cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Non-classical correlations between a C-band telecom photon and a stored spin-wave
Creators: name: Farrera, Pau
name: Maring, Nicolas
name: Albrecht, Boris
name: Heinze, Georg
name: de Riedmatten, Hugues
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Future ground-based quantum information networks will likely use single photons transmitted through optical fibers to entangle individual network nodes. To extend communication distances and overcome limitations due to photon absorption in fibers the concept of quantum repeaters has been proposed. For that purpose, it is required to achieve quantum correlations between the material nodes and photons at telecom wavelengths which can be sent over long distances in optical fibers. Here we demonstrate non-classical correlation between a frequency converted telecom C-band photon and a spin-wave stored in an atomic ensemble quantum memory. The photons emitted from the ensemble and heralding the spin-waves are converted from 780 nm to 1552 nm by means of an all-solid-state integrated waveguide non-linear device. We show ultra-low noise operation of the device enabling a high signal to noise ratio of the converted single photon, leading to a high spin-wave heralding efficiency. The presented work is an enabling step towards the practical entanglement of remote quantum memories and the entanglement of quantum systems operating at different wavelengths.
description: 9 pages, 5 figures
Correlation Effects on Charge Order and Zero-Gap State in the Organic Conductor α-(BEDT-TTF)2I3
Creators: name: Tanaka, Yasuhiro
name: Ogata, Masao
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The effects of electron correlation in the quasi-two-dimensional organic conductor α-(BEDT-TTF)2I3 are investigated theoretically by using an extended Hubbard model with on-site and nearest-neighbor Coulomb interactions. A variational Monte Carlo method is applied to study its ground-state properties. We show that there appears a nonmagnetic horizontal-stripe charge order in which nearest-neighbor correlation functions indicate a tendency toward a spin-singlet formation on the bonds with large transfer integrals along the charge-rich stripe. Under uniaxial pressure, a first-order transition from the nonmagnetic charge order to a zero-gap state occurs. Our results on a spin correlation length in the charge-ordered state suggest that a spin gap is almost unaffected by the uniaxial pressure in spite of the suppression of the charge disproportionation. The relevance of these contrasting behaviors in spin and charge degrees of freedom to recent experimental observations is discussed.
description: 15 pages, 9 figures, accepted for publication in J. Phys. Soc. Jpn
fairDMS: Rapid Model Training by Data and Model Reuse
Creators: name: Ali, Ahsan
name: Sharma, Hemant
name: Kettimuthu, Rajkumar
name: Kenesei, Peter
name: Trujillo, Dennis
name: Miceli, Antonino
name: Foster, Ian
name: Coffee, Ryan
name: Thayer, Jana
name: Liu, Zhengchun
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Extracting actionable information rapidly from data produced by instruments such as the Linac Coherent Light Source (LCLS-II) and Advanced Photon Source Upgrade (APS-U) is becoming ever more challenging due to high (up to TB/s) data rates. Conventional physics-based information retrieval methods are hard-pressed to detect interesting events fast enough to enable timely focusing on a rare event or correction of an error. Machine learning~(ML) methods that learn cheap surrogate classifiers present a promising alternative, but can fail catastrophically when changes in instrument or sample result in degradation in ML performance. To overcome such difficulties, we present a new data storage and ML model training architecture designed to organize large volumes of data and models so that when model degradation is detected, prior models and/or data can be queried rapidly and a more suitable model retrieved and fine-tuned for new conditions. We show that our approach can achieve up to 100x data labelling speedup compared to the current state-of-the-art, 200x improvement in training speed, and 92x speedup in-terms of end-to-end model updating time.
From Mirrors to Windows: Lyman-Alpha Radiative Transfer in a Very Clumpy Medium
Creators: name: Gronke, Max
name: Dijkstra, Mark
name: McCourt, Michael
name: Oh, S. Peng
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Lyman-Alpha (Ly$α$) is the strongest emission line in the Universe and is frequently used to detect and study the most distant galaxies. Because Lya is a resonant line, photons typically scatter prior to escaping; this scattering process complicates the interpretation of Ly$α$ spectra, but also encodes a wealth of information about the structure and kinematics of neutral gas in the galaxy. Modeling the Ly$α$ line therefore allows us to study tiny-scale features of the gas, even in the most distant galaxies. Curiously, observed Ly$α$ spectra can be modeled successfully with very simple, homogeneous geometries (such as an expanding, spherical shell), whereas more realistic, multiphase geometries often fail to reproduce the observed spectra. This seems paradoxical since the gas in galaxies is known to be multiphase. In this Letter, we show that spectra emerging from extremely clumpy geometries with many clouds along the line of sight converge to the predictions from simplified, homogeneous models. We suggest that this resolves the apparent discrepancy, and may provide a way to study the gas structure in galaxies on scales far smaller than can be probed in either cosmological simulations or direct (i.e., spatially-resolved) observations.
description: 6 pages, 4 figures; submitted to ApJL
Design of Robust Adaptive Beamforming Algorithms Based on Low-Rank and Cross-Correlation Techniques
Creators: name: Ruan, H.
name: de Lamare, R. C.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: This work presents cost-effective low-rank techniques for designing robust adaptive beamforming (RAB) algorithms. The proposed algorithms are based on the exploitation of the cross-correlation between the array observation data and the output of the beamformer. Firstly, we construct a general linear equation considered in large dimensions whose solution yields the steering vector mismatch. Then, we employ the idea of the full orthogonalization method (FOM), an orthogonal Krylov subspace based method, to iteratively estimate the steering vector mismatch in a reduced-dimensional subspace, resulting in the proposed orthogonal Krylov subspace projection mismatch estimation (OKSPME) method. We also devise adaptive algorithms based on stochastic gradient (SG) and conjugate gradient (CG) techniques to update the beamforming weights with low complexity and avoid any costly matrix inversion. The main advantages of the proposed low-rank and mismatch estimation techniques are their cost-effectiveness when dealing with high dimension subspaces or large sensor arrays. Simulations results show excellent performance in terms of the output signal-to-interference-plus-noise ratio (SINR) of the beamformer among all the compared RAB methods.
description: 11 figures, 12 pages
Estimating and Penalizing Induced Preference Shifts in Recommender Systems
Creators: name: Carroll, Micah
name: Dragan, Anca
name: Russell, Stuart
name: Hadfield-Menell, Dylan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: The content that a recommender system (RS) shows to users influences them. Therefore, when choosing a recommender to deploy, one is implicitly also choosing to induce specific internal states in users. Even more, systems trained via long-horizon optimization will have direct incentives to manipulate users: in this work, we focus on the incentive to shift user preferences so they are easier to satisfy. We argue that - before deployment - system designers should: estimate the shifts a recommender would induce; evaluate whether such shifts would be undesirable; and perhaps even actively optimize to avoid problematic shifts. These steps involve two challenging ingredients: estimation requires anticipating how hypothetical algorithms would influence user preferences if deployed - we do this by using historical user interaction data to train a predictive user model which implicitly contains their preference dynamics; evaluation and optimization additionally require metrics to assess whether such influences are manipulative or otherwise unwanted - we use the notion of "safe shifts", that define a trust region within which behavior is safe: for instance, the natural way in which users would shift without interference from the system could be deemed "safe". In simulated experiments, we show that our learned preference dynamics model is effective in estimating user preferences and how they would respond to new recommenders. Additionally, we show that recommenders that optimize for staying in the trust region can avoid manipulative behaviors while still generating engagement.
description: Accepted to ICML 2022 (Spotlight)
Microwave assisted, Cu-catalyzed synthesis of sulfonamides using sodium sulfinates and amines
Creators: name: Nikam, Anil
name: Jadhav, Jagannath
name: Sankpal, Sagar
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biophysics
subject: Biochemistry
subject: Space Science
subject: Physical Sciences not elsewhere classified
subject: Medicine
subject: Pharmacology
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Marine Biology
subject: Plant Biology
subject: FOS: Biological sciences

description: An efficient procedure has been developed under microwave irradiation for the monosulfonylation of amines in acetonitrile:water. In this reaction, equimolar quantities of amines and sodium sulfinates were reacted in presence of CuBr2 and omitted the use of oxidants, ligands, additives, and bases. The developed methodology converts a wide array of sterically and electronically diverse sulfinate and amines into the corresponding sulfonamides in excellent yields within a short reaction time. The use of microwave and aqueous media makes this protocol potentially useful in the development of a green strategy for the synthesis of sulfonamides.
Transverse forces on vortices in superfluids in a periodic potential
Creators: name: Sonin, E. B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: The paper analyzes the transverse forces (the Magnus and the Lorentz forces) on vortices in superfluids put into periodic potentials at $T=0$. The case of weak potential and the tight-binding limit described by the Bose-Hubbard model were addressed. The analysis was based on the balance of true momentum and quasimomentum. A special attention was paid to the superfluid close to the superfluid-insulator transition. In this area of the phase diagram the theory predicts the particle-hole symmetry line where the Magnus force changes sign with respect to that expected from the sign of velocity circulation. Our analysis has shown that the magnitude of the Magnus force is a continuous function at crossing the particle-hole symmetry line. This challenges the theory connecting the magnitude of the Magnus force with topological Chern numbers and predicting a jump at crossing this line. Disagreement is explained by the role of intrinsic pinning and guided vortex motion ignored in the topological approach. It is one more evidence that in general topological arguments are not sufficient for derivation of equations of vortex motion.
description: 14 pages, 4 figures
Control of fuel target implosion non-uniformity in heavy ion inertial fusion
Creators: name: Iinuma, T.
name: Karino, T.
name: Kondo, S.
name: Kubo, T.
name: Kato, H.
name: Suzuki, T.
name: Kawata, S.
name: Ogoyski, A. I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: In inertial fusion, one of scientific issues is to reduce an implosion non-uniformity of a spherical fuel target. The implosion non-uniformity is caused by several factors, including the driver beam illumination non-uniformity, the Rayleigh-Taylor instability (RTI) growth, etc. In this paper we propose a new control method to reduce the implosion non-uniformity; the oscillating implosion acceleration dg(t) is created by pulsating and dephasing heavy ion beams (HIBs) in heavy ion inertial fusion (HIF). The dg(t) would reduce the RTI growth effectively. The original concept of the non- uniformity control in inertial fusion was proposed in (Kawata, et al., 1993). In this paper it was found that the pulsating and dephasing HIBs illumination provide successfully the controlled dg(t) and that dg(t) induced by the pulsating HIBs reduces well the implosion non-uniformity. Consequently the pulsating HIBs improve a pellet gain remarkably in HIF.
description: 10 pages, 10 figures, 2 tables, submitted to a journal
In silico molecular docking study and nano TiO2-SiO2 catalyzed microwave facilitated synthesis of new bis(α-aminophosphonates) as potential anti-diabetic agents
Creators: name: Kumar, Mahankali Pavan Phani
name: Vejendla, Anuradha
name: Malar, C. Gladis Raja
name: Chennamsetty, Subramanyam
name: Talari, Subrahmanyam
name: Vedula, Nagalakshmi
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Physiology
subject: Pharmacology
subject: Chemical Sciences not elsewhere classified
subject: Information Systems not elsewhere classified
subject: Developmental Biology
subject: Plant Biology
subject: Virology

description: In the present work, we have developed a greener approach to synthesize a series of novel bis(α-aminophosphonates) (bis(α-Aps)) via a microwave-mediated nano TiO2-SiO2 catalyzed Kabachnik-Fields (K-F) reaction under solvent-free conditions. An in silico molecular docking analysis was performed on all the designed molecules prior to their synthesis to get insight into their capacity to block the enzymes, α-amylase (PDB ID:3IJ8) and α-glucosidase (PDB ID:1OBB). The molecules with significant binding affinity were synthesized and spectroscopically analyzed to confirm their structure. They were screened further in vitro for their inhibitory activity on the target enzymes. When compared with the reference drug, the compounds diethyl[(2H‐1,3‐benzodioxol‐5‐yl)[(6‐{[(2H‐1,3‐benzodioxol‐5‐yl)(diethoxyphosphoryl)-methyl]amino}‐10,10‐dioxo‐9H‐10λ6‐thioxanthen‐3‐yl)amino]-methyl]phosphonate (4h), diethyl [(anthracen-9-yl)[(6-{[(anthracen-9-yl)(diethoxyphosphoryl)methyl]amino}-10,10-dioxo-9H-10λ6-thioxanthen-3-yl)amino]-methyl]phosphonate (4i) have shown greater inhibition, and diethyl{[(6‐{[(diethoxyphosphoryl)(phenyl)methyl]amino}‐10,10‐dioxo‐9H‐10λ6‐thioxanthen‐3‐yl)amino](phenyl)methyl}phosphonate (4a), diethyl {[(6-{[(diethoxyphosphoryl)(4-hydroxy-3-nitrophenyl)methyl]amino}-10,10-dioxo-9H-10λ6-thioxanthen-3-yl)amino](4-hydroxy-3-nitrophenyl)methyl}phosphonate (4e) have shown equal inhibition against the α-amylase enzyme. Compounds diethyl{[(6‐{[(diethoxyphosphoryl)(phenyl)methyl]amino}‐10,10‐dioxo‐9H‐10λ6‐thioxanthen‐3‐yl)-amino](phenyl)methyl}phosphonate (4a), diethyl[(2H‐1,3‐benzodioxol‐5‐yl)[(6‐{[(2H‐1,3‐benzodioxol‐5‐yl)(diethoxyphosphoryl)methyl]amino}‐10,10‐dioxo‐9H‐10λ6‐thioxanthen‐3‐yl)amino]methyl]phosphonate (4h), and diethyl [(anthracen-9-yl)[(6-{[(anthracen-9-yl)(diethoxyphosphoryl)methyl]amino}-10,10-dioxo-9H-10λ6-thioxanthen-3-yl)amino]-methyl]phosphonate (4i) have shown superior inhibition and diethyl{[(6‐{[(diethoxyphosphoryl)(naphthalen‐1‐yl)methyl]amino}‐10,10‐dioxo‐9H‐10λ6‐thioxanthen‐3‐yl)amino](naphthalen‐1‐yl)methyl}phosphonate (4 g) has shown equal inhibition against the α-glucosidase enzyme. All the remaining compounds displayed modest to good inhibition when compared with the reference drug, Acarbose.
Novel thiourea derivatives against Mycobacterium tuberculosis: synthesis, characterization and molecular docking studies
Creators: name: Kutlu, Emine
name: Emen, Fatih Mehmet
name: Yıldırım, Kübra
name: Ataş, Cemilenur
name: Demirdogen, Ruken Esra
name: Yesilkaynak, Tuncay
name: Kinaytürk, Neslihan Kaya
name: Şimşek, Ece
name: Çoban, Ahmet Yılmaz
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Genetics
subject: Molecular Biology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Hematology
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: N-((2-chloropyridin-3-yl)carbamothioyl)thiophene-2-carboxamide (HL1), N-((6-methylpyridin-2-yl)carbamothioyl)thiophene-2-carboxamide (HL2), N-(allylcarbamothioyl)thiophene-2-carboxamide (HL3), 2-chloro-N-(methyl(1-phenylethyl)carbamothioyl)benzamide (HL4) and 2-chloro-N-(bis((R)-1-phenylethyl)carbamothioyl)benzamide (HL5) were synthesized and characterized via FT-IR, 1H-NMR, 13C-NMR and HR-MS techniques and HL3 was characterized via a single crystal X-ray diffraction experiment. The antituberculosis activity of the synthesized thiourea derivatives was tested against the H37RV (ATCC27294), ATCC35822 (INH resistant), ATCC35838 (RIF resistant), ATCC35820 (STM resistant) and ATCC35837 (EMB resistant) standard bacteria strains. The thiourea derivatives were tested on two MDR and one primary drug-sensitive isolates with the microplate nitrate reductase test method. The results indicated that HL2 and HL3 had tuberculosis activity on some of the isolates. It was observed that HL4 was the most effective among all the thiourea derivatives. The interaction mechanism of the synthesized compounds on 2X23, a tuberculosis protein, was investigated via molecular docking method. The interaction was observed to occur over S and Cl atoms in all the compounds. The compounds containing the methyl group were observed to interact via this group.
Electronic and structural properties of RbCeX$_2$ (X$_2$: O$_2$, S$_2$, SeS, Se$_2$, TeSe, Te$_2$)
Creators: name: Ortiz, Brenden R.
name: Bordelon, Mitchell M.
name: Bhattacharyya, Pritam
name: Pokharel, Ganesh
name: Sarte, Paul M.
name: Posthuma, Lorenzo
name: Petersen, Thorben
name: Eldeeb, Mohamed S.
name: Granroth, Garrett E.
name: Cruz, Clarina R. Dela
name: Calder, Stuart
name: Abernathy, Douglas L.
name: Hozoi, Liviu
name: Wilson, Stephen D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Triangular lattice delafossite compounds built from magnetic lanthanide ions are a topic of recent interest due to their frustrated magnetism and realization of quantum disordered magnetic ground states. Here we report the evolution of the structure and electronic ground states of RbCe$X_2$ compounds, built from a triangular lattice of Ce$^{3+}$ ions, upon varying their anion character ($X_2$= O$_2$, S$_2$, SeS, Se$_2$, TeSe, Te$_2$). This includes the discovery of a new member of this series, RbCeO$_2$, that potentially realizes a quantum disordered ground state analogous to NaYbO$_2$. Magnetization and susceptibility measurements reveal that all compounds manifest mean-field antiferromagnetic interactions and, with the exception of the oxide, possess signatures of magnetic correlations onset below 1 K. The crystalline electric field level scheme is explored via neutron scattering and \textit{ab initio} calculations in order to model the intramultiplet splitting of the $J=5/2$ multiplet. In addition to the two excited doublets expected within the $J=5/2$ manifold, we observe one extra, local mode present across the sample series. This added mode shifts downward in energy with increasing anion mass and decreasing crystal field strength, suggesting a long-lived anomalous mode endemic to anion motion about the Ce$^{3+}$ sites.
description: 12 pages, 7 figures
Ultrasound-assisted construction of novel diethyl {(4-oxo-1,4-dihydroquinolin-3-yl) (aryl/heteroarylamino)methyl}phosphonates using CdI2 nanoparticles as an efficient catalyst: Synthesis, characterization, and antifungal properties
Creators: name: Hussien, Mohamed
name: Ali, Tarik E.
name: Sayed, Ibrahim El-Tantawy El
name: Abdelaleem, Abdelaleem Hassan
name: Torkey, H. M.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Space Science
subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Pharmacology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Mental Health
subject: Plant Biology

description: The synthesis of some novel diethyl {(4-oxo-1,4-dihydroquinolin-3-yl)(aryl/heteroaryl-amino)methyl}phosphonates, was achieved. The methodology is based on one-pot three-component reaction of 4-oxo-1,4-dihydroquinoline-3-carboxaldehyde (1), amine, and diethyl phosphite in the presence of CdI2 nanoparticles as an efficient catalyst under conventional heating at 80 °C or ultrasound irradiation at 50 °C. The mild reaction conditions, operational simplicity, and excellent yields are the essential advantages of this protocol. Most of the products recorded inhibitory effects toward plant pathogenic fungi nearly to the standard control. The hybridization between diethyl α-aminophosphonate and quinolin-4-one moieties clubbed with sulfonamide, antipyrine, or 1,2,4-triazine in one molecular frame displayed good antifungal activities.
Novel 4H-pyrimido[2,1-b]benzothiazoles derivatives: Camphorsulphonic acid catalyzed enantioselective synthesis, optimization, and biological study
Creators: name: Bhoi, Manoj N.
name: Borad, Mayuri A.
name: Solanki, Ankita P.
name: Patel, Hitesh D.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: Biochemistry
Space Science
Medicine
Pharmacology
Biotechnology
Chemical Sciences not elsewhere classified
Developmental Biology

description: An efficient, highly convergent route for the synthesis of novel fourteen single isomer derivatives of ethyl-2-methyl-4-(pyridin-2-yl)-4H-benzo[4,5]thiazolo[3,2-a]pyrimidine-3-carboxylate have been developed by one-pot, three-component reaction between pyridine 2-aldehyde, β-ketoester and various derivatives of 2-amino benzothiazole in the presence of D-(+)-10-camphorsulphonic acid (D-(+)-10-CSA) as an effective chiral acid catalyst. Under the optimized conditions with 20 mol% catalyst loading, a wide range of optically active 4H-pyrimido[2,1-b]benzothiazole derivatives were obtained in good yields (up to 82%) with good to excellent enantioselectivities (84-99�). Their structures were elucidated by various spectroscopic methods such as 1H-NMR, 13C-NMR, Chiral HPLC, mass and elemental analysis. The attractive feature of this approach is one-pot synthesis, good yield, environment benign, mild reaction condition, simple, efficient, excellent stereoselectivity, water soluble catalyst and easy workup. All the final scaffolds have been screened for antibacterial activity. Among them, 4a’, 4c’, 4d’, 4e’, 4f’, 4g’, 4j’,4m’ and 4n’ were proven to possess enhanced antibacterial properties as compared to the standard drug.
Lattice study of a magnetic contribution to heavy quark momentum diffusion
Creators: name: Banerjee, D.
name: Datta, S.
name: Laine, M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Heavy quarks placed within a hot QCD medium undergo Brownian motion, characterized by specific transport coefficients. Their determination can be simplified by expanding them in $T/M$, where $T$ is the temperature and $M$ is a heavy quark mass. The leading term in the expansion originates from the colour-electric part of a Lorentz force, whereas the next-to-leading order involves the colour-magnetic part. We measure a colour-magnetic 2-point correlator in quenched QCD at $T \sim 1.2 ... 2.0 T_{\rm c}^{ }$. Employing multilevel techniques and non-perturbative renormalization, a good signal is obtained, and its continuum extrapolation can be estimated. Modelling the shape of the corresponding spectral function, we subsequently extract the momentum diffusion coefficient, $κ$. For charm (bottom) quarks, the magnetic contribution adds $\sim 30\%$ ($10\%$) to the electric one. The same increases apply also to the drag coefficient, $η$. As an aside, the colour-magnetic spectral function is computed at NLO.
description: 23 pages. v2: clarifications added, data included as ancillary files
Computational & neural investigation of skill learning across speeds in video games
Creators: name: Gianferrara, Pierre
Publisher: name: Carnegie Mellon University
Year: 2024
Subjects: Neuroscience and Physiological Psychology

description:  There has recently been a growing interest in video games as an opportunity to gain insight into the mechanisms of human psychology and skill learning. While past research has started to uncover effects of video game practice on attention, spatial cognition, and perception, it is not yet clear how motor behavior changes as a function of skill and what the precise neural correlates of sensorimotor learning are over the course of skill acquisition. This dissertation proposes to employ a Game-XP perspective (i.e., video games as experimental paradigms) to shed light on key cognitive, motor, and neural dimensions of skill acquisition across sub-second and supra-second time scales. 
This dissertation is broken down into three main parts: The first part’s objective is to characterize and computationally simulate general patterns of human skill learning in video games. Chapter 1 introduces some terminology pertaining to skill acquisition in the context of video games and provides an overview of some key motor correlates of skill. Chapter 2 introduces the adaptive control of thought rational (ACT-R) architecture and presents an instance of a computational ACT-R model of skill learning in the Auto Orbit game, which was used to investigate skill transfer across slow speeds (keypress rates > 500 ms). 
The second part’s objective is to account for and computationally simulate idiosyncratic motor patterns of behavior across speeds and across groups of subjects. Chapter 3 introduces periodic tapping and proposes a novel fast-paced ACT-R motor mechanism that can reproduce humans’ automatic motor behavior at fast speeds. Chapter 4 shows how one can leverage this ACT-R motor extension to account for individual differences across groups of subjects at fast speeds (keypress rates ≤ 500 ms) in the Auto Orbit video game.
 Finally, the third part’s objective is to investigate the neural mechanisms of sensorimotor learning in a game-inspired laboratory self-paced finger tapping task. Chapter 5 introduces electrophysiological correlates of skill acquisition and feedback processing with electroencephalography (EEG) and electromyography (EMG). Chapter 6 presents the results from neural investigations of sensorimotor learning with functional magnetic resonance imaging (fMRI) in the same self-paced finger tapping task. Overall, this dissertation introduces a number of novel methodological strategies which aid in providing an integrative account of computational and neural mechanisms of skill learning in video games as an example of complex task environments
Recollision induced nuclear excitation of $^{229}$Th
Creators: name: Wang, Xu
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Previously we proposed a new approach of exciting the $^{229}$Th nucleus using laser-driven electron recollision [W. Wang et al., Phys. Rev. Lett. 127, 052501 (2021)]. The current article is aimed to elaborate the method by explaining further theoretical details and presenting extended new results. The method has also been improved by adopting the electronic excitation cross sections calculated recently by Tkalya [E. V. Tkalya, Phys. Rev. Lett. 124, 242501 (2020)]. The new cross sections are obtained from Dirac distorted-wave calculations instead of from Dirac plane-wave calculations as we used previously. The distorted-wave cross sections are shown to be 5 to 6 orders of magnitude higher than the plane-wave results. With the excitation cross sections updated, the probability of isomeric excitation of $^{229}$Th from electron recollision is calculated to be on the order of $10^{-12}$ per nucleus per (femtosecond) laser pulse. Dependency of the excitation probability on various laser parameters is calculated and discussed, including the laser intensity, the laser wavelength, and the laser pulse duration.
description: 12 pages, 11 figures
Momentum distribution of dark matter produced in inflaton decay: effect of inflaton mediated scatterings
Creators: name: Ghosh, Avirup
name: Mukhopadhyay, Satyanarayan
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Post-inflationary reheating is a widely discussed mechanism for non-thermal production of dark matter (DM). In this scenario the momentum distribution of the produced DM particles is usually taken to be the one obtained at reheating, red-shifted at later times due to the expansion of the Universe. However, since in such a scenario both the DM and the standard model (SM) fields couple to the inflaton, the DM particles necessarily undergo self-scatterings, as well as elastic and inelastic scattering reactions with the SM bath, all of which proceed through $s-$channel or $t-$channel inflaton exchange. We compute the momentum distribution of the DM particles including the effect of these scatterings, and find that the distributions can be significantly altered, even though DM remains non-thermal throughout the cosmological evolution. We observe that if the inflaton dominantly couples to the SM Higgs boson through a renormalizable interaction, then reheating temperatures and inflaton masses at the TeV scale lead to a large effect from the scattering processes, with the DM-inflaton coupling constrained by the DM density. The scattering effects are found to be sensitive to the duration of the reheating process -- larger the duration, more momentum modes are filled at reheating, leading to an enhanced scattering probability. We also obtain the free-streaming length of such DM using the resulting non-thermal momentum distribution, which can be used to estimate the implications of the Lyman-$α$ constraints on the DM mass. It is observed that in the scenarios considered, including the scattering effects can reduce the DM average velocity at matter-radiation equality, and its free-streaming length, by upto a factor of $40$, thereby making the constraints on light DM produced in inflaton decay significantly weaker.
description: 22 pages, 5 figures, 1 table; v2: comments and references added, version published in Physical Review D
Quantifying geometric measure of entanglement by mean value of spin and spin correlations for pure and mixed states
Creators: name: Frydryszak, A. M.
name: Samar, M. I.
name: Tkachuk, V. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We quantify the geometric measure of entanglement in terms of mean values of observables of entangled system. For pure states we find the relation of geometric measure of entanglement with the mean value of spin one-half for the system composed of spin and arbitrary quantum system. The geometric measure of entanglement for mixed states of rank-2 is studied as well. We find the explicit expression for geometric entanglement and the relation of entanglement in this case with the values of spin correlations. These results allow to find experimentally the value of entanglement by measuring a value of the mean spin and the spin correlations for pure and mixed states, respectively. The obtained results are applied for calculation of entanglement during the evolution in spin chain with Ising interaction , two-spin Ising model in transverse fluctuating magnetic field, Schrödinger cat in fluctuating magnetic field.
description: 19 pages, 1 figure
Type Ia Supernovae: Colors, Rates, and Progenitors
Creators: name: Heringer, Epson
name: Pritchet, Chris
name: Kezwer, Jason
name: Graham, Melissa L.
name: Sand, David
name: Bildfell, Chris
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The rate of type Ia supernovae (SNe Ia) in a galaxy depends not only on stellar mass, but also on star formation history. Here we show that two simple observational quantities ($g-r$ or $u-r$ host galaxy color, and $r$-band luminosity), coupled with an assumed delay time distribution (the rate of SNe Ia as a function of time for an instantaneous burst of star formation), are sufficient to accurately determine a galaxy's SN Ia rate, with very little sensitivity to the precise details of the star formation history. Using this result, we compare observed and predicted color distributions of SN Ia hosts for the MENeaCS cluster supernova survey, and for the SDSS Stripe 82 supernova survey. The observations are consistent with a continuous delay time distribution (DTD), without any cutoff. For old progenitor systems the power-law slope for the DTD is found to be $-1.50 ^{+0.19} _{-0.15}$. This result favours the double degenerate scenario for SN Ia, though other interpretations are possible. We find that the late-time slopes of the delay time distribution are different at the 1$σ$ level for low and high stretch supernova, which suggest a single degenerate scenario for the latter. However, due to ambiguity in the current models' DTD predictions, single degenerate progenitors can neither be confirmed as causing high stretch supernovae nor ruled out from contributing to the overall sample.
Efficient Burst Raw Denoising with Variance Stabilization and Multi-frequency Denoising Network
Creators: name: Li, Dasong
name: Zhang, Yi
name: Law, Ka Lung
name: Wang, Xiaogang
name: Qin, Hongwei
name: Li, Hongsheng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: With the growing popularity of smartphones, capturing high-quality images is of vital importance to smartphones. The cameras of smartphones have small apertures and small sensor cells, which lead to the noisy images in low light environment. Denoising based on a burst of multiple frames generally outperforms single frame denoising but with the larger compututional cost. In this paper, we propose an efficient yet effective burst denoising system. We adopt a three-stage design: noise prior integration, multi-frame alignment and multi-frame denoising. First, we integrate noise prior by pre-processing raw signals into a variance-stabilization space, which allows using a small-scale network to achieve competitive performance. Second, we observe that it is essential to adopt an explicit alignment for burst denoising, but it is not necessary to integrate a learning-based method to perform multi-frame alignment. Instead, we resort to a conventional and efficient alignment method and combine it with our multi-frame denoising network. At last, we propose a denoising strategy that processes multiple frames sequentially. Sequential denoising avoids filtering a large number of frames by decomposing multiple frames denoising into several efficient sub-network denoising. As for each sub-network, we propose an efficient multi-frequency denoising network to remove noise of different frequencies. Our three-stage design is efficient and shows strong performance on burst denoising. Experiments on synthetic and real raw datasets demonstrate that our method outperforms state-of-the-art methods, with less computational cost. Furthermore, the low complexity and high-quality performance make deployment on smartphones possible.
description: Accepted for publication in International Journal of Computer Vision
Effective Low-Complexity Optimization Methods for Joint Phase Noise and Channel Estimation in OFDM
Creators: name: Wang, Zhongju
name: Babu, Prabhu
name: Palomar, Daniel P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Theory (cs.IT)
subject: Optimization and Control (math.OC)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Phase noise correction is crucial to exploit full advantage of orthogonal frequency division multiplexing (OFDM) in modern high-data-rate communications. OFDM channel estimation with simultaneous phase noise compensation has therefore drawn much attention and stimulated continuing efforts. Existing methods, however, either have not taken into account the fundamental properties of phase noise or are only able to provide estimates of limited applicability owing to considerable computational complexity. In this paper, we have reformulated the joint estimation problem in the time domain as opposed to existing frequency-domain approaches, which enables us to develop much more efficient algorithms using the majorization-minimization technique. In addition, we propose a method based on dimensionality reduction and the Bayesian Information Criterion (BIC) that can adapt to various phase noise levels and accomplish much lower mean squared error than the benchmarks without incurring much additional computational cost. Several numerical examples with phase noise generated by free-running oscillators or phase-locked loops demonstrate that our proposed algorithms outperform existing methods with respect to both computational efficiency and mean squared error within a large range of signal-to-noise ratios.
Optimal Storage Allocation for Wireless Cloud Caching Systems with a Limited Sum Storage Capacity
Creators: name: Hong, Bi
name: Choi, Wan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In wireless cloud storage systems, the recovery failure probability depends on not only wireless channel conditions but also storage size of each distributed storage node. For an efficient utilization of limited storage capacity and the performance characterization of allocation strategies, we asymptotically analyze the recovery failure probability of a wireless cloud storage system with a sum storage capacity constraint for both high SNR regime and low SNR regime. Then, we find the optimal storage allocation strategy across distributed storage nodes in terms of the asymptotic recovery failure probability. Our analysis reveals that the maximal symmetric allocation is optimal for high SNR regime and the minimal allocation (with $\lfloor T\rfloor$ complete storage nodes and an incomplete storage node) is optimal for low SNR regime, where $T$ is the sum storage capacity. Based on the numerical investigation, we also show that in intermediate SNR regime, a balance allocation between the minimal allocation and the maximal symmetric allocation would not be required if we select one between them according to SNR.
description: 12 pages, 8 figures, accepted in IEEE transactions on wireless communications
Interface-driven ferromagnetism within the quantum wells of a rare earth titanate superlattice
Creators: name: Need, R. F.
name: Isaac, B. J.
name: Kirby, B. J.
name: Borchers, J. A.
name: Stemmer, S.
name: Wilson, Stephen D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Here we present polarized neutron reflectometry measurements exploring thin film heterostructures comprised of a strongly correlated Mott state, GdTiO$_3$, embedded with SrTiO$_3$ quantum wells. Our results reveal that the net ferromagnetism inherent to the Mott GdTiO$_3$ matrix propagates into the nominally nonmagnetic SrTiO$_3$ quantum wells and tracks the magnetic order parameter of the host Mott insulating matrix. Beyond a well thickness of 5 SrO layers, the magnetic moment within the wells is dramatically suppressed, suggesting that quenched well magnetism comprises the likely origin of quantum critical magnetotransport in this thin film architecture. Our data demonstrate that the interplay between proximate exchange fields and polarity induced carrier densities can stabilize extended magnetic states within SrTiO$_3$ quantum wells.
description: 5 pages, 4 figures
Constraints on annihilating dark matter in the Omega Centauri cluster
Creators: name: Chan, Man Ho
name: Lee, Chak Man
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Recent gamma-ray and radio studies have obtained some stringent constraints on annihilating dark matter properties. However, only a few studies have focussed on using X-ray data to constrain annihilating dark matter. In this article, we perform the X-ray analysis of annihilating dark matter using the data of the Omega Centauri cluster. If dark matter is the correct interpretation of the non-luminous mass component derived in the Omega Centauri cluster, the conservative lower limits of thermal dark matter mass annihilating via the $τ^+τ^-$, $b\bar{b}$ and $W^+W^-$ channels can be significantly improved to 104(43) GeV, 650(167) GeV and 480(137) GeV respectively, assuming the diffusion coefficient $D_0 \le 10^{26}(10^{27})$ cm$^2$/s. These constraints can safely rule out the recent claims of dark matter interpretation of the gamma-ray excess and anti-proton excess seen in our Galaxy. Generally speaking, the conservative lower limits obtained for non-leptophilic annihilation channels are much more stringent than that obtained by gamma-ray analysis of nearby dwarf galaxies. We anticipate that this would open a new window for constraining annihilating dark matter.
description: Accepted in Phys. Rev. D
Operator self-similar processes and functional central limit theorems
Creators: name: Characiejus, Vaidotas
name: Račkauskas, Alfredas
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60B12, 60F17, 60G18

description: Let $\{X_k:k\ge1\}$ be a linear process with values in the separable Hilbert space $L_2(μ)$ given by $X_k=\sum_{j=0}^\infty(j+1)^{-D}\varepsilon_{k-j}$ for each $k\ge1$, where $D$ is defined by $Df=\{d(s)f(s):s\in\mathbb S\}$ for each $f\in L_2(μ)$ with $d:\mathbb S\to\mathbb R$ and $\{\varepsilon_k:k\in\mathbb Z\}$ are independent and identically distributed $L_2(μ)$-valued random elements with $\operatorname E\varepsilon_0=0$ and $\operatorname E\|\varepsilon_0\|^2
description: 22 pages
Quantum topological phase transitions in skyrmion crystals
Creators: name: Mæland, Kristian
name: Sudbø, Asle
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Topological order is important in many aspects of condensed matter physics, and has been extended to bosonic systems. In this Letter we report on the nontrivial topology of the magnon bands in two distinct quantum skyrmion crystals appearing in zero external magnetic field. This is revealed by nonzero Chern numbers for some of the bands. As a bosonic analog of the quantum anomalous Hall effect, we show that topological magnons can appear in skyrmion crystals without explicitly breaking time-reversal symmetry with an external magnetic field. By tuning the value of the easy-axis anisotropy at zero temperature, we find eight quantum topological phase transitions signaled by discontinuous jumps in certain Chern numbers. We connect these quantum topological phase transitions to gaps closing and reopening between magnon bands.
description: 6+17 pages, 2+3 figures, includes supplemental material, accepted in Physical Review Research
Constraining annihilating dark matter by radio continuum spectrum of the Large Magellanic Cloud
Creators: name: Chan, Man Ho
name: Lee, Chak Man
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Recent radio observations have obtained stringent constraints for annihilating dark matter. In this article, we use the radio continuum spectral data of the Large Magellanic Cloud (LMC) to analyze the dark matter annihilation signals. We have discovered a slightly positive signal of dark matter annihilation with a $1.5σ$ statistical significance. The overall best-fit dark matter mass is $m_{\rm DM} \approx 90$ GeV, annihilating via $b\bar{b}$ channel. We have also constrained the $3σ$ lower limits of dark matter mass with the standard thermal dark matter annihilation cross section for the $e^+e^-$, $μ^+μ^-$, $τ^+τ^-$ and $b\bar{b}$ channels.
description: Accepted in ApJ
The COSMOS [OII] Survey: Evolution of Electron Density with Star Formation Rate
Creators: name: Kaasinen, Melanie
name: Bian, Fuyan
name: Groves, Brent
name: Kewley, Lisa
name: Gupta, Anshu
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Star-forming galaxies at $z > 1$ exhibit significantly different properties to local galaxies of equivalent stellar mass. Not only are high-redshift star-forming galaxies characterized by higher star formation rates and gas fractions than their local counterparts, they also appear to host star-forming regions with significantly different physical conditions, including greater electron densities. To understand what physical mechanisms are responsible for the observed evolution of star-forming conditions we have assembled the largest sample of star-forming galaxies at $z\sim 1.5$ with emission-line measurements of the $\mathrm{[OII]} λλ3726,3729$ doublet. By comparing our $z\sim 1.5$ sample to local galaxy samples with equivalent distributions of stellar mass, star formation rate and specific star formation rate we investigate the proposed evolution in electron density and its dependence on global properties. We measure an average electron density of $114_{-27}^{+28} \, \mathrm {cm}^{-3} $ for our $z\sim 1.5$ sample, a factor of five greater than the typical electron density of local star-forming galaxies. However, we find no offset between the typical electron densities of local and high-redshift galaxies with equivalent star-formation rates. Our work indicates that the average electron density of a sample is highly sensitive to the star formation rates, implying that the previously observed evolution is mainly the result of selection effects.
description: 16 pages, 6 Figures