dynamics from evolutionary game theory, and (3) a principled way of varying a regularization parameter during the evolution process so as to avoid inefficient solutions. The resulting annealed imitation" class is shown to contain algorithms that are dramatically faster than and as accurate as state-of-the-art neural network heuristics for maximum clique.
Selective dynamical decoupling for quantum state transfer

State transfer across discrete quantum networks is one of the elementary tasks of quantum information processing. Its aim is the faithful placement of information into a specific position in the network. However, all physical systems suffer from imperfections, which can severely limit the transfer fidelity. We present selective dynamical decoupling schemes which are capable of stabilizing imperfect quantum state transfer protocols on the model of a bent linear qubit chain. The efficiency of the schemes is tested and verified in numerical simulations on a number of realistic cases. The simulations demonstrate that these selective dynamical decoupling schemes are capable of suppressing unwanted errors in quantum state transfer protocols efficiently.
Properties of Ambiguity Functions

Mulcahy-Stanislawczyk, John M.S.E.C. E. , Purdue University, May 2014. Properties of Ambiguity Functions. Major Professor: Mark R. Bell. The use of ambiguity functions in radar signal design and analysis is very common. Understanding the various properties and meanings of ambiguity functions allow a signal designer to understand the time delay and doppler shift properties of a given signal. Through the years, several di↵erent versions of the ambiguity function have been used. Each of these functions essentially have the same physical meaning; however, the use of di↵erent functions makes it di cult to be sure that certain properties hold for di↵erent formulations. This work proves several parallel properties of two versions of the asymmetric ambiguity function, the symmetric ambiguity function, and Woodwords original ambiguity function. It also provides some visualizations comparing the ambiguity functions for some common signals.
Fanaroff–Riley dichotomy of radio galaxies and the Malmquist bias

We examine the possibility that a claimed dependence of the FR 1/2 break value in radio luminosity on the absolute magnitude of the optical host galaxy could be due to the Malmquist bias, where a redshift-luminosity correlation appears in a flux-limited sample because of an observational selection effect. In such a sample, the redshift dependence of a phenomenon could appear as a luminosity-dependent effect and may not be really representing an intrinsic property of the radio sample. We test this on the radio complete MRC (Molonglo Reference Catalog) sample, where Spearman rank correlation and Kendall rank correlation tests show that the correlations are indeed stronger between the redshift and the optical luminosity than that between the radio luminosity and the optical luminosity, suggesting that the latter correlation perhaps arises because of the Malmquist Bias. We further show that similar effects of the Malmquist bias could also be present elsewhere in other correlations claimed in the literature between the radio luminosity and other observed properties of FR1 and FR2 sources.
Counting Individual Trapped Electrons on Liquid Helium

We show that small numbers of electrons, including a single isolated electron, can be held in an electrostatic trap above the surface of superfluid helium. A potential well is created using microfabricated electrodes in a 5 μm diameter pool of helium. Electrons are injected into the trap from an electron reservoir on a helium microchannel. They are individually detected using a superconducting single-electron transistor as an electrometer. A Coulomb staircase is observed as electrons leave the trap one–by–one until the trap is empty. A design for a scalable quantum information processor using an array of electron traps is presented.
Distances of the TeV supernova remnant complex CTB 37 towards the Galactic bar

Three supernova remnants (SNRs) form the CTB 37 complex: CTB 37A (G348.5+0.1, associated with the TeV γ-ray source HESS J1714−385), CTB 37B (G348.7+0.3, associated with HESS J1713−381 and the magnetar CXOU J171405.7.381031) and G348.5−0.0. We use 21-cm H i absorption measurements to constrain kinematic distances to these SNRs, which have not previously been determined well. We revise the kinematic distance for CTB 37A to be in the range 6.3–9.5 kpc (previously ∼11.3 kpc) because it is beyond the near 3-kpc arm and in front of the far side of the CO cloud at −145 km s−1 towards l= 348.5. G348.5−0.0 has an H i column density (∼6.1×1021 cm−2) lower than CTB 37A (∼7.1 × 1021 cm−2). Also, G348.5−0.0 does not have the major absorption feature at −107 km s−1 that CTB 37A shows. This is caused by the near 3-kpc arm, so G348.5−0.0 is at a distance of ≤6.3 kpc. CTB 37B is at a distance of ∼13.2 kpc (previously 5–9 kpc) based on: (1) it has an absorption feature at −10 ± 5 km s−1 from the far 3-kpc arm, so CTB 37B is behind it; (2) there is absorption at −30 km s−1 but not at −26 km s−1, which yields the distance value; and (3) the H i column density towards CTB 37B (∼8.3 × 1021 cm−2) is larger than that towards CTB 37A. In summary, CTB 37A, CTB 37B and G348.5+0.0 are all at different distances and are only by chance nearby each other on the sky. In addition, we conclude that CTB 37A and 37B are not associated with the historical supernova AD 393.
Prospects on Nambu Bracket

We review recent progress in formulating the worldvolume theory of the M2-branes using the Nambu bracket. Although it is generally agreed that this formulation should be replaced by another using the superconformal Chern-Simons theory, we try to pursue a possible complementary role played by the Nambu bracket. Since the partition function of the superconformal Chern-Simons theory implies a hidden super gauge group, we study the supersymmetric generalization of the Nambu bracket. We construct explicitly the super unitary Nambu algebra.
Age of the Universe, Average Deceleration Parameter and Possible Implications for the End of Cosmology

A new expression to the total age of the Universe is derived in terms of the average deceleration parameter. This kinematic result holds regardless of the curvature of the universe as well as of the underlying gravity theory. It remains valid even in the context of brane-world motivated cosmologies. Since the present age parameter of the Universe is accurately adjusted to $H_0t_0 = 1$, it is shown that the time averaged value of the deceleration parameter is zero. This also means that the cosmic age today is exactly the one predicted by a relativistic flat cosmological model filled by K-matter, a fluid satisfying the equation of state $p = -{{1/3}}\rho$. By assuming the validity of this relation (in an average long time meaning), it is argued that the decelerating stages of the expansion must exactly be compensated by the accelerated phases, as if the observed Universe coasts forever. If this is true, the present accelerating stage must be followed by a subsequent decelerating phase as predicted by some recent scalar field and brane-world motivated cosmologies.
THE FIRST FERMI LAT SUPERNOVA REMNANT CATALOG

To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope (LAT). Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude allows us to determine an upper limit of 22% on the number of GeV candidates falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, we demonstrate the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. We model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.
Comparison of perturbations in fluid and scalar field models of dark energy

We compare perturbations in a fluid model of dark energy with those in a scalar field. As compared to the {lambda}CDM model, large scale matter power spectrum is suppressed in fluid model as well as in a generic quintessence dark energy model. To check the efficacy of fluid description of dark energy in emulating a scalar field, we consider a potential which gives the same background evolution as a fluid with a constant equation of state. We show that for sub-Hubble scales, a fluid model effectively emulates a scalar field model. At larger scales, where dark energy perturbations may play a significant role, the fluid analogy breaks down and the evolution of matter density contrast depends on individual scalar field models.
An Efficient Method for Solving the Brusselator System

In this paper, a new efficient recurrence relation is constructed to solve a nonlinear Brusselator equation. The system, known as the reaction-diffusion Brusselator, arises in the modeling of certain diffusion processes. The Laplace transform method and the new homotopy perturbation method (NHPM) are used to solve these equations. Since mathematical modeling of numerous scientific and engineering experiment lead to the Brusselator equation, it is worthwhile to try new methods to solve this system. Comparison of the results with those of the homotopy perturbation method, the Adomian decomposition method and the dual-reciprocity boundary element method leads to significant consequences. The method is tested using various examples and the results show that the new method is more effective and convenient to use, and has an evident high accuracy rate.
The K-Book: An Introduction to Algebraic K-Theory

Projective modules and vector bundles The Grothendieck group $K_0$ $K_1$ and $K_2$ of a ring Definitions of higher $K$-theory The fundamental theorems of higher $K$-theory The higher $K$-theory of fields Nomenclature Bibliography Index
Devil's staircase, spontaneous-DC bias, and chaos via quasiperiodic plasma oscillations in semiconductor superlattices

We study a plasma instability in semiconductor superlattices irradiated by a monochromatic, pure AC electric field. The instability leads to sustained oscillations at a frequency \omega 2 that is either incommensurate to the drive, or frequency-locked to it, \omega 2 = (p/q) \omega. A spontaneously generated DC bias is found when either p or q in the locking ratio are even integers. Frequency locked regions form Arnol'd tongues in parameter space and the ratio \omega 2 / \omega\ exhibits a Devil's staircase. A transition to chaotic motion is observed as resonances overlap.
Synchronisation of chaotic systems via reduced observers

This paper treats synchronization problem of chaotic systems from a novel point of view, by using a change of coordinates to transform chaotic systems into a common canonical form, for which the synchronization problem can be easily studied via reduced observer. Sufficient and neces- sary conditions are given and the proposed method is illustrated by the synchronization of R ossler chaotic system.
Measuring the beaming angle of GRB 030329 by fitting the rebrightenings in its multiband afterglow

Multiple rebrightenings have been observed in the multiband afterglow of GRB 030329. Especially, a marked and quick rebrightening occurred at about t ~ 1.2 * 10^5 s. Energy injection from late and slow shells seems to be the best interpretation for these rebrightenings. Usually it is assumed that the energy is injected into the whole external shock. However, in the case of GRB 030329, the rebrightenings are so quick that the usual consideration fails to give a satisfactory fit to the observed light curves. Actually, since these late/slow shells coast freely in the wake of the external shock, they should be cold and may not expand laterally. The energy injection then should only occur at the central region of the external shock. Considering this effect, we numerically re-fit the quick rebrightenings observed in GRB 030329. By doing this, we were able to derive the beaming angle of the energy injection process. Our result, with a relative residual of only 5% - 10% during the major rebrightening, is better than any previous modeling. The derived energy injection angle is about 0.035. We assume that these late shells are ejected by the central engine via the same mechanism as those early shells that produce the prompt gamma-ray burst. The main difference is that their velocities are much slower, so that they catch up with the external shock very lately and manifest as the observed quick rebrightenings. If this were true, then the derived energy injection angle can give a good measure of the beaming angle of the prompt gamma-ray emission. Our study may hopefully provide a novel method to measure the beaming angle of gamma-ray bursts.
On the Calibration of an Optical, High-Speed, Multiphase Microfluidic Sensor With Droplet Counting Applications in Lab-on-PCB Devices

The integration of microfluidics and droplet-based systems has led to platforms capable of characterizing multiple phases inside microchannels which can be an asset for many industries. Furthermore, recent developments on Lab-on-a-PCB devices focus to meet design specifications such as the ASSURED criteria (Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment-free, and Deliverable to end-users). However, most of these systems still present external equipment dependencies, complex setup and manufacturing processes, low reproducibility, along reduced information regarding calibration processes for ASSURED-based sensors. In this work, we developed a rapid and fully integrated calibration process for optical droplet-based Lab-on-PCB devices by means of an interfacial distance constant called <inline-formula> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula>, to obtain reliable and wide spectrum droplet detection and characterization results. To test the proposed calibration process, a low-cost optical droplet sensor was built using commonly available electronics components, consisting only of a fluid channel between a Light-Emitting Diode (LED) and a Light Dependent Resistor (LDR), which voltage variation is measured and processed with an Arduino Uno. After the proposed <inline-formula> <tex-math notation="LaTeX">$\lambda $ </tex-math></inline-formula> calibration of the platform, we were able to characterize different multiphase flow properties such as velocity, flow rate, droplet lengths, and volume for velocities up to 1000 droplets per second with the Mean Relative Errors (MRE) ranging from 2.4% up to 17%. The lowest MRE value was obtained using a two-phase flow system for flow from <inline-formula> <tex-math notation="LaTeX">$20 \mu \text{L}$ </tex-math></inline-formula>/min up to <inline-formula> <tex-math notation="LaTeX">$425 \mu \text{L}$ </tex-math></inline-formula>/min. In contrast, the highest MRE value we report was found for a three-phase flow system for droplets at <inline-formula> <tex-math notation="LaTeX">$250 \mu \text{L}$ </tex-math></inline-formula>/min.